Power Loss

[Sarris]

I'd suggest a new spark plug, a new air filter, and some Berryman's or Seafoam in a fresh tank of gas (discard the old gas). Then take it out and run the crap out of it. Try to run as much gas (with the additive in the mfgr's suggested amount!) through it as possible. GeeZers are very susceptible to a gummed up carb after sitting for a while. It really doesn't sound like an electrical issue, just more of a dirty carb issue.

Good luck.

[Clockwork]

I looked at the plug and it looks fine. I replaced it anyways. The Bike had a new air filter in the Spring, as well as a full carb clean, so I hope it isn't those things.

One other development happened today, I was driving and thanks to little traffic I was able to keep a constant speed for quite some time (in 3rd gear). The revs were constant and in the high range (which for my speed I expected in 3rd). All of a sudden the problem happened again, only this time, once I stopped (at a stoplight) and started again the problem had disappeared. The engine had no time to cool down, which suggests to me it wasn't a heat problem. Also, driving at higher revs for extended periods is consistent with the problem. Only before it was necessary because I was driving at highway speeds.

Does this shed some light on the problem? I am almost inclined to think it might be a transmission problem. Could the clutch be slipping? It doesn't happen every time I rev the bike up, only after it has been at high revs for an extended period.

Thoughts?

P.S. Thanks for your help so far guys, you have all been great.

[alanmcorcoran]

I went back and read your original description of the problem, focusing on the "sound." I thought you might have a hairline crack in your exhaust or head or something involved in the compression but, since I really don't know much about bike mechanics, I kept my thoughts to myself. Is this sound still happening? Have you tried to isolate where it's coming from? Felt around for rushing air where there shouldn't be any? Can you record it with your phone or camera? It seems to be the unique aspect of your problem.

[Easy Rider]

Originally Posted by Clockwork

I am almost inclined to think it might be a transmission problem. Could the clutch be slipping? It doesn't happen every time I rev the bike up, only after it has been at high revs for an extended period.

I would say absolutely not.....but knowing how sometimes the written description doesn't do justice to the real problem.....I guess we can't rule anything out.

It sounds to me like a fuel delivery problem.....or some hidden "gunk" in the carb.

What you describe sounds very much like a tank vent problem or the float in the carb being set too low. You can check the tank vent by opening the gas cap when it is failing.

Since it quickly corrected itself this time, a speck of dirt might have come loose in the carb.

At this point, I'd suggest some carb cleaner in the gas......unless you can leave it at the dealer for a few days with a full explanation of the problem.

Have you taken the air filter out and LOOKED back into the air box.....on the off chance that there is a leaf or piece of plastic floating around in there ??

Also just remembered that an intermittant side stand safety switch can cause the problem you are describing too. Have a look at it to be sure it isn't loose.

These guessed are getting pretty desperate.

[blaine]

Originally Posted by Easy Rider

It sounds to me like a fuel delivery problem.....or some hidden "gunk" in the carb.

What you describe sounds very much like a tank vent problem or the float in the carb being set too low. You can check the tank vent by opening the gas cap when it is failing.

Since it quickly corrected itself this time, a speck of dirt might have come loose in the carb.

It definitely sounds like a fuel delivery problem.
I think you may have a blocked screen in the petcock or possibly a collapsed fuel line preventing fuel from filling the float bowel when the bike is reving.When you come back to idle or lower revs,bike is getting enough fuel to work properly.

:??: :2tup:

[Clockwork]

Originally Posted by alanmcorcoran

Is this sound still happening? Have you tried to isolate where it's coming from? Felt around for rushing air where there shouldn't be any? Can you record it with your phone or camera? It seems to be the unique aspect of your problem.

Yes the sound is starts just before the power loss. The problem is that the sound only occurs when the revs are high and the bike is moving. So I can't really feel around until after the fact and this includes listening for problems. What I think I will do is try and get the problem started and keep the sound occurring while I slow down (high revs in Neutral maybe). Once I come to a stop hopefully I can have a poke around.

Originally Posted by Easy Rider

It sounds to me like a fuel delivery problem.....or some hidden "gunk" in the carb.

What you describe sounds very much like a tank vent problem or the float in the carb being set too low. You can check the tank vent by opening the gas cap when it is failing.

Since it quickly corrected itself this time, a speck of dirt might have come loose in the carb.

At this point, I'd suggest some carb cleaner in the gas......unless you can leave it at the dealer for a few days with a full explanation of the problem.

Have you taken the air filter out and LOOKED back into the air box.....on the off chance that there is a leaf or piece of plastic floating around in there ??

Also just remembered that an intermittant side stand safety switch can cause the problem you are describing too. Have a look at it to be sure it isn't loose.

These guessed are getting pretty desperate.

If I can get the problem to occur I will try opening the gas cap and see if that corrects itself. What do you suggest for a brand of in-gas carb cleaner? I have never used any before. I will also look inside the airbox. I didn't notice anything when I checked the filter, but I didn't look closely. I will check this out. On a side note, does the air filter always smell like gas? I will also have a look at the safety switch.

Originally Posted by blaine

It definitely sounds like a fuel delivery problem.
I think you may have a blocked screen in the petcock or possibly a collapsed fuel line preventing fuel from filling the float bowel when the bike is reving.When you come back to idle or lower revs,bike is getting enough fuel to work properly.

Is there a good way to check the petcock? When I do the other checks suggested I will have a look at those fuel lines and see what condition they are in.

Thanks again for your help guys, this is such a weird problem.

[blaine]

Originally Posted by Clockwork

Is there a good way to check the petcock? When I do the other checks suggested I will have a look at those fuel lines and see what condition they are in.

Thanks again for your help guys, this is such a weird problem.

Berrymans B-12 or Sea-foam are both good cleaners.About the easiest way to check your petcock and fuel line is to disconnect fuel line at carb,turn petcock to prime,and check to see if you have good flow.It is normal for filter to have some smell on it.The main thing is that it's clean & dry.

[Easy Rider]

Originally Posted by blaine

Berrymans B-12 or Sea-foam are both good cleaners.About the easiest way to check your petcock and fuel line is to disconnect fuel line at carb,turn petcock to prime,and check to see if you have good flow.It is normal for filter to have some smell on it.The main thing is that it's clean & dry.

:plus1:

Seafoam is OK for routine use and as a stabilizer for storage but B12 is a better cleaner for when there actually is a problem.

And one more thought: Drain the float bowl. Might be some "water" in the bottom, coming into play when there is a high fuel demand.

Have we mentioned draining the air box tube ??

The noise you are hearing might just be from a lack of fuel at high rev's. or a sucking sound from a vacume in the tank. I can't see an actual leak closing up that quickly.

[Palaka]

I was wandering if you have checked the the main wire bundle running under the fuel tank?
I had a problem I thought was from riding for long periods of time or just a dirty carb. The engine would just die out, but I would be able to start it up again most of the time. The last time I had it happened it took about 20-30 min to get it to start up.
I followed all the suggestions I found on this site including b12, wd-40, drain airbox, spark plug and anything else. After taking the carb off to clean it and put it back in the problem changed to when I turned the handle bars it would die out. After a close inspection of the wiring I found that the positive wire going from the coil to the ignition unit had melted down to a bare spot that was grounding out on the case causing it to die. The sound you hear could be the sound of the wires sparking on the metal. I ended up repairing the wire and replacing all the electrical tape wrappings with some good heat shrink and securing the wiring so it will keep its clearance from the engine.
Since I have repaired the wire and secured them properly I have had no problems and my bike runs great. I hope this helps a little. I know you said your engine wouldn't die completely but it might help.
Ride Safe

[Viirin]

You can remove the petcock easily once the tank is off - if you haven't already done this just take off the seat and there's two bolts at the back of it - when you take the tank off keep it upright until you drain it or you'll run your pants too - once you drain the tank the petcock can be easily removed with a couple of spanners but be careful not to loose the small rubber seal between it and the tank! There should be two plastic pipes sticking out of it - one for reserve and one for main - if one of these is missing you can be pretty sure its a dirty carb - while the petcock is off you can also make sure there isn't a built up of gunk in your MAIN/RES/PRI switch - after that just make sure that fuel can flow through the metal pipes of the petcock and the rubber pipe connecting the fuel tank to the petcock.

A kink in that pipe stopping fuel flow had me very confused for about half and hour once

As i've been told many times - once something goes wrong all we can do is go through a checklist until we find the problem so don't rule out anything until your sure!
- best of luck with it -

Vii