Hello to all. My name is Mark. I ride a 02 Shadow Spirit 1100 and my son rides a 96 GS500. My sons bike has a problem and I hope someone here can point me in the right direction.
We got his bike used and not from a dealer. We had no warrenty and didn't notice the problem til the ride home. At about 7000 RPM the bike loses power and tries to die. If you downshift and get above 8000 it picks back up and runs to redline fine. When you shift up and go below 7000 it starts all over again. It seems to be worse when the bike is well warmed up. Is there a rev limiter going bad or what? Dealer here wants $100.00 just to start looking. Any ideas and/or if anyone has seen this and pretty much knows the problem does anyone have a parts bike I can get a part from? Thanks in advance for any help! Mark
Mine was doing that at around 4000 rpms... I put half a bottle of gum out carb cleaner in it and my problem went away.
Not to say it will work for you, just that it seemed to clear my bike up and might be worth a try.
Tried that. No help. I'm leaning towards the electrical parts but I could be wrong. If nothing else I'll try that again. Anyone else have any thoughts? Also let me say this. I've installed new plugs and a K&N air filter . Didn't help. It sounds like the ignition is just turned off then above 8000 it comes back alive. Thanks
We'll get you the answer (I think!) Someone recently got his problem solved... while looking for it, he managed to check out most every system on his bike! :lol: Took a while... But the GS isn't a difficult machine and we've got some immensely knowledgeable individuals around. I'm just not one of them :oops:
My thoughts? Play with the mixture screw on the carbs... although it might be a little too high in the rev range, you could have the bike at a bad air/fuel mixture and at mid revs, it could go into a particularly bad mixture and the bike tries to die.
I appreciate it. Let me add some more info. When cold the bike runs OK. It's only after it warms up the problem comes back. The last time I rode it, after it warmed up, I heard a "POP" then the dying started. It goes away when the bike cools down until it warms up again. My son says he hears this POP after the bike warms about half the time the other half it just dies. Thanks again for any help.
check your valve clearances.
The GS doesn't have a rev limiter, so that can't go wrong!
The fact that it runs OK cold would seem to indicate it is rich. That's a bit unusual with the GS. Does it have the problem at all throttle openings, ie is the problem there when you run through the lower gears at 1/2 throttle, or is it only at wide open throttle?
Checking the valve clearances would be good. While you are in there, it is probably worth pulling the float bowls off the carbs, and checking for debris, water, and general cleanliness. Cleaning the jets would be a good idea.
Is the fuel fresh? Might not hurt to drain the tank and put in fresh gas.
I doubt very much it is electrical. The carbs may have been monkeyed with or need cleaning.
I'm betting a carb cleaning, and making sure the jets are near the stock ones will fix it. 40 pilot jets, and 127.5 mains work well with a stock set-up. That is the stock jetiing for Canadian models. The US ones were leaned out for emmisions. Check there isn't a bunch of washers under the needle.
One time I had a similar problem, it turned to be a bad plug. I doubt that is your problem, but new plugs are cheap, so you might as well try and fit new ones.
Otherwise, what Kevin said, but first check that your air filter is clean.
KevinC... I thought 125 was stock mains for canadian bikes...
Other than all the rest these guys posted... here is my guess...
Tiny little rip in the diaphragm. Find which cylinder cuts out, then try swapping diaphragms and checking.
Also air filter clogged is a good thing to check. if the filter is dirty and its the stock paper one you can wash it in gas and dry it and re use it a time or 2. Before needing to replace it.
Cool.
Srinath.
My air filter is a bit grungy, but compressed air isn't blowing anything out... what do you do with the gas after you wash it? Maybe if you used kerosene (paraffin for you Brits) you could burn it in a camping lantern or stove.
Compressed air is nearly useless unness you blowing it out every 3-400 miles and you need to blow clean side to dirty side. Anyway I washed it in a milk gallon container, byt slicing off the top. Then the gas goes into my gas vat which I use to clean various stuff with. Also make sure you take only the top part (cleaner gas ) to clean other things with. The dirty part I just let it sit till it evaporates, and then wipe off the dirt and trash it.
Cool.
Srinath.
127.5 in the older Canadian GS's.
Let me introduce you all to my Dad (Mark H). He's the one that started this thread for me. If some of you don't know, my bike has a Cobra F1R slip-on and we just put in a K&N replacment filter about a month ago so it's not the air filter, as well as new plugs. It doesnt happen at a certain throttle postion, it happens between 6-8k. And it happens a pretty good bit. What happens is when I'm acclerating and ease back off and in maybe 4th gear running maybe 60mph, it seems like the engine just cuts off. I then shift up one and its fine, until i get to 6-8k. Then it starts all over.
Ifit happens at the same rpms, rather than at some throttle opening, I'd be more inclined to think that it's some electrical problem. Kerry wrote a great walk through diagnosing those gremlins in a past thread. You can find it if you do a search.
I think miket is talking about the old thread Narrowing down the problems to a broken bike (http://www.gstwins.com/forum/viewtopic.php?t=5500).
I didn't post the link right away because your symptoms seem to be different. But if you can duplicate your symptoms by revving the bike to the "problem RPM range" while it's sitting still, you might give the ohmmeter-based tests a shot. I just don't see how you can perform the tests, since the bike needs to be OFF when you do.... :(
Anyway, be patient as you read through the thread. I finally broke down and posted a checklist at the bottom of Page 2. One of these days I'll have to write up a straightforward article on this part of the electricals....
miket may also have been thinking about this more recent thread (http://www.gstwins.com/forum/viewtopic.php?t=6954).
OK 96GS I am certain now your issue is carburetion.
7K in top gear is bad but it will make 7K and more in 1-5... OK clearly it not eliectrical... cos 7K isn't the problem no matter what. Valves and others are OK too .. its not mechanical. Carburetion is load dependent and most carburetion issues only surface in 6th. I also believe you are hving the issue as you are transitioning to the main from the needle. I'd try to raise the needle once you have the 127.5 mains in there. Check float level too and make sure that's up to the gasket level. Also make sure the hoses to the airbox are in and not ripped.
Cool.
Srinath.
Sprayed the carbs and intake tract with WD-40 and rode it today. The misfiring and dying are worse along with some wicked backfiring as it dies. I am now 99 % certain it's the carbs loading up. Will post more as I work over what I know of carbs and/or have the dealer rebuild and sync them. Thanks to all and if anyone else has ideas lets hear them! Thanks again! 8)
8) Thanks to all who tried to give advice. Let me tell you if any of you have carb problems like described here give "Greased Lightning Carb and Fuel Injector" a try. It took running two tanks of treated gas to COMPLETELY clear up the problem. I should say the bike sat for a week inbetween tanks due to work and weather which gave the treated fuel in the carbs a chance to work. Again THANKS! 8)
there is also the option of dis-assembling the carbs and cleaning them out in carb cleaner. (removing all plastic and rubber parts first.) :dunno: