Bike will idle but won't accept any throttle | GTAMotorcycle.com

Bike will idle but won't accept any throttle

thedude

Well-known member
Hey all,

So I'll give the full story as to how this all went down for clarity reasons. I took my '99 Rebel 250 out to give it a wash today. While I was washing I noticed that my petcock was switched to reserve (I brought it home a few days ago and had switche over right around the corner from my house and forgotten about it) the closest source of gas that was available to me was the Jerry Can in my garage, so I finished up the wash and started to ride home. About 1/2 block from my house it died out on me. I pushed it (shamefully) home and put it in the garage. I returned about 45min later to take it out, gasse it up with the J-Can and started it up. It idles fine, but whenever I give it any throttle it sputter and dies out. What can I do about this.

For some backstory at the end of last season I had a problem with the bike refusing to start. I replaced the sparks and it started running again, although it was a little rough. It has been running pretty good for the last few weeks up until now. I appreciate any help that you guys could offer. Thanks!
 
Drain the gas, drop the floatbowl (rebel 250 is a single?) off the carb and pull the jets out and give it a good cleaning. Sounds like a clogged main jet.

Probably bad gas and particulate matter in the gastank.

Allan
 
^ +1

While you are at it, install an inline fuel filter to prevent those particles from gettin in the carbs again.

http://www.youtube.com/watch?v=iiK3GKWtsiE

While you have it apart

- inspect and clean the air filter
- inspect fuel hoses and manifolds for cracks/leaks

And remember... Have fun! :)
 
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Thanks or all the info guys, I'll give those a shot eithe tomorrow or Monday, gotta find the time. Any idea where I can get an inline fuel filter for a rebel, or are there universal options?U
 
Make sure to get a filter that fits a 1/4" fuel hose.

Where abouts are you located?

Flying Squirrel
http://www.fsmotorcycle.com/fuel-c-966.html

Flying Squirrel Motorcycle
388 Carlaw Ave #102D
Toronto, Ontario M4M 2T4
416.889.8769

or

Royal Distributing (Guelph, Innisfil, Whitby, Sudbury)
http://www.royaldistributing.com/ma...iew=book&id=14&Itemid=458&firstPageNumber=206

or Canadian Tire, Home Depot even
Hahaha, up until 3 months ago I lived around the corner from flying squiril motorcycle and didn't even know it was there. I'm near dufferin/bloor now but I'm in the east end fairly often, I'll check it out next time I'm nearby. Thanks bud
 
An inline filter can cause more problems than it is worth...I would say don't bother.
Do everything else mentioned and rinse the tank a bit with fresh gas to get out any remaining particles.

The filter sock on the top side of the petcock should stop anything that would bother the carbs, check and make sure it is still in place and working well, no holes etc.
 
An inline filter can cause more problems than it is worth...I would say don't bother.

As long as it is replaced regularly it should not cause problems. Can you explain why you think it would?
 
So I pulled out the carb today and have it a cleaning, but it didn't solve the problem. I'm getting some pretty thick looking exhaust now, and it sputters quite a bit when giving it any throttle. There was a lot of gas inside the carb when I pulled it off, each section I opened drained a fair amount. Any ideas?
 
You need to unscrew your jets and soak/blow them out.

If you didn't take your carb off, you didn't clean it properly.

Also check float bowl and needle valve/seat for height.

Allan
 
I let it run for 5 to 10 min with petcock on reserve. I did take the carb right off the bike, but paid more attention to the actually body of the carbourator instead of the needles, I'll give it another shot and let them soak this time. What is the best way to measure the float bowl and needle valve/ seat height?
 
How long did you let it run?
What position is your petcock in? off, on or reserve?


Did you let the carbs sit in carb cleaner and throughly clean the little holes in the jets?

http://www.youtube.com/watch?v=RIa23_0Hn9I
When I took it off the bike my carb looked as clean as the one in the video did after the cleaning, aside from the gas that had pooled inside.
 
^ did you check the air filter and air box when you had it apart?

I did take the carb right off the bike, but paid more attention to the actually body of the carburator instead of the needles, I'll give it another shot and let them soak this time.

When you took the carbs apart, did you ensure to count the number of turns it takes for the Air/Fuel mixture (pilot) screw to go all the way IN then remove it completely. Reinstalling the same as before you removed it? If not, the manual below has the instructions for setting it correctly (Section 5-12).

Did you take out the jets and clean them extensively? Clean the small holes on the jets. Preferably with an air compressor. Or with a thin wire (Guitar E String). be sure to work gently if using wire!

What is the best way to measure the float bowl and needle valve/ seat height?

I believe this is the manual for your Rebel 250 (CMX 250). It contains the specifications for the float level (Section 5-8 ). According to the manual Float level is 18.5 mm (0.73 in). To measure the float level you can use the Honda Float Level Guage, Part # 07401-0010000. The float cannot be adjusted. Replace the float assembly if the float level is out of specification.
Here is a ghetto tool to measure the float level on the carb (Credit card cut out)

Manual for Honda CMX 250 (Rebel 250)
http://199.91.153.87/qtpqbzy6wsgg/iijug9mzboxvabx/Honda+CMX250+Rebel+250+Service+Repair+Manual.pdf

However, if you had cleaned everything (including the jets) and put it back together properly, ensuring not to bend or break parts, and ensuring it is operating as it should (float can be moved up and down with your finger freely, etc), then it should at least be running the same if not better than before you removed the carbs.
 
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As long as it is replaced regularly it should not cause problems. Can you explain why you think it would?

They restrict flow, particularly in a bike with a gravity-only feed. They are fine on bikes with electric pumps, but not on old bikes like mine.
I tried one on my bike back when I didn't know better...all it takes is an air bubble in the filter and the bike won't even start.

Sounds like his slow/pilot jet is plugged since it is 99% responsible for fueling at idle, or there just isn't fuel getting to it.

His float height may have changed but...if it was running... Usually if they sink they cause the overflow to piss gas...so I doubt that too now that I think about it. He could just pop off the cover to see if there is fuel in there and what sort of height.

The biggest culprit is him using old gas..it is likely much older than he remembers and isn't good for much except cleaning parts now.

I'd go back to the earlier suggestion...drain gas, remove petcock. Flush with new gas from a clean container. Rebels have a small screen in the petcock iirc from mine 25 years ago...clean that too.
 
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^ did you check the air filter and air box when you had it apart?



When you took the carbs apart, did you ensure to count the number of turns it takes for the Air/Fuel mixture (pilot) screw to go all the way IN then remove it completely. Reinstalling the same as before you removed it? If not, the manual below has the instructions for setting it correctly (Section 5-12).

Did you take out the jets and clean them extensively? Clean the small holes on the jets. Preferably with an air compressor. Or with a thin wire (Guitar E String). be sure to work gently if using wire!



I believe this is the manual for your Rebel 250 (CMX 250). It contains the specifications for the float level (Section 5-8 ). According to the manual Float level is 18.5 mm (0.73 in). To measure the float level you can use the Honda Float Level Guage, Part # 07401-0010000. The float cannot be adjusted. Replace the float assembly if the float level is out of specification.
Here is a ghetto tool to measure the float level on the carb (Credit card cut out)

Manual for Honda CMX 250 (Rebel 250)
http://199.91.153.87/qtpqbzy6wsgg/iijug9mzboxvabx/Honda+CMX250+Rebel+250+Service+Repair+Manual.pdf

However, if you had cleaned everything (including the jets) and put it back together properly, ensuring not to bend or break parts, and ensuring it is operating as it should (float can be moved up and down with your finger freely, etc), then it should at least be running the same if not better than before you removed the carbs.
Thanks again for all the help guys. Aside from measuring the float level I've done everything you have mentioned. The airfield and box looked ok, I blew it out with some compressed air just to be sure. I put the pilot screw back to factory recommendation as per my service manual and ran some fresh gas through it. It started up ok but kept stalling when I gave it throttle. I delicately adjusted the pilot screw by ear (don't have access to a tach), and it stopped stalling when I reved i, but was backfiring a littlet. Havn't had time to put everything back on (mount the tank and seats) but when I do I'll take her for a spin and let you guys know how it worked out. Thanks again for all the help.
 
all it takes is an air bubble in the filter and the bike won't even start.

Sounds like his slow/pilot jet is plugged since it is 99% responsible for fueling at idle, or there just isn't fuel getting to it.

I would much prefer to swap out a $3 fuel filter than disassemble the carbs to clean out the jets because some crap from the tank got in there.

Just make sure to get a see through one. This way you can see what's going on easily (dirty, no fuel, etc).
Be sure to get a filter for a gravity-fed fuel system. Not all inline filters are ok for gravity-fed fuel systems!
 

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