GS750 BREAKS UP at 5000 RPM's

[ToddB3]

Ndebt, I guess you got the shocks back, how did they turn out?

[Anonymous]

They are definitely lower than stock, only problem is now they bottom out on bumps they wouldn't have even came close to before having them cut by www.sotmc.com
I asked sons of thunder metric cycles for advice and he basically said they could put spacers back in the shocks, but that would raise it again. He pretty much so junked the shocks as far as I am concerned. Not happy and would not recommend at all. Hoping he comes up with a solution. He took out coil, but not the rod length, so it has completely softened the shock. Like I said, hoping he has a solution that doesn't involve me spending more money - I have 77 vested and the shocks are not really useable. I could have bought new lowered shocks from cyclerecycle for 89.

[Anonymous]

Oh yeah. New filter is not the solution. Bike now breaks up at about 5500-6000 rpms. Just like it is hitting a rev limiter. Has to be electrical or carb related. Will take more suggestions. Just doesn't seem like the carbs jetting could be that off = runs perfect up to the point of 5000-5500 rpms, then hits a wall....

[ToddB3]

Sorry to hear about the shocks, I was wondering how he could cut the springs and keep the dampening. I guess the search for lower shocks is still on.

[ToddB3]

Ndebt

I went to Cyclerecycle.com and it was a bicycle site, what is the correct web address?

[Anonymous]

http://www.usedmotorcycleparts.com/

[Anonymous]

https://www.crc2onlinecatalog.com

That is the correct address for cycle-recycleII. They have the 11" shock for 89. They seem to have a lot of good parts for the GS.

[Anonymous]

I changed the spark plugs and air filter. Ran the bike and it will break up at 6000 rpms. The #1 cylinder looks to be running slightly lean when compared to the others.
By the way, totally happy with cycle recycle II service.
Sons of Thunder Metric's solution to ruining my shocks was to spend more money shipping it back and forth so he could try to figure it out once more. I won't spend another dime with him. I don't want to be a part of his learning curve. He definitely messed up lowering my shocks. Oh well you live and learn.
Anyone have some advice where to start with the troubleshooting?

[KEITH KRAUSE]

The way you're describing it, it's a fuel flow problem.
If the bike rev's well in neutral (no load) but rev's to only 5,000 or so under load, it's lack of fuel.
It could be one or a combination of things.
Clean the gas cap vent. Be sure the petcock is operating right. Make sure you have a 5/16" fuel line and good vacuum line. Get rid of any fuel filters. Clean the carbs completely and check float height. A good carb synch always helps.

[Anonymous]

Hi, I have "cotton wood trees" by me. Perhaps you "inhaled" some of the cotton wood on the filter. Illinois. Dave

[RacingJake]

You never said what size your main jets are, maybe you got one of those famous K&N kits thinking that their jets are bigger than oem one's, but they are not.

If your done playing around with the carbs try the electrical side of the house.

Most problems are 90% electrical and 10% fuel related.

Here's a tip, Go ahead and hookup a timing light one at a time on each lead and rev the motor up while looking at the end of the gun. The light should not be erratic. Do it on each cylinder and see if they are all the same. If you find a problem just backtrack.

[Anonymous]

The bike revs up to 10,000 easily and falls back down just as it should when you release the throttle. I was told a bike with carbs that are out of synch would take a while to fall back down on the revs.
Another gs'er told me to check the points and condensors - does a 1981 still use points or is it electronic ignition?
I am still baffled. I do have an inline filter that I am going to attempt to remove.
If anyone has any more suggestions, let me know.

Thanks

[KEITH KRAUSE]

Another gs'er told me to check the points and condensors - does a 1981 still use points or is it electronic ignition?
I am still baffled. I do have an inline filter that I am going to attempt to remove.
If anyone has any more suggestions, let me know.

You don't have points/condensor. Besides a new air filter and plugs, what have you done? I think this is a fuel flow problem. See my previous suggestions.