Problems accelerating | GTAMotorcycle.com

Problems accelerating

C

crackerjack

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Hey everyone, new rider here. I just recently started riding a 1981 Honda gl500 Silverwing. This bike was very well maintained by my father-in-law, so it's in pretty good shape, even though its old. I've only put about 140km on it and it's been running great. Until last night. I went to go for a ride and it started up great as usual. I was driving in town so I made a few stops at lights and intersection for about 10 minutes. Then all of a sudden, after a stop, the bike stalled while I was leaving an intersection. I fired it right back up and made it through the intersection, but I really had to ride the clutch. As soon as I wanted to let the clutch out, it started sputtering. I was finally able to get it going, but had trouble getting it up to 50km/hour, even in third or fourth gear. I slowly made my way back home and parked it. Any ideas on what could be the problem? I've only put 110km on it since I filled it up last. I can see gas when I take the cap off, so i'm sure thats not the problem.
 
Right off the hop I'd look at a new fuel filter.
 
Don't want to offend you with this, but since you've only ridden about 140km...

Did it happen regularly? Are you sure you had it down to first gear?

I haven't been riding that long either, but when I first started I would occasionally lose track of what gear I was in.
 
Hard to diagnose without hearing / seeing it, but it sounds like you might have only be running on one cylinder. This could be due to a spark issue with a plug not firing or one of the carbs not feeding the cylinder fuel. Perhaps if your father in law is very familiar with the bike he can help you diagnose it, but this is where I would start.
 
assuming you were in 1st gear...

you could have a charging system/battery issue
fuel filter clogged
cracked fuel line
stuck float
time for carb rebuild kit
lack of air

i hate to say it, but this is why i buy fuel injected bikes... carbs are like a art...ive managed to fix a few with just luck...but they need to be properly tuned by someone who has done it before..
 
So I just went out and played around with my bike. It started up great as usual, but even with the choke, the rpm's only went up to 2. After i took the choke off, the rpm's in neutral were only going up to 1. I then put the bike into first gear and the rpm's dropped between 0-1. Eventually while in first gear, the bike stalled. Does this sound like a big problem? Thanks guys(and girls), I really appreciate any info and advice you guys can give me.
 
EaZ8 said:
assuming you were in 1st gear...

you could have a charging system/battery issue
fuel filter clogged
cracked fuel line
stuck float
time for carb rebuild kit
lack of air

i hate to say it, but this is why i buy fuel injected bikes... carbs are like a art...ive managed to fix a few with just luck...but they need to be properly tuned by someone who has done it before..
Click to expand...

Wouldn't a stuck float or cracked fuel line show leaking fuel?
Touch the exhaust pipes, if one is cold, you're running on one cylinder. Could be a coil.
Run it with the gas cap open, might be a plugged vent.
Carbs are easy to work on. That's why I only buy carbed bikes.:p
 
CJ
Don't let the likes of Eaz8 and their lack of knowledge scare you. Inreb is on the right track. Touching the pipes is always my first check to make sure both or in my case all four cylindrs are firing.

You only need 3 things - Fuel spark and compression. If it was running good recently compression should not be an issue. You can trace fuel flow easily by pulling the fuel line after the petcock. If you get fuel there try opening a float bowl drain.

Pull the plugs. Are they wet? Gunked up? It's amazing what 6$ worth of new plugs can cure. Turn it over while you ground them out (don't do this with a bare hand, lay them on a fin or other metal). You need to see good blue spark.
 
dirtbag said:
CJ
Don't let the likes of Eaz8 and their lack of knowledge scare you. Inreb is on the right track. Touching the pipes is always my first check to make sure both or in my case all four cylindrs are firing.

You only need 3 things - Fuel spark and compression. If it was running good recently compression should not be an issue. You can trace fuel flow easily by pulling the fuel line after the petcock. If you get fuel there try opening a float bowl drain.

Pull the plugs. Are they wet? Gunked up? It's amazing what 6$ worth of new plugs can cure. Turn it over while you ground them out (don't do this with a bare hand, lay them on a fin or other metal). You need to see good blue spark.
Click to expand...

My father-in-law is pretty handy with bikes. He agrees with you that it's probably the plugs. I'm going to buy new plugs tomorrow and he's going to stop by in the next few days and replace them. Hopefully that's all I have to do!
 
inreb said:
Wouldn't a stuck float or cracked fuel line show leaking fuel?
Touch the exhaust pipes, if one is cold, you're running on one cylinder. Could be a coil.
Run it with the gas cap open, might be a plugged vent.
Carbs are easy to work on. That's why I only buy carbed bikes.:p
Click to expand...
Stuck float wouldnt cause a leak.
cracking fuel line ($10 part) may only leak when its trying to draw fuel, which means it could evaporate before you notice it. Ive had this happen on a buddy's bike (and a chainsaw)
also, check your tank bike potential Gunk floating around in it. It can restrict fuel flow...also happend on a buddys bike.
If its firing on only 1 cyl you would know....that actually also happened on the same buddys bike... his plug wire has come loose and wasnt making a connection.

Not trying to scare you but theres a lot of small things to check
 
Look for any loose hoses or something else that may cause a vacuum leak.
 
Sounds like water in the tank. DId you fill up after winter storage?
But yeah - either spark or fuel flow.
 
EaZ8 said:
Stuck float wouldnt cause a leak.
cracking fuel line ($10 part) may only leak when its trying to draw fuel, which means it could evaporate before you notice it. Ive had this happen on a buddy's bike (and a chainsaw)
also, check your tank bike potential Gunk floating around in it. It can restrict fuel flow...also happend on a buddys bike.
If its firing on only 1 cyl you would know....that actually also happened on the same buddys bike... his plug wire has come loose and wasnt making a connection.

Not trying to scare you but theres a lot of small things to check
Click to expand...

A stuck float would cause fuel to pour out of the overflow if it was stuck open/down.
 
Hey guys, it was the spark plugs for sure. We had a lot of rain here in 2 days. The wind had blown the cover off of my bike, and the rain got into it. I took the first spark plug out and there was water inside. I dried it out, put in new plugs, and it fired up. Thanks everyone!
 
dricked said:
A stuck float would cause fuel to pour out of the overflow if it was stuck open/down.
Click to expand...
i guess i stand corrected.
ive had a few all gummed up and stuck but it didnt leak fuel....but as i said, my knowledge of carbs is limited. i usually luck out and get it working.

i still think you should have someone qualified to tune the carb so you have it running properly. find a shop or private mechanic that knows what they are doing.
 
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