Need throttle to start up bike

[7653]

FACTS:
My 2002 Suzuki GZ 250 needs to throttle to start up.
The carburetor was already recently cleaned at a service center.
The battery is new.
It was working fine before the a three-day weekend in which I did not use the bike.
(Note: when I first got the bike I had to keep throttle on at stops to keep it from stalling. After a few weeks of use I no longer had this problem but now it seems to have returned and with the additional problem of having to use throttle to start the bike up.)
I have tried adjusting the idle speed but I am not sure which way to adjust the little white knob and I don't want to turn it too much for fear I might screw it up.

DETAILS:
When I start my bike I give it max choke and have to be turning the throttle prior to pressing the starter button in order to get my bike to start. This start-up issue still persists even if I have ridden the bike for an hour and turn it off and try to start it up again. The bike has a strong gasoline smell when I try to start it up. It also sometimes has a lot of gulp gulp gulp sounds.

I also need to maintain throttle on my bike when I stop, if not the bike stalls. Sometimes after a long period of use I can remove throttle at stops for a good amount of seconds. But even then, if I leave the bike stopped for too long without throttle, it stalls.

ANY IDEAS before I give up trying to troubleshoot on my own and drive the bike to a service center?




My bike has an issue similar to:
viewtopic.php?f=7&t=5194 (http://www.gz250bike.com/forum/viewtopic.php?f=7&t=5194) -- Gas contaminated with oil.
http://forum.motorcycle-usa.com/default ... 8&m=520984 (http://forum.motorcycle-usa.com/default.aspx?f=18&m=520984)
http://www.youtube.com/watch?v=OUE30c_8s8U -- The guy from this video said the head and exhaust header gaskets were leaking, contributing to the problem.

[alantf]

I have tried adjusting the idle speed but I am not sure which way to adjust the little white knob and I don't want to turn it too much for fear I might screw it up

Imagine that you're screwing in a screw (clockwise). This increases the speed. When the engine is hot, with the choke off, if you don't notice any increase of speed when you screw it in, then something is really amiss. You'll not do any harm if you screw it in a couple of turns. If the engine doesn't speed up, back it off to its original position (no need to be absolutely spot on) & then you'll probably find that the problem is that the carb needs cleaning. Have you run any carb cleaner through lately? The carb seems to be the weak feature on an otherwise good bike. :2tup:

[Gz Rider]

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[Meme]

A little bit of throttle to get it started when it is cold out is normal for my bike. These bikes need the idle set pretty high, I've read 1400 RPMs, to stay running. If adjusting the idle screw doesn't fix your problem, my guess is your carb is dirty. Various in-the-tank carb cleaners may work, but if a passage is totally plugged up they probably won't work, and it needs to be disassembled and thoroughly cleaned.

You don't say if the carb was cleaned since this problem started (or came back). It sounds a little like the problem I had when my carb had a plugged up starting circuit.

[7653]

alantf: Thanks alantf. I turned my idle half-a-circle clockwise and it improved the situation somewhat. I'm going to try the carburetor gas tank fluid when I get a chance to stop by Kragen's. (Seafoam?)

Gz Rider: Good to hear from you again too, Gz Rider! I was actually thinking the same thing about the idle switch before you helped clarify the issue. I was just about to take a picture of the idle switch from the top and bottom angle, draw counterclockwise and clockwise arrows in the jpg picture, then post it here and ask: which clockwise? viewed from bottom or top? I still might.

Meme:
A little bit of throttle to get it started when it is cold out is normal for my bike. These bikes need the idle set pretty high, I've read 1400 RPMs, to stay running. If adjusting the idle screw doesn't fix your problem, my guess is your carb is dirty. Various in-the-tank carb cleaners may work, but if a passage is totally plugged up they probably won't work, and it needs to be disassembled and thoroughly cleaned.

You don't say if the carb was cleaned since this problem started (or came back). It sounds a little like the problem I had when my carb had a plugged up starting circuit.

I did not get the carburetor cleaned when this problem came back and/or started. I figured since I just got it cleaned in October or so that it couldn't get clogged back up so soon. I guess I may be wrong then.

Conclusion: Despite fiddling with the idle switch, I still need throttle to fire up the bike. The idle fiddling did improve/help lessen stalling at stops. Fiddling with the idle also helped me get off the throttle sooner while warming/starting up the bike with the choke.

I'll try fiddling with the idle for some more rpm and get some carburetor cleaner to try to avoid a trip to the service center. I read from these forums that Seafoam is good? Any other suggested brands?

[blaine]

SeaFoam & Chemtool Berrymans b-12 are two of the best on the market.
:cool:

[Rookie Rider]

I put STABIL in the tank to winterize it, but the other day was so nice out and i rode it. It felt so smooth from the stabil i loved the way it felt. Got home and i put another tablespoon of it in the gas tank.

[Gz Rider]

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[Rookie Rider]

Yes, i topped it off with gas.

[Gz Rider]

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[7653]

Actions:
-Turned the idle knob .75 turn clockwise. After the idle speed knob was adjusted when there is no throttle at all the bike moves about 5-6 MPH. (I don't have a tachometer so I am describing the RPM of my bike through how fast/MPH it moves without any throttle at all instead.)
-Put one-fifth of a can of Seafoam into the gas tank and rode bike for about 40 miles total since then

Results:
-Bike does not stall during stops anymore. Bike idle is louder. -- probably due to increased idle speed
-Bike seems to run a little bit smoother now -- due to Seafoam or placebo effect?

Lack of Results:
-In order to fire up the bike I still need to put it on full choke and throttle before I even press the starter button
-When it is on full choke and throttle and I press the starter button I still sometimes have to hold the starter button for the length of a several "tuh tuh tuhs" and when I get off the starter button the bike has to quietly make a few "jug jug jug jug" sounds while my bike is on full throttle & choke before it will sound off with a loud RRRRREEEEVVVV.

Any ideas on what else can be done to fix the latter? What is the problem? Or should I just bring the bike to a mechanic?

[alantf]

Sounds about right. Keep using the carb cleaner for the next 3 or 4 tankfuls & see if you get any further improvements. What do you mean when you say that idle speed is 5 or 6 MPH. Idle speed is measured in revs per minute (RPM)? Idle speed with the engine thoroughly warm, & the choke off, should be around 1400 to 1500 RPM. I wonder if the problem, all along, has been that you don't understand what "idle speed" means? Can you give us a run down as to what you understand by "idle speed" so we can see if there's been any misunderstanding?

BTW, 1400 to 1500 RPM means that the bike should sound more than 50% faster than the car, at idle. A car idles at around 860 RPM. :2tup:

[PimpS]

Is it possible to set up a rev meter to a gz? Is it worth of hassle? anyone has it?

[7653]

Sounds about right. Keep using the carb cleaner for the next 3 or 4 tankfuls & see if you get any further improvements. What do you mean when you say that idle speed is 5 or 6 MPH. Idle speed is measured in revs per minute (RPM)? Idle speed with the engine thoroughly warm, & the choke off, should be around 1400 to 1500 RPM. I wonder if the problem, all along, has been that you don't understand what "idle speed" means? Can you give us a run down as to what you understand by "idle speed" so we can see if there's been any misunderstanding?

BTW, 1400 to 1500 RPM means that the bike should sound more than 50% faster than the car, at idle. A car idles at around 860 RPM. :2tup:

I shall digress off topic for a while to answer your question, alantf. Hopefully, there won't be more posts asking this because I want to focus on my problem.

I do know what idle speed means. But since I don't have a tachometer to check the RPMs I have been measuring and paying attention to my idle speed through a different medium/method. In addition to paying attention to the sound of the bike, I have also been paying attention to the MPH of the bike when I do not give it any throttle at all as a means of sensing what the RPM of the bike is.

Before I increased the RPMs/turned the idle speed up/idle knob clockwise .75 -----> the MPH my bike would travel without throttle was 3-4 MPH.
After I increased the RPMs/turned the idle speed up/idle knob closewise .75 ------> the MPH my bike would travel without throttle is now 5-6 MPH.

So yes, I understand idle speed is NOT the speed the bike travels when it is doing nothing. I'm just mentioning that the bike now moves faster without throttle so that other posters have a means to see where my bike is at in terms of RPM, since I don't have an exact RPM to tell them where my bike is at.

Did my explanation make sense at all?

Now back to talking about my main question, so I can get my bike working properly!

[alantf]

Now back to talking about my main question, so I can get my bike working properly!

I thought that's what I had done! The bikes starting, so I said to run carb cleaner through for the next 3 or 4 tankfuls, & see what improvements you get. Next, forget all that nonsense of how fast the bike goes without throttle. LISTEN to the engine! Like I said, it's around 50% faster than your car idle. So - warm your bike up, make sure the choke's off, not in gear, and LISTEN to the engine. It's not rocket science! It should sound like a very fast idle - 50% faster than your car! If you can't grasp this concept, then I'd advise you to find someone who can LISTEN to your engine, and advise you. Notice that I keep highlighting LISTEN. That's the ONLY way you'll get it right without a tacho.
Phew, Hope you'll try this! :) :2tup:

[Gz Rider]

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[Gz Rider]

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[mrlmd1]

Proper idle speed in a warmed up engine is 1300 rpm.

[alantf]

Proper idle speed in a warmed up engine is 1300 rpm.

My handbook states 1200 to 1400, so 1300 is a good starting point to adjust it to what you're happy with. :)

[7653]

Thanks alantf, Mrlmd1, and Gz Rider.

I will go with alantf's suggestion of using Seafoam over the period of several tanks of gas and avoid going to the service center if possible. It could be possible they did a shoddy job on cleaning the carb. When I first got my bike back after they had cleaned it I had to keep throttle on my bike at stops to keep it from stalling (this stopped eventually and the bike would run like normal). The full throttle/choke and stall@stops issue returned after I did not ride the bike for four days. Could four days cause so much problems?

I'm just afraid if I don't get a quick fix though, there might be one crappy day when I can't start it when I'm trying to get back home or something.

I have been calculating the gas mileage on my bike:

The tank was full at 917.45 miles and when I reached 1068.8 miles I filled it back up with 2.182 gallons.

1068.8 minus 917.45 then divided by 2.182 equals 69.36 MPG.

The tank was full at 1068.8 miles and when I reached 1226.45 miles I filled it back up with 2.47 gallons.

1226.45 minus 1068.8 then divided by 2.47 equals 63.826MPG.

My current mileage is at around 13xx and I still have not filled up the gas since I adjusted the idle so I'm curious if the idle speed change will effect anything. Is my current MPG normal?

[alantf]

I get around 72 MPG (UK). which, I think, is around 60 MPG (US), but mine is nearly all town/short distance riding, usually stop/start in heavy traffic. :)

[Gz Rider]

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