Clutches and Over-reving

[Dizzixx]

I have a 77 GS 750, wiseco 2mm overbore, dyna s ign, vance and hines 4 into 1, etc etc.

It only has 2k on it since it was bored out and cleaned up. While the guy was in there he had to replace 4 valves. I also had a new clutch put in.

First, what is the correct way to adjust the clutch. I cant seem to get it right. Either it wants to pull forward while I am stopped at a light with the clutch dis-engaged or it wants to slip when I give it gas above 6k, I just cant win. Also are there any heavy duty clutch options? There were not at the local bike shop I had to go with the standard barnett clutch and springs.

Secondly how badly does over revving affect this bike. Its not something that happens often but it does happen, I have a tendency to thrash it and sometime try to shift clumsily/too fast and it will slip and over rev.

Another thing while I am at it. It was running too lean so I went into the shop and he adjusted the air fuel a little, now it is good as far as starting goes but after a spirited jaunt on the freeway when I come to a stop at a light afterwards it just wants to die normally it idles around 1.5k but when its acting up like this it floats around 1k and often dips below to the point that the oil light comes on for a second. What could be causing this?

Thats a bunch of questions, hope you guys dont mind. Thanks in advance for any responses.

[BassCliff]

Hi Mr. Dizzixx,

I'll share what I've learned from this forum. (Plus it will bump your post back to the top where somebody smart might see it.)

Many members will replace the clutch springs with the heavy duty APE springs but then find that the pull is too hard. So by using half APE springs and half OEM springs a "normal" pull is restored and slippage is eliminated. As for adjusting, here's a clip from my manual...




As for "over revving", what do you mean? Are you going over redline when you miss a shift? If not, I wouldn't worry too much. I hope you're not slamming it into gear when it's revved to high. That could be bad on the transmission. With practice, your shifting/clutching technique will improve. Be sure to shift positively (not tentatively), good boots will help. You'll cut down on the "false neutral" syndrome.

You may be having some kind of fuel issue. Are you using an inline fuel filter? If your tank and carbs are clean there really is no need for a fuel filter. Fuel filters can be too restrictive causing fuel starvation. Use a lawn mower filter if you absolutely want to.

Are your carbs really clean and properly adjusted? The guys at the shop probably don't know these bikes as well as they should. It sounds like it's pretty much running OK so you might get lucky if you run a couple of good doses of Seafoam in a couple tanks of gas. If not, you should probably ensure the carbs are clean, adjust the float height, ensure there are no air intake leaks in the intake boots/O-rings, etc.

When was the last time the valve clearances were checked?


Thank you for your indulgence,

BassCliff

[Dizzixx]

Thanks for the manual scan. And info on the springs.

Yeah I mean over rev as in past red line. Normally its just 1 or 2k but today I was really hauling ass and I was trying to shift to fast and had not fully released the lever before getting back on the gas and it shot all the way to the end of the tach.

No I would never try to slam it into gear while reved up that would be pretty retarded. I dont have false neutral problems. Its actually all but impossible to get it into neutral while its running.

I really dont think it is a fuel issue as it is just after a long legged jaunt on the freeway. I mean it could have something to do with heat which then in turn would be causing fuel issues but I do not think it is the fuel filter. I have one of those see through plastic cone types its both clean and new.

Carbs should be both clean and adjusted but they could be a little out of wack. Which could explain it. I also wouldnt be suprised if its the boots from carb to head that are leaking air when hot or something. I forgot to mention that it has emgo pod fitlers, the carbs are tuned for them and they seem to seal fine at the carbs.

Last time valve clearance was checked was 2000 miles ago when I had it in the shop being rebuilt. Actually I think they were also checked when I took it back in after the 500 mile break in to be checked. I have wanted to check them. I started a log book for the bike when I had the work done, and I asked the guy at the shop what he recommended for service intervals and he said 5k on the valve clearance, the reason I have not checked it yet.

I both trust and respect the guy that does the work. I also know he knows what he is doing. His name is Jake Geiser (not sure if thats spelled right) of G&G motorcycles in Salt lake, he looks like he is 60, he still takes his built up GS 1100 ( think its an 1100) to the drag track every weekend he can. When I say built up, I mean pure drag bike, not street legal, with a turbo, etc. He has 1/4 mile speed records on his wall from the 80s. He always knows what I am talking about even when I use the wrong terminology and has been more than fair with me. I dont think thats the problem. Even if it was it would most likely have something to do with something I told him I couldnt afford or something of that nature.

[BassCliff]

Hi Mr. Dizzixx,

That's exactly the kind of shop you want to find if you have any shop working on your classic motorcycle. It sounds like you have a good thing going. Regardless, there is a list of maintenance items and adjustments which must be checked/repaired/replaced before further troubleshooting will be fruitful.

Click here for the "Top 10 List" and other suggestions.

With pod filters, the carbs probably require larger jets. But I'm sure your wrench knows this. Stalling when coming to a stop could be a float height adjustment issue. You just might try removing the fuel filter and running the bike on "PRI" (Prime) for a while and see if the symptoms go away.


Thank you for your indulgence,

BassCliff

[Dizzixx]

Yeah he put in bigger jets. He was borderline on going up another size if I remember right.

I understand that it could be this or that. But do these things account for the intermittence of the issue? That is it only seems to happen when it gets hot, and not like normal hot, like toping it out and holding it there hot.

I already know my bike passes most of the checklist. I will have to check on the remaining things.