Bike will not go any faster then 50mph

[talltec]

Hi there

This is a gs650GL 1982 i bought it used it a lot of work including the carbs to get it running it was bad shape. we got good idle and throttle responce and the carbs a synced but for some reason when taking the bike out the bike will not pass 50 mph it doesn't hickup or it just seems like i hit the top end of the bike. does anyone have any suggestion what might be causing this. the bike has factory pipes and air box

thanks

Manny

[GSstiny]

First things first. Be sure youre getting fire to all the cylinders, then go from there. One coil sends spark to 2/3 and the other to 1/4. Switch plugs around, see if they are the culprit. My bike had the same problem, turns out it had a dead plug that had caused it to drop a cylinder.

[Jethro]

I had this problem before. Check your clutch cable routing. On many GS bikes the clutch cable passes down between the #1 and 2 carbs, and there is a small wire that is there to hold the cable away from the carb body. I neglected to install that and the cable was hitting the throttle body adjuster.

[onchiman]

Will it pull past 50 in any gear at all? How about revs? Does it rev well?

[rgierer]

It has been my expereince, limited as it is, when the bike performs in this way 1 of three things is going on.

One occassion I had a coil malfunctioning causing 2 cylinder to not fire.

The second occassion it was a fuel problem casuing some of the cylinders not to fire.


The third occasion I had a poor charging system and was runnning on the end of the battery and nothing was really working properly.

These were all relatively simple fixes. Hope for the coils, i found it to be the chapest and most straight forward to resolve.

I think my question is when you start the bike are all 4 pipes getting hot?

[nabrams]

rgierer is on the money. It is almost certainly one of those three things.
The coil problem can be really hard to detect. A failing coil can fire just fine at low RPM (and a visual spark test will pass) and then not at all (or intermittenly) at high RPM. The bike will still run fairly smooth if the engine is turning fast enough. If it is a failing coil you'll know for sure when the coil finally dies totally.
Another thing that is hard to detect and leads to the same symptoms is a failing charging system. At higher RPM, with the lights on, and a faulty charging system (not producing 14.x volts at high RPM), the draw from the battery may be just enough to cause weak/intermittent spark.
I've experienced both of the above.

[talltec]

So were do i find the coils cheap

the dealers near us are looking to get 100 a peice and not sure we want to spend that if we not sure that whats wrong with it we charged the battery and its reading 14.4 and the plugs are new and the wires as far as we know are in the right place


thanks

Manny

[Tarbash 27]

check ignition timing, make sure brakes arent locking up, and clutch not slipping, make sure you get full throttle.

[talltec]

not sure how to check the timing on a bike so if you can explain that would be great and as for slipping clutch al not realy sure how to tell if it slipping the throttle seems to work fine when in nutreal but but it seem when i get to the 50mph i have it wide open to get to 50 in all gears


thanks
Manny

[Tarbash 27]

Very easy to tell if slipping clutch, you ll smell it burning up, it will rev up quick and bike wont move any faster. now that i remember, your bike has electronic ignition, its non adjustable. 1980 and up are preset whereas my 1979 is adjustable, sorry forgot. what rpm is the bike at 50mph in your highest gear?

[talltec]

Could it be slippage if I have to play with the clutch and throttle to get a decent start? If you don't do that, then it seems to hesitate severely, requiring me to give it full throttle.

As for the RPM question, the tachometer is inoperative at the moment, but when the bike is in neutral, you only have to go to about half throttle before the bike starts screaming.

The bike gets only half the RPMs (going by the sound) when it tops out at 50mph. It doesn't matter if it's 3rd or 4th gear and that is full throttle.

[talltec]

by the way if we sound novice we are we still learning about this bike we only had it about 2 months and have done a lot of work on it with out any help. till now so we are still learning about this bike since our last bike we had was seca II 600 we had no problems with it.

[Tarbash 27]

is there any play in the clutch lever before you feel some resistance. if the bike is running in gear with the clutch held in, and you just drop the clutch, does the bike jump on you than die out? it should if its enganging good, if it drags along than its slipping.

[talltec]

yes there is some play at the begining when you ingage the clutch as for if got the bike in neutral place the bike in 1st gear and let go of the clutch the bike hopes and dies

[Tarbash 27]

ok, not the clutch, do you have any modification to the bike on the intake or the exhaust? are you sure its running on all cylinders. do you know the mileage of the bike?