Seller screwed me over - New bike wont rev past 9000RPM | Page 2 | GTAMotorcycle.com

Seller screwed me over - New bike wont rev past 9000RPM

Great I got taken hard on this bike. Another problem presents its self the tach is all messed up it was idling around 1000 yesterday now the tach shows zero. When I shut off the bike it stops at 2k even tho bike is off, if I shut it on and off the tach goes back to zero
 
ThrottleThrow said:
Great I got taken hard on this bike. Another problem presents its self the tach is all messed up it was idling around 1000 yesterday now the tach shows zero. When I shut off the bike it stops at 2k even tho bike is off, if I shut it on and off the tach goes back to zero
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I'm going against the grain on this one ... you have a dead miss. One cylinder is not firing, could be a spark plug, coil or ignition module. Given your tach issues, I would guess ignition module or coil.

Take the bike in to somone who know's what they're looking at.
 
sircastic said:
I'm going against the grain on this one ... you have a dead miss. One cylinder is not firing, could be a spark plug, coil or ignition module. Given your tach issues, I would guess ignition module or coil.

Take the bike in to somone who know's what they're looking at.
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That's entirely possible as well. If he pulls the plugs he should be able to see if one or more cylinders are affected by lack of spark. That's a fairly easy operation to perform for the OP if he's short on cash. As you say though, taking the bike to someone like Pro6 would still be the path of least frustration.
 
I won't have spare cash for a while all my tuitions due in the next couple weeks I'm basically working 12 hour days just to cover that. I barley have money for gas let alone for repairs.How easy is it to tell if its running on one cylinder, what will the sparkplugs look like.
 
ThrottleThrow said:
I won't have spare cash for a while all my tuitions due in the next couple weeks I'm basically working 12 hour days just to cover that. I barley have money for gas let alone for repairs.How easy is it to tell if its running on one cylinder, what will the sparkplugs look like.
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A normal spark plug will look light tan in colour. White means it's too lean. Black means too much fuel or oil. If it's soaked wet it means there is no spark. Check each and see if any of them are noticeably different than the others. This will indicate which cylinder potentially has a problem. From there, you can try to figure out whether this is a fuel or spark issue. It's possible as well that your problem may only appear at higher rpms. Some coil packs will start to fail at higher rpm's first and will idle more or less normally. So simply checking for spark at turnover may not eliminate the coil pack as a cause. If all the spark plugs look the same you can start to think jetting as a whole may be the culprit. Or blocked fuel line. Hope this helps.
 
easiest way to check for a non-firing cyl is to run the bike and check the exhaust manifolds for heat

when the bike is warm, spray each individual pipe with a spray bottle.

the firing cyl's will steam off like dropping water on a hot frying pan.

the dead cyl will allow the pipe to get wet
 
reciprocity said:
easiest way to check for a non-firing cyl is to run the bike and check the exhaust manifolds for heat

when the bike is warm, spray each individual pipe with a spray bottle.

the firing cyl's will steam off like dropping water on a hot frying pan.

the dead cyl will allow the pipe to get wet
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awesome ill try this right now

FYI just took the bike out and tired to ride it with choke on, it didnt make it any better, if anything it just made it worse.

and at idle, if i pull the choke on, the bike dies immediatly, could we assume that this is because its running much to rich, rather then lean (kneedrager said if the problem gets better with choke on its to lean). the choke only seems to work if i give it a bit of throttle at the same time then it climbs to 3, 4 k
 
ThrottleThrow said:
awesome ill try this right now

FYI just took the bike out and tired to ride it with choke on, it didnt make it any better, if anything it just made it worse.

and at idle, if i pull the choke on, the bike dies immediatly, could we assume that this is because its running much to rich, rather then lean (kneedrager said if the problem gets better with choke on its to lean). the choke only seems to work if i give it a bit of throttle at the same time then it climbs to 3, 4 k
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Try Recipe's idea..that's a quick and easy way to check for dead cylinders. If it's dying right away with the choke it could be simply fouled plugs on one or two cylinders. If it turns out one or two header pipes are cool, check those cylinders for fouled plugs. Could also be the coil packs for those cylinders.

Keep in mind, bikes don't necessarily run well with the choke on full when they're warm so at some point you're going to have to look at the plugs.
 
hey i checked the headers, all the water seems to evaporate at the same time, the two middle headers mayb a half second-to a second longer. would that indicate a missfire or im probably okay?

my gauges are still messed up sometime the speedo doesnt display the right speed and sometimes the tach shows the wrong rpms

going to drop the needles tonight or tomorrow, see if that helps
 
ThrottleThrow said:
FYI just took the bike out and tired to ride it with choke on, it didnt make it any better, if anything it just made it worse.

and at idle, if i pull the choke on, the bike dies immediatly, could we assume that this is because its running much to rich, rather then lean (kneedrager said if the problem gets better with choke on its to lean). the choke only seems to work if i give it a bit of throttle at the same time then it climbs to 3, 4 k
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If it stumbles when you choke it that means it's running at a fine mixture... it'll rise when you open the throttle cause you're allowing it to breathe again.
This problem is starting to sound electrical... if your gauges aren't working properly either then you may have some electrical issues.
This oddly enough could be a battery problem, I know it sounds weird but it's possible. my battery was dead at the beginning of the season and I had trouble revving it as well. You're running it at a higher RPM than the battery can keep up with. Check the battery.
 
I think once you have eliminated an electrical issue you should take anoyther look at the carbs.
For example, what is the rev limit on your bike?

The reason for this is because your bike seems to be performing like one with flatslide carbs where just cranking the throttle open at too low an RPM could flood the engine if you have a large enough main jet.

The lurching motion seems to indicate that the top end is far too rich, borne out by the fact that gradual throttle application allws you to exceed 9000 rpm.

I think your issue if related to carbs could be threefold
1. too large Main jet
2. Slides rising too fast
3. Blocked air filter causing overrich mixture

Ask the seller if he had installed a jet kit and if so whether he has drilled the slides.
Dyno kits sometimes recommend drilling the slides because this allows the diaphragm to be evacuated more quickly when exposed to engine vacuum.

Thus, if the hole in the slide is too large, the rate at which the slide will rise, when exposed to engine vacuum will be proportionally greater. This will allow a higher vo;lume of fuel to enter the mixture. If the rise from the slides is too rapid the amount of fuel in the mixture for that RPM will be too great causing an overrisc condition, and in some cases causing this lurching motion. If it is rich enough the engine will cut out until you nclose throttle and reduce cavuum in the carb throat. Thus if at 6000 you whack open the throttle the slides could rise to fully open dumping fuel into the engine required for a much higher level of rpm. If you gradually apply throttle the slides will respond quickly but possibly not rise fast enough to cause the overrich condition. To correct this issue, you will have to unscrew the carb caps remove the springs, diaphragm and slides and then check to see the air holes in the slides and plug the one that was drilled (if there are two). The main issue here is ensuring you do this in a manner that will not allow the "filler" to be sucked into the engine. Perhaps the more experiences mechanics can comment on that.

You should trouble shoot as follows:
1. Check to ensure no blockage of air filter or airbox exists
2. Determine form seller if there is a jet kit and if so what size jets and needle poisitons and most importantly if he drilled out the slides. As well determine if the diaphragm springs were swapped for lighter ones (also employed to allow slides to rise faster)
3. If the slides were drilled then
-remove the tank,
-carb caps,
-diaphragm, and springs,
-and plug one of the air holes (possibly the smaller one if you still want to keep the quick response)
3a. At some point you will need to determine if the main jet was swapped and to what size. If it is outrageously large (ie stock was 130 and now contains 155) you will have to reduce this to something closer to stock. If there is a jet kit in, then bring it to the jet kit's recommendations if drastically over.

Unless you are running an aftermarket exhaust and some kind of aftermarket intake mod that drastically increases airflow, I would stronbgly recommend you return the carb settings to as close to stock as possible.

Carb tuning is a royal pain in the *** and you will be better off leaving it very close to stock.
 
If the power loss is abrupt and intermittent, then I would first fit new plugs and charge/change the battery. Also look closely at the ignition wires to the plugs and make sure they are tight on the plugs and not cracked.

/rs
 
Might sound odd, but I had the same issue with an older GSXR. In talking to the Dynojet guys I found out that the adapter ring in the K&N caused airflow problems, and they said either install it backwards (if you even have an adapter between the filter and the throttle bodies), not sure or just go back to the stock filters. Dynojet has a toll free troubleshooting line, give them a call! Believe it or not, I had a very similar symptom to yours, I reversed the air filter adapter an my bike ran fine. Good luck, looks like you found out why the previous owner sold the bike.

BTW, if you do decide to return the slides to stock, 5 minute epoxy is great for plugging the extra holes that might have been drilled. Often the main jet size is not changed very much, but often the needles are a narrower taper so that midrange can be richened without going overboard at the top end. Ah, the good old days of carbs........
 
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