Could it be the oil?

In an earlier post I mentioned that my engine seemed a bit rough between 2700rpm and 3500rpm in any gear. I don't think it's the engine itself since I can rev it to that range in neutral and it doesn't seem rough.

I played around some more and it seems like when I'm maintaning speed or accelerating, the ride is a bit rough in that rpm range. If I'm coasting in gear in that range, I don't notice it or if I pull in the clutch and try to keep the rpms in that range I don't notice it.

I noticed it after I changed the oil. I've attached a picture of the jug of oil I used. I looked and didn't see anything about friction reducers etc. Could the oil be causing grief with my clutch?

Thanks for your input.

mikeg

 

yeah dont mess with conventional oil. It doesnt have enough additives like zinc that are bikes need try this:

http://www.valvoline.com/pages/products ... product=76

you can find it at any autozone, oreillys, farm and fleet, advance auto,on another note its like 4$ a quart so its not overly expensive

 

I would not think the oil could cause a vibration. You could try some Rotella 15/40 and see if it makes a difference.

 

I had heard that certain oils can cause the clutch to slip. I don't know if that would be at certain rpms, all the time or what. So I figured I'd ask.

Make no mistake, I am NOT a mechanic!!! Nor do I play one on TV! I was proud of myself for changing my own oil. I'm 44 and I've never bothered to do it for myself before. So I'm just guessing and hoping that somebody in the group might have some insight.

The oil had been changed 2k before by a dealer. As I said in an earlier post, I did put on a spin on oil filter kit when I did the oil change though I can't see where that would have any issue.

thanks,
mikeg

 

Very unlikely the oil is causing this. Only reason I can think of is if the dealer had a heavier weight oil in it and there isn't enough clutch free play. You might try relaxing the adjuster a bit.

That oil is a bit on the light side, but probably ok this early in the season. Come June I'd go to a 15w40 or 20w50.

Since it's in the same RPM range regardless of gear I don't think it's in the drive line.

I wonder if perhaps one of you carburetor diaphragms has developed a leak. Mixture off a bit and one of the cylinders isn't pulling it's share making things rough. Not noticeable when not under load.

Also might make sure the carburetors are synced.

 

My bet would be a mixture problem - too rich, or, more likely, too lean around that point. Might be interesting to try a plug chop at 3K under load.

 

I agree 100% The Rotella T diesel oil is great for these bikes with its high zinc content.

 

so it's kinda under a load? that sounds like when a coil starts to break up. it would hesitate/stumble maintaining speed or accelerating. just a thought, i see it all the time on cars.

 

Rotella T for sure! I love it, and I haven't even had it running on the road yet. But preliminary testing in the shed - awesome. It seemed to quiet things down a bit, and the clutch digs really good!

 

MiCarl,

I checked my clutch cable and it was tight but loosening it did not fix the problem. It did seem to make it easier to find neurtral though. Does that make sense?

Could the Seafoam I put in the tank last fall have loosened up some gunk in the carbs and caused the trouble? When I took it out tonite after adjusting the clutch cable, I got on it a bit and it seems throatier even when it's not rough. Not sure what that might indicate. I didn't see anything on the pipes from the cylinders but I didn't check under the bike, not enough time.

One other thing I checked was to make sure all of the pipes were hot and I could feel the heat through the leather gloves I had on.

mikeg