Little Help Please :)

[sabo99]

Good morning,

I was on here previously but was unable to remember my username. So i created a new one. I have a 2007 GZ250 with 2300 miles on it. It has been in for the services needed to this point, and i change the oil myself. Using 10W40 Valvoline motorcycle oil. The problem i am having is that when i go on extended rides, after about 20-30 miles, i start to just lose all power all of a sudden, and the throttle does nothing. Will be cruising along at 55 mph, and then i just lose all power, bike wont rev up by giving it throttle. Engine stays running. I downshift, and it will take off again once i get back down to lower gears. It is fine until the bike gets warm after riding a while. Air filter is good, oil is fresh, gas is fresh, and i have ran seafoam through it already this year. This also happened last year. I am fine as long as i stay off the highway and dont cruise at 55 for a while. Any help, or ideas would be great. I am thinking about checking the spark plug. Replacing it. Thought maybe a carb issue, but it should be clean. I always store with Stabil, and run some seafoam through it beginning of summer each year. Thanks

Paul

[geezer]

yes check your plug for color, and i bet youll find it white. i think your running lean due to the increase in speeds being a problem. at higher speed the bike will intake more air and give you a leaner mixture. you might have an intake leak. check out the plug and get back to us

[Water Warrior 2]

Good call with that last idea.

Have you made any changes to the air box/air intake system ?

[sabo99]

I havent made any changes to the bike at all. Still stock... I went out to ride it to work this morning. It starts, runs for a few seconds, then dies. So it is looking to me to be a fuel delivery issue. Which backs up the lean statement. It must be struggling for fuel. Since i let it sit this week, now it is worse. I had used seafoam in the tank. So that musta broke up stuff. I will have to drain the tank and clean the petcock. Question before i do this. Anything bad by me removing the screen in the Petcock assembly to keep it from plugging up, and then running a inline fuel filter to catch anything. Would be a lot easier to just replace the cheap filter now and then rather than pulling the tank. Thanks again for any help. Glad its a 3 day weekend. Wanted to ride to work tomorrow though.. Oh well

[blaine]

I would take your fuel hose off at the carb and check for fuel flow.I'm guessing that it's your carb that needs cleaning,not your petcock.I would NOT remove the screens in the petcock.They are there to keep dirt & rust out of the petcock,also if you remove them you will have no reserve,as the screen is part of the pickup tubes.Lots of members have been stranded by the pickup tube falling off the petcock,and leaving them with no reserve.If you want to clean the tank,you should only need to do it once,for peace of mind.I would add a inline filter,as it traps finer particles than the screens in the petcock.Good luck.
:cool: :)

[sabo99]

Cool... Thanks. I would have thought the Seafoam would have cleaned up the carb. Think i can just spray some carb cleaner in where the fuel line goes in and let it sit for a while? Or do i have to remove the carb and clean it out? I only have 2000 miles on it. Thanks

[blaine]

Cool... Thanks. I would have thought the Seafoam would have cleaned up the carb. Think i can just spray some carb cleaner in where the fuel line goes in and let it sit for a while? Or do i have to remove the carb and clean it out? I only have 2000 miles on it. Thanks
You can try that first,once you determine that you have good fuel from the tank.It takes very little dirt or sediment to play havoc with these carbs.
:) :2tup:

[mrlmd1]

Check to see if there's free flow of fuel out the petcock - put it on PRIME, remove the hose from either end and see how fast fuel flows, and no dirt.
Also put it on RUN, apply some sort of vacuum and see if it flows. You could be clogged up some inside those screens on the intake tubes to the petcock limiting high flow when needed.

[sabo99]

Thats what i am wondering. Will try to work on it this weekend and post what i find out. Thanks

[geezer]

from personal experience, tank strainer. hopeuflly you fnd low fuel flow there cause its much faster and easier to clean the tank than it is to do the carb. but personally id do the whole fuel system in one shot, it only takes a few hours for most people and then you will have a trouble free fuel system

[Cooteboy]

Just a thought about the stabil. Did you use the "ethanol" version? I work at Napa - after several years of wrenching. This year and last I have a seen multiple vehicles, lawn mowers, chain saws, boats, and the like having terrible carb/fuel issues because of the increase in ethanol. If you read the stabil label it states to be good for 3-6 months of storage. You actually would have been better off using the seafoam as a stabilizer as it is good for 2 years of storage. Although neither one is really that great for ethanol.

We've been carrying a product called Startron at my work. I personally have witnessed it turn a 3 gallon tank of nasty stinky orange un-burnable fuel into clean smelling, clear and runnable fuel. Absolutely incredible! It is the ONLY thing I am using now to store my bikes.

Just a thought - beware the ethanol. Also, what grade fuel have you been using? The higher the octane - the cooler the burn.

[geezer]

dont make her think she needs to run high octane fuel man :tdown: 87 for these bikes

[Cooteboy]

Sorry geezer,

Didn't mean to imply that she "had to" purchase premium, just stating a thought. Anyone suffering from heat related issues should try running premium fuel to see if it improves. If you think about it, it's only 20-30 cents more per gallon making it a mere $1.25 extra per tank to try out a couple times.

[geezer]

hmmm i guess. never thought of using fuel like that. sounds li a band-aid fix to me. sure it might burn cooler but it also burns slower, im sure a gz would puke its guts out on premium fuel.

[Water Warrior 2]

The higher the octane the more controlled burn. These bikes are designed to burn almost anything combustable in 3rd world countries. 87 is what is recommended. Why stray, I'm sure the Suzuki engineers have some fine collective knowledge.

[Cooteboy]

Doesn't anyone read their manual like I do? :retard: OK, so I have been a bit more intimate with mine being as I had the bike dismantled in my living room.

Not to step on toes ...

Section 1-3 of the Service manual bottom of the page under fuel and oil recommendations
"FUEL"
"Use unleaded gasoline that is graded 91 octane or higher."

Premium in my area is 92 octane, so that's all I'm using. This air cooled engine does better, and would probably last longer on premium fuel because it's easier on the components.

My wife's supercharged buick is the same way. In fact, there was a factory recall on her car because too many customers were ignoring the "premium" recommendation and using the cheap fuel - causing the exhaust to run extremely hot and in doing so causing engine fires from weeping valve cover gaskets. If you run cheap fuel in that car, it runs like a pig.

[Water Warrior 2]

Please keep in mind there are 2 ways to determine octane. 2 separate types or methods. The method referrred to in the manual is probably the other method not commonly used in North America and it's 91 or 92 value is equal to the method used to determine 87 octane in N.A. The GZ is designed with a lower compression to allow for 3rd world fuels.
Your wife's super charged Buick does require high octane without a doubt and would probably suffer dire results with it's more modern sophisticated engine design. I'll bet it would go like a bat with 94 octane and no corn products added to the mixture.
The GZ is what it is and regular fuel is the only requirement to keep it happy. If your personal comfort is enhanced by using premium gas just do it and be happy.

[mrlmd1]

Premium fuel is easier on the components of the engine? Based on what evidence? Where does something like that come from?
It's almost impossible to get people to give up their bias that premium fuel is "better" than regular fuel. Premium fuel is only different from regular in having additives to slow down the combustion process to prevent pre-ignition or pre-detonation in a high compression engine, which the GZ is not. It actually has less power or energy in it per cc. or oz. of fuel compared to regular, gives worse performance, gets worse gas mileage, and is more expensive. The GZ engine was designed to use regular fuel, period- you want to use premium, for whatever reason, go for it, it's your bike, your pocketbook. Do a little research on numerous threads on this and other forums and on the web about what exactly high octane fuel is and you'll be quite surprised.

[mrlmd1]

Here's a little partial explanation from an auto and bike mechanic on another forum : First a comment by another member, than his explanation.

Higher octane fuel resists detonation. Another way of looking at it, is it's harder to light and actually has less energy. With a non-sophisticated engine (no variable timing, knock sensors, etc.) there's no advantage to using higher octane than required to avert detonation.

Octane does not affect potential energy level of gasoline. Octane affects how quickly the flame front propagates through the combustion chamber. Burning fuel raises the temperature of the gasses in the combustion chamber, increasing the temperature of the gasses in the combustion chamber increases the pressure those gasses exert on the walls of the combustion chamber (which includes the top of the piston), and it is the pressure on the top of the piston that pushes the piston down, which pushes on the rod, which pushes on the crank, etc. Since the flame front propagates slower, the maximum cylinder pressure may not be generated until well after the piston passes top dead center on the power stroke, which means the push on the top of the piston does not begin until after top dead center. Best power is delivered when the push begins just after the piston passes top dead center. If the push doesn't begin until 20* after top dead center, no power is generated for that 20* arc of crankshaft revolution. That is why higher octane fuels require advanced ignition timing to make power--the flame front needs more time to generate heat and pressure. In some engines, higher octane fuels simply don't burn as efficiently as lower octane fuels. It is the lower efficiency that results in lower engine output, not lower energy content of the fuel.

[sabo99]

Wow, lots of good info here. I have always used 93 octane in my GZ. To update this topic, i havent had time to do anything to it. However it seems to be running ok now. I rode it to work yesterday, and today. Started up just fine. Maybe a few more days of it sitting with the seafoam in the carb cleaned it up some. I am going to filler up again on friday. Will spray some carb cleaner in the tank this time to run through it. Just seems weird that i would need to clean out the carb and such with only 2000 miles on it. I always run higher octane gas, stored correctly in the winter, etc. I do find the above topic on the Stabil interesting. I had put some in my moms tiller last winter, and it was a pain in the rear getting that thing started. I had to spray the inside of the carb with carb cleaner, and let it sit to get it to finally fire up. I will use some Seafoam this winter and see if my results change any. Thanks again for all the help. With the price of gas, i rely on the bike to get to work. Saves money when i dont have to drive the truck.

[alantf]

Just seems weird that i would need to clean out the carb and such with only 2000 miles on it.

The additive that I use advises using it in the first three tankfuls of a new vehicle, then every 4000 km. :)

[Cooteboy]

Wow,

That was quite a response from everyone.

mrlmd1 "Premium fuel is easier on the components of the engine? Based on what evidence? Where does something like that come from?"

Sorry mrlmd1 - that was more my opinion than anything. Despite the fact that I was somewhat mislead in my understanding, the engine will still run cooler on premium. Less heat means less stress and wear - ie easier on the components - that's where my opinion was coming from.

I have been re-informed by everyone about the premium fuel, and I would like to thank everyone - that's what we're on a forum for right - to learn and help where we can.

[geezer]

goood save cooteboy :2tup: we about had you backed into a corner :twisted:

[mrlmd1]

Here's the same info, from a Kawasaki Ninja site, same particulars as the GZ engine (ie. low compression)

What kind of fuel should I use?
From Ninja250Wiki
Jump to: navigation, search

This is real easy: The owner's manual specifies 87 octane unleaded gasoline. Anything else is like throwing money out the window. If you thought the manual said to use 91 octane, you read it wrong.

Confusion comes about because the method of determining the octane number is different in North America than in most of the rest of the world. Other countries use the Research Octane Number (RON), but if you look at the yellow octane sticker on pumps in the US, you'll see a notation that (R+M)/2 is how octane is calculated. (R+M)/2 is an averaging of the RON and the Motor Octane Number (MON). The important bit to know is that 87 in the US is equal to 91 in countries using the RON standard.


Having too high an octane is never harmful, but having too low can be. That said, there's still no point in using an octane higher than what the factory says, unless the engine's knocking. With an older engine, sometimes you get knocking unless you go with a higher octane.

You're not going to get a performance gain with a higher octane fuel. Octane (which is the only difference between the cheap gas and the expensive gas at a station) is a detonation inhibitor. It does not make gasoline burn better in any way - it actually prevents the gas from burning too soon. This is very useful in a high-compression, high-performance engine, like those found in sports cars and high-performance motorcycles. That's why it's recommended for those engines. However, for the Ninja 250, having higher octane produces no benefit: detonation won't occur with 87 octane gas, and it will continue not to occur with 89 or 91 octane gas. It is literally blowing money out your tailpipe. Since higher octane only increases the ignition energy required to start the burning reaction, it may cause a very slight reduction in performance compared to lower octane gasoline, but it would be too small to be measured, much less noticed.

In other words, 87 octane and 91 octane gasoline perform exactly the same in a Ninja 250 engine. There is no benefit (but also no harm) to running 91 octane gasoline, and it costs 20 cents more per gallon, typically. Over the course of 10,000 miles at 60 mpg, you'll spend an extra $33 on nothing.

At higher elevations, usually in western mountain states, octane numbers will often be lower to compensate for different combustion conditions. You should be able to use the lowest-octane gas sold there in your Ninja 250, but if you experience any knocking or unusual noises from the engine, switch to a higher octane fuel or a different brand.


And here's another similar comment--------

Welp I decided to start using 91 octane gas. I have unlimited money so I also only use Evian sparkling water in my toilet and I make sure that I drop fresh air fresheners into my garbage bags right before I seal them and put them outside in the trash (so if/when they break it doesn't make bad odors inside the garbage truck).

I never get why such simple premises like octane can really cause debates. People tie higher octane gas for "high performance" engines together and assume that it's the gas that's doing it. When in reality octane has nothing to do with performance. Nothing. nadda. zip (in reality it can actually hurt performance). If you go to the track and spend $7/gal for some 114 octane gas guess what you should expect? You'll burn your 02 sensor out (on your car) and not gain a single horsepower. Octane is a measurement of detonation resistance and that is IT. Higher combustion chamber pressures (from perhaps a super/turbo charger or domed pistons) present greater risk towards detonation and need more detonation resistant fuel. It'd be like a firefighter showing up and putting out a duraflame log with a fire hose. Sure it works, but it's way overkill.



In other words, use regular gas for the GZ.

[Cooteboy]

mrlmd1 and WW..

I would like to apologize for my mistake. You were both correct about the minimum requirement on the GZ250. I only read the beginning of the manual - in the back of the manual in section 7-23 it states the method used for determining octane rating. In NA all that is required is an octane rating of 87. I was wrong - I apologize.

mrlmd1 - Dang! You seem to have some extreme views on this subject. I was merely giving my opinion - which I am entitled to - just as you are entitled to yours.

In my area there are a few stations where you can aquire non-ethanol fuel in the summer. It is only available in the premium high octane fuel though. I would do some research and see if it is available in other areas of the country. That alone is worth 30 cents a gallon to me.

Also in my area, several stations tend to sell watered down regular fuel - literally. If you purchase the lowest octane fuel, you will often times need to buy a bottle of "heat" to rid yourself of the water - which runs $2.99 per bottle.

mrlmd1 - I would like to thank you for your persistence and information - it has helped me to understand several points more clearly. I have always known - per my experience on many different vehicles - that higher octane premium fuel runs the engine cooler but, didn't understand how or why.

Have you ever worked on a A/C system? It works much the same as the engine using pistons and vacuum/compression. Air conditoning does not actually "make" cold air - instead it removes heat from it's surroundings creating the effect of cold air. The process of changing refrigerant from a liquid to a gas takes a great amount of energy - in the form of heat. The higher the temperature required to make the conversion, the greater the amount of engergy required, the greater the amount of heat absorbed/exchanged, ie the colder the A/C. If the premium higher octane fuel truly does require a higher temperature to become a combustilbe gas, then it would absorb more heat in order to burn - in turn reducing the operating temperature of the engine. Just because the premium fuel requires more heat to burn does not mean that it burns hotter, quite the opposite actually.

That is my theory and experience on the subject - it makes sense from a chemistry/physics standpoint - disapprove/disagree if you like. I have now done some research online and have not found anyone who has experienced - or at least documented - what I have observed. I am very interested in this concept though and would like to see a bit of research done. If I am correct, then I would think that air cooled engines would benefit somewhat from this - not at all in performance but, perhaps in longevity.

Regardless, if you want to run regular - then by all means run regular fuel (it's recommended by the manufacturer) and it will surely get you from point A to point B. In turn, if you want to run premium - feel free to do so - it is your perogative (just don't mention it on this forum - they'll back you into a corner :biggrin: )

[geezer]

yes we will, oh and dont you dare mention anyting about suzuki engine guards either, our attack squad will come after you.


as far as the fuel thing goes, i always have disagreed with people who state high octane fuel makes yor car run better blablablablab. but one guy really was so sure that it atlest give you better fuel milage/ so i tested this and used midgrade instead, no milage increase at all and i spent 10 more dollars to fill :itsokay:

[sabo99]

Ok, I am still having this issue after several tanks of fuel with Seafoam in them. I am sure it is not due to the carb. I am leaning towards the Petcock assembly. I think when i am at higher RPM's/Speed, the engine isnt getting enough fuel. Is it ok to keep the Petcock in the Prime position while riding? I want to try this since it will give constant flow to engine. Just to test my theory. If that keeps my issue from happening, then i will know my problem is there somewhere. I just dont want to mess anything up while trying it. I know to never leave it in Prime with the bike off, but is it ok to leave it in Prime if the bike is running? That is my question. Thanks

Paul

[blaine]

Ok, I am still having this issue after several tanks of fuel with Seafoam in them. I am sure it is not due to the carb. I am leaning towards the Petcock assembly. I think when i am at higher RPM's/Speed, the engine isnt getting enough fuel. Is it ok to keep the Petcock in the Prime position while riding? I want to try this since it will give constant flow to engine. Just to test my theory. If that keeps my issue from happening, then i will know my problem is there somewhere. I just dont want to mess anything up while trying it. I know to never leave it in Prime with the bike off, but is it ok to leave it in Prime if the bike is running? That is my question. Thanks

Paul
Yep,fine to keep it on"pri" when the bike is running. :) :cool:

[sabo99]

Awesome... Thanks

[mrlmd1]

But make sure you put it back in the RUN position when you are done, just in case you have a leaky carb float.

[geezer]

it takes 10 mins to get the tank off if your not good with tools. take it off and drain it, then remove the strainer with the two phillips head screws under the tank, tada. go for it man. then with the tank off the carb is self explanitory, get r done

[dspdr]

Hello I have a 2007 GZ250 that was sitting for about a year. I just put in new battery, drained & changed the gas and changed the oil. Now wehen I ride it there is a little smoke that comes out from between the top and lower engine casing. Also when I stop and let go of the throttle the engine cuts off. I turned the idle up and it works for that ride but the next day its back to cutting off. Do I need a CARB rebuild or would a HEAD gasket leak cause it to cut off???? There is also a lack of power when riding/... HELP?????

[geezer]

the smoke must be some oil burning off so you might have an oil leak at the headgasket. i have one there but it doesnt smoke at all so maybe your bike has a really bad headgasket but i have never seen one smoke before. first thing you should do is wash the bike if its dirty paying special attention to that area. also yea clean the entire fuel system. just gotta do it man

[Gz Rider]

...

[mrlmd1]

By choke closed, you mean ON? By choke open, you mean OFF? These bikes do not have a choke like on a car with a butterfly valve closing off the air supply. It is an "enricher circuit" supplying higher than normal amounts of fuel to enrich the mixture accomplishing basically the same thing.

[mrlmd1]

If the intake to the petcock in the normal RUN position is clogged or restricted due to crap and debris in the tank plugging up the little screen over the intake, it would also get clogged in the PRIME position as this draws fuel from closer to the bottom of the tank. I doubt the petcock is your problem. You can test fuel flow through it by removing the hose on the bottom and applying a vacuum to the petcock and see how fast it flows in the run position, and how fast it flows in prime position, Just be sure to have a container to catch it in.

[Gz Rider]

...

[dspdr]

Hello I have a 2007 GZ250 that was sitting for about a year. I just put in new battery, drained & changed the gas and changed the oil. Now when I ride it there is a little smoke that comes out from between the top and lower engine casing. Also when I stop and let go of the throttle the engine cuts off. I turned the idle up and it works for that ride but the next day its back to cutting off. Do I need a CARB rebuild or would a HEAD gasket leak cause it to cut off???? There is also a lack of power when riding/... HELP?????

I see four issues here.

*******Check the oil before you do anything else and keep a close eye one it***********

First, the engine should not smoke. As geezer points out you must be burning some oil somewhere as normal engine exhaust is not usually visible. I assume the smoke is whiteish indicating oil burning and not black indicating possible carburator problems. I also saw your post regarding your inoperable choke cable. Have you resolved that? If I'm not mistaken running the bike with the choke closed (or closed partially) would result in black smoke from the exhaust once the bike is warmed up. Can someone back me up on that?

Second I'm not sure where exactly the smoke leak is. Can you be more specific. If you don't already have it, download the service manual and parts manual to better identify where the leak is. Alternately you could post a pic with an arrow.

Third, the cutting off issue may just be idle adjustment which should be 1300 RPM (+100 RPM). The choke must be open after the bike has warmed up. If the bike will not hold this idle without cutting off, I might clean the carb and see what that did. Sitting a year (and maybe more for all you know) usually leads to a plugged carb. I don't think a head gasket leak would cause you not to be able to idle unless it was really bad. You may easily have a head gasket leak though that is causing the smoke.

Fourth, the lack of power could be alot of things. Improper choke position could be one. When you say lacks power, how fast can you get this bike to go? How are you defining the lack of power?

For more help post more details on the color and location of the smoke leak. Tell us if you are able to properly operate your choke now.


yes the smoke was white. it has stopped but it was coming out the first two days after getting it started after a year. The oil level is fine..i am about to order the choke cable and control from a guyy here on the site, i just got the manual.. now to the idle, i use my wire that i have attached to the choke cable to start the bike. once started i ride it for about a block or more and then i return the choke to the normal off position. the bike is a little sluggish but it runs at a reduced speed compared to how it ran a yr ago. but when i stopp and release the throttle the bike goes to idle and then cuts off. it will staart right back up but i have to keep on the throttle no matter how warmed up it is. I think i need to rebuild the carb , but the smoke on the 1st two days threw me off... A person told me if may be head gasket but i had never heard of that making the bike cut off. thank you all for the quick replies..

[blaine]

I would say that it is just residue burning off after sitting around for a year.You can try some Sea Foam in a tank of fuel to see if it helps.It may take a couple of days to see the full effect.It may save you taking the carb off.
:cool:

[Gz Rider]

...

[dspdr]

Gzrider, thank you...
I took it to the shop and they are telling me $600 to fix head gasket and rebuild carb.. i think that is a little high, and based on what you told me the gasket should not be the problem as to why it cuts off.. i am going to have them rebuild the CARB only and see if i can ride it without it cutting off. if so i am good til next yr when i will be moving up to a 500 or 650.. this bike will become a training bike for the whole family. thanks to everyone for the help..

[Gz Rider]

...

[alantf]

this bike will become a training bike for the whole family.

Don't forget that a training bike needs to be "better" than a "normal" bike, so that the learner can concentrate on his/her riding skills, with a bike that behaves correctly, rather than having to deal with any mechanical problems as they learn. :) Make sure it's 100% before you let them on it. :2tup:

[Water Warrior 2]

this bike will become a training bike for the whole family.

Don't forget that a training bike needs to be "better" than a "normal" bike, so that the learner can concentrate on his/her riding skills, with a bike that behaves correctly, rather than having to deal with any mechanical problems as they learn. :) Make sure it's 100% before you let them on it. :2tup:
Absolutely agree with that. You wouldn't take flying lessons in an almost good enough aircraft so why take riding lessons on an almost good enough bike.

[dspdr]

u guys r right.. i just hate spending the money 4 something thats not the main problem. the shop would not give me a straight answer as 2 why it cuts off, they want 2 fix both issues that i told them about..they said then it will be a smooth runnin bike. so i may just bite the bullet..n fix everything.. thanks 4 the help. this is a great site..

[Gz Rider]

...

[jonathan180iq]

The fact that the smoking has stopped and you don't see oil seeping out from around the base of the head tells me that there isn't a head gasket problem.

Engines that have been sitting for a long time will tend to smoke. Nothing weird about that. If it doesn't come back, there isn't a problem.
And if there isn't a problem, then there is no reason throwing money at it.

To deal with the bike cutting off as it comes down to idle speed, have you tried simply adjusting the idle speed? There is large screw on the side you can turn to raise the idle just a bit.

[blaine]

The fact that the smoking has stopped and you don't see oil seeping out from around the base of the head tells me that there isn't a head gasket problem.

Engines that have been sitting for a long time will tend to smoke. Nothing weird about that. If it doesn't come back, there isn't a problem.
And if there isn't a problem, then there is no reason throwing money at it.
:2tup: :plus1: :plus1: