Bike was sitting Now won't start

[QUICKSTRONG]

OK I am brand new to this forum as I just brought home my first Suzuki GZ250 today. A guy had it sitting in his garage back in the corner all covered with dust and cobwebs. It looked really sharp no rust no dents just really dusty. Anyway $600 later I am home trying to start this and it turns over but no fire. It has been sitting for a long time, for some reason there was no gas at all in it. So I added some gas and have been trying to start it. Can anyone give me some directions how to start a bike that has been sitting for a long time. all the lights work so i dont think it is electrical. thanks for any help, I hope I didnt throw away 600 bucks

[JohnC]

Did you set the petcock to "PRI(me)"? Have you confirmed fuel is getting to the float bowl? Have you pulled the plug out to confirm it is firing? Is it wet with fuel?

The most common cause of a formerly running bike that has been sitting for a long time not starting is a gummed up carburetor.

[QUICKSTRONG]

Did you set the petcock to "PRI(me)"? Have you confirmed fuel is getting to the float bowl? Have you pulled the plug out to confirm it is firing? Is it wet with fuel?

The most common cause of a formerly running bike that has been sitting for a long time not starting is a gummed up carburetor.
Thanks, Yes it has spark and compression I am pretty sure it is a fuel problem.
I have 3 quick questions on this :
Can someone point me in the direction where I can find the directions or a video on how to remove the carb and clean it? :??:
Also what size is the plug 18mm? Where do it get a spark plug wrench for this? :??:
How do I remove the backrest assembly the torx screws just turn in the chrome bar. :??:

Thanks I appreciate all the help.
If there are visuals or videos out there that makes things easier for me as I am a visual leaner. :biggrin:

[jonathan180iq]

If you have a socket set, you should be able to find the right size for the spark plug. This doesn't require anything fancy like you would use on DOHC car. Just get a deep socket and pull the plug. You need to do this anyway if you are going to determine whether or not you have spark.

There isn't a video that we have of the GZ carb, but there are tons of photos and helpful guides on here. Do a search for:

(Needle Shim Mod)
(Jetting: Part 1 & 2)
(Jaime Rejet)
...There are loads of discussions about carb work on this forum and lots of helpful photos too.
Seriously, once you pull the carb once, you'll see how easy it is.

You can access most points on the carb by loosening the carb boots on both the intake and engine side and turning to 90 degrees. Don't be scared with you spill some fuel. That's going to be normal. You'll need some carb cleaner spray, nitrile gloves, and some eye protection. You need to clean the shit out of the carb and then get some fresh fuel in there with some sort of carb cleaner in there for good measure. (Seafoam/Berrymans/Marvel Mystery Oil) Something like that.

Also, since your tank sat bone dry for who knows how long, I would flush it with some kerosene. I would then install a secondary fuel filter between the petcock and the carb inlet. Might as well do this right while you have everything apart.

[QUICKSTRONG]

If you have a socket set, you should be able to find the right size for the spark plug. This doesn't require anything fancy like you would use on DOHC car. Just get a deep socket and pull the plug. You need to do this anyway if you are going to determine whether or not you have spark.

There isn't a video that we have of the GZ carb, but there are tons of photos and helpful guides on here. Do a search for:

(Needle Shim Mod)
(Jetting: Part 1 & 2)
(Jaime Rejet)
...There are loads of discussions about carb work on this forum and lots of helpful photos too.
Seriously, once you pull the carb once, you'll see how easy it is.

You can access most points on the carb by loosening the carb boots on both the intake and engine side and turning to 90 degrees. Don't be scared with you spill some fuel. That's going to be normal. You'll need some carb cleaner spray, nitrile gloves, and some eye protection. You need to clean the shit out of the carb and then get some fresh fuel in there with some sort of carb cleaner in there for good measure. (Seafoam/Berrymans/Marvel Mystery Oil) Something like that.

Also, since your tank sat bone dry for who knows how long, I would flush it with some kerosene. I would then install a secondary fuel filter between the petcock and the carb inlet. Might as well do this right while you have everything apart.
OK I had the carb cleaned today but we still cannot get the bike to fire at all. Not sure what is going on here?
I can get the ike to sputter a little when I spray starter fluid directly in the plug hole but that is it.
Any ideas? I am starting the bike using a battery pack the battery on the bike is dead.
Also the plug looks dry like its not getting fuel even after the carb clean today. Do I need a full tank of fuel? I only have a gallon in there now.
Should the petcock be on prime, reserve or on? there is no off.
Thanks for any help I appreciate it.

[JohnC]

Put it on prime for now to eliminate that as a possible issue. Be sure to turn it off prime when you're not trying to start it. Also, check the vacuum hose from the intake to the petcock. If it is broken or missing it'll make the mixture too lean and make it harder to start.

I'm not sure what you mean by "I can get the [b]ike to sputter a little when I spray starter fluid directly in the plug hole". I assume you mean you then put the plug back before you try? Squirt a little (very little) gas in instead. Another trick you can try (use appropriate cautions!) is to pull the plug after attempting to start it and put a lighted match in the plug hole. KEEP YOUR FINGERS CLEAR!!! If there's air/fuel in the cylinder it'll light with a "woosh!!"

Regardless, it sounds like you're not getting fuel. You cannot clean the most critical passages (the pilot and choke circuits) without removing and disassembling the carb.

[alantf]

check the vacuum hose from the intake to the petcock. If it is broken or missing it'll make the mixture too lean

?????????????? I don't think you actually know what the vacuum pipe does. Vacuum from the engine opens the petcock, and allows fuel to flow to the carb. (rather like an on/off switch) It's NOTHING to do with the mixture, which is the only thing that could make it lean. Please don't confuse the newbies. :)

[Water Warrior 2]

check the vacuum hose from the intake to the petcock. If it is broken or missing it'll make the mixture too lean

?????????????? I don't think you actually know what the vacuum pipe does. Vacuum from the engine opens the petcock, and allows fuel to flow to the carb. (rather like an on/off switch) It's NOTHING to do with the mixture, which is the only thing that could make it lean. Please don't confuse the newbies. :)
I think JohnC is thinking a leaky vacuum line will suck air into the engine and therefore lean out the fuel mixture. I'm sure he will clarify that for us.

[JohnC]

Yes, if the vacuum line is missing or broken two things happen. First, the fuel won't flow in "on" or "reserve" and secondly, the engine will suck extra air in through the vacuum port, which is after the fuel metering section of the carb. This causes an extremely lean condition at idle and low speeds by reducing the flow through the metering section of the carb and hence reducing the amount of fuel metered. This mix is then combined with the unmetered air from the vacuum port resulting in a very lean mixture delivered to the cylinder. On a single cylinder engine the leak is sufficient to prevent the engine from idling, especially when the choke is off.

[Water Warrior 2]

:2tup: Yippy, I finally nailed one.

[alantf]

I think JohnC is thinking a leaky vacuum line will suck air into the engine and therefore lean out the fuel mixture. I'm sure he will clarify that for us.

I hope he does clarify what he thinks. All a leaky vacuum pipe will do is to stop it sucking a vacuum, which means that the petcock valve won't open, so fuel won't flow to the carb.

[blaine]

Yes, if the vacuum line is missing or broken two things happen. First, the fuel won't flow in "on" or "reserve" and secondly, the engine will suck extra air in through the vacuum port, which is after the fuel metering section of the carb. This causes an extremely lean condition at idle and low speeds by reducing the flow through the metering section of the carb and hence reducing the amount of fuel metered. This mix is then combined with the unmetered air from the vacuum port resulting in a very lean mixture delivered to the cylinder. On a single cylinder engine the leak is sufficient to prevent the engine from idling, especially when the choke is off.

Yep....Any vacuum leak will cause a lean condition. ;) :)

[JohnC]

All a leaky vacuum pipe will do is to stop it sucking a vacuum, which means that the petcock valve won't open, so fuel won't flow to the carb.

It's not that simple, as I stated above. When the vacuum line is connected to the petcock, there is no air flowing through the vacuum port once the petcock opens. When the line is broken or disconnected there is a steady flow of unmetered air into the engine's intake, and no fuel delivered by the carb to go with it. The carb meters fuel based on the amount of air flowing through it. Allowing air into the engine that does not pass through the carburetor throat dilutes the mixture. So, even if the petcock is on "Prime" and fuel is being delivered to the carburetor, the mixture the engine sees will be very lean. As an aside, as engine load and speed increase, the pressure in the intake manifold increases and the air drawn in through the open vacuum port decreases both in absolute quantity and percentage of the whole, and the leaning effect eventually becomes insignificant.

[alantf]

So how is it, that if the vacuum pipe is cracked, and the engine won't start, switching to prime (which doesn't need vacuum) will let the engine start, and run o.k.? There's still the problem you mention, with extra air going to the carb through the cracked pipe, but the bike runs fine. :??:

[JohnC]

Pull the hose off and see if it will run fine then. Maybe there is a restriction in the vacuum port that limits the amount of air drawn in. A restriction wouldn't significantly affect the operation of the petcock since there's no flow involved.

Such a setup would only be suitable for a single cylinder bike as multi-cylinder bikes use the same ports for carb synchronization and they are necessarily unrestricted.

[QUICKSTRONG]

Pull the hose off and see if it will run fine then. Maybe there is a restriction in the vacuum port that limits the amount of air drawn in. A restriction wouldn't significantly affect the operation of the petcock since there's no flow involved.

Such a setup would only be suitable for a single cylinder bike as multi-cylinder bikes use the same ports for carb synchronization and they are necessarily unrestricted.
tonight I took the carb off again there is gas in the floatbowl but the rest of the carb seems bone dry???? does anyone know what is going on here?? no wonder it wont start

[jonathan180iq]

Good vacuum to draw fuel through the system and clean ports within the carb are necessary to get this thing running. If it sat for so many years, I would replace the vacuum hoses anyway. There are only 3 or 4, IIRC. Get some new hose from the auto parts store and go to town.

You're probably going to have to disassemble the carb to clean all the other inner ports.

There is no reason to rush carb work. Since this is the only method the bike has of delivering fuel and air into your engine, then you need to just go ahead and do it right the first time.

(Couple of mini-thoughts. You aren't trying to start the bike with the kickstand down are you? You're using choke? You will always have to use choke on the GZ. Did you ever test for spark?)

[QUICKSTRONG]

Good vacuum to draw fuel through the system and clean ports within the carb are necessary to get this thing running. If it sat for so many years, I would replace the vacuum hoses anyway. There are only 3 or 4, IIRC. Get some new hose from the auto parts store and go to town.

You're probably going to have to disassemble the carb to clean all the other inner ports.

There is no reason to rush carb work. Since this is the only method the bike has of delivering fuel and air into your engine, then you need to just go ahead and do it right the first time.

(Couple of mini-thoughts. You aren't trying to start the bike with the kickstand down are you? You're using choke? You will always have to use choke on the GZ. Did you ever test for spark?)

Yes it has plenty of spark However, I am trying to start the bike with the kickstand down! I never thought about that, is the kickstand some kind of safety switch?

[blaine]

Good vacuum to draw fuel through the system and clean ports within the carb are necessary to get this thing running. If it sat for so many years, I would replace the vacuum hoses anyway. There are only 3 or 4, IIRC. Get some new hose from the auto parts store and go to town.

You're probably going to have to disassemble the carb to clean all the other inner ports.

There is no reason to rush carb work. Since this is the only method the bike has of delivering fuel and air into your engine, then you need to just go ahead and do it right the first time.

(Couple of mini-thoughts. You aren't trying to start the bike with the kickstand down are you? You're using choke? You will always have to use choke on the GZ. Did you ever test for spark?)[/quote
Yes it has plenty of spark However, I am trying to start the bike with the kickstand down! I never thought about that, is the kickstand some kind of safety switch?


When working properly the bike will stall if you try to put it in gear with the stand down.
;) :)

[alantf]

There's no problem with starting the bike with the side stand down. So long as it's in neutral. The safety switch only kicks in (to turn the engine off) if you try to put it in gear with the stand down. This is a safety feature, so you can't ride off with the stand down.:2tup:

[QUICKSTRONG]

There's no problem with starting the bike with the side stand down. So long as it's in neutral. The safety switch only kicks in (to turn the engine off) if you try to put it in gear with the stand down. This is a safety feature, so you can't ride off with the stand down.:2tup:
I cleaned the a few days ago but just to make sure the carb is not the problem i took the carb to local shop and had them clean it they took it apart and dipped it. put it on the bike still will not start even with the petcock on prime???
So I decided o fix the leaky valve cover so I removed it and now I need to know how to put it back on. what is the little black rubber circle on he side for? What is the purpose of this. What holds it in place? just the pressure from the cover? when I put the valve cover back on do i need to use any rtv or is there a gasket that should be there? All that was there was some residue from what looked like old rtv gasket maker no gasket.
What should I be looking for as far as problems while I have this off. How much more work is it to replace the head gasket as long as I am this far? Any help is appreciated this is my first time with all of this so I am learning as I go.
Thanks

[mrlmd1]

You also must pull in the clutch to start the bike - another safety switch.

[QUICKSTRONG]

You also must pull in the clutch to start the bike - another safety switch.
Can someone give me directions on adjusting the lifters? maybe it is not starting because the lifters need adjusting??? :??: what are the specs for the intake and exhaust and how do I find TDC???
thanks

[JohnC]

There's a thread in the troubleshooting forum right now.

Lifters (actually, there aren't lifters in this engine, what you are adjusting is valve clearance) won't keep an engine from starting just because it has been sitting. The clearance won't change from sitting, so if it ran before clearance isn't your problem. If you have a good spark than you can pretty much bet it's clogged carburetor passages.

[QUICKSTRONG]

There's a thread in the troubleshooting forum right now.

Lifters (actually, there aren't lifters in this engine, what you are adjusting is valve clearance) won't keep an engine from starting just because it has been sitting. The clearance won't change from sitting, so if it ran before clearance isn't your problem. If you have a good spark than you can pretty much bet it's clogged carburetor passages.
Does anyone know a good mechanic in Lakeland Florida? I am willing to just hire someone who knows what they are doing.

[jonathan180iq]

We had a couple of knowledgeable members down in your neck of the woods are different times, but attendance here is fleeting sometimes.

It's such a simple bike, just take it into the Suzuki place if you don't want to do it on your own.

Also, download this:
viewtopic.php?f=3&t=27 (http://www.gz250bike.com/forum/viewtopic.php?f=3&t=27)

troubl-shooting guides and everything else you will ever need to know

[QUICKSTRONG]

There's a thread in the troubleshooting forum right now.

Lifters (actually, there aren't lifters in this engine, what you are adjusting is valve clearance) won't keep an engine from starting just because it has been sitting. The clearance won't change from sitting, so if it ran before clearance isn't your problem. If you have a good spark than you can pretty much bet it's clogged carburetor passages.
Does anyone know a good mechanic in Lakeland Florida? I am willing to just hire someone who knows what they are doing.

OK I had a mechanic stop by today, he showed how to do a compression test and leak test. Bottom line there is little to know compression. Without taking the motor apart he said I will need to at least breakdown and rebuild the top end of the motor.
So I need some help here, what parts will I need to rebuild the top end of the motor, and is there a link with directions?
Has anyone on here rebuilt their engine? what was the cost and how hard is it? Or should I look for a salvaged engine? Thanks for any help.

[raul10141964]

before you remobe the head check if you have some play on the valves.
If you do not fill any play adjust the valves

[JohnC]

You may have just stuck rings. I agree, though, do a rough check on the valves first, then squirt a little oil in the plug hole and recheck the compression. If it comes up then you may just have stuck rings or maybe a lot of rust in the bore. Pull it apart before you start ordering parts!

[jonathan180iq]

Agreed. There are several members who dived in head first to a complete tear-down only to later discover that it was not necessary. Take it to someone you can trust if you don't want to do it yourself. Bike shops would love to replace the top end or re-ring the bike for you... but that's $$ that probably doesn't need to be spent.

Test - do not guess.