Shakedown ride - three issues

[TopCatGr58]

Patrick,

If you'll go the tech tips FROM THE MAIN FORUM PAGE, don't use the Yellow column links on the left, you'll find some newer tips, like the 1st and 2nd gear Dremmel fix, diagrams, pretty pictures and all! A decent read if I do say so myself!
T.C.

[prometheus578]

"How's THAT grab ya?"

In first gear, coming off the line, the bike jumps and rattles soon after the clutch grabs. It almost feels like the front end is jumping up and down. It smooths out after I'm moving and hit about 2,000-2500 rpm. I suspect it is the God-Knows-how-old clutch plates, but it doesn't really feel like a clutch slipping.

If your clutch has a problem in first gear, it will have a problem in every gear. The problem that Promepheus has described, would cause your clutch lever to feel hard and cause the clutches to slip. The problem you are having is the first stages of first gear being blown.

Not to disagree, but I'm known for being disagreeable.
Commando, if I may... The opposite is true. Might be just a different interpretation of terms. The common problem of this bike is worn gears, and the bike slipping out of gear. Succubus makes no mention of mechanically slipping out of gear. The clutch lever pull would feel the same, as it's only the pressure plate that moves when one pulls the clutch lever. If a lever feels hard, there's a cable or linkage problem. Weak pull... chances are the springs are shot. Clutches slip due to weak springs, or worn and glazed plates.
While it's true that a problem that affects being in one gear affects them all... This depends on load. A bike with a slipping clutch is usually not felt till in the higher gears. In first and second, due to the gearing, the slippage is almost unnoticeable, but in higher gears, when you crank the throttle, the gear ratio puts a greater strain on the clutch, hence the slippage.
Or definitions may be different. Slippage is when you can rev the engine, but the bike doesn't respond appropriately, that is, speeds up. What succubus is describing is a clutch "grabbing", intermittantly catching and releasing, till friction builds and everything turns as one unit.
In the example I stated above, due to the grooves not allowing the plates to seperate, the plates were dry. Oil lubricates the plates, allowing them to slip a little and then transition to full grab. Without the oil between the plates, they would just spin (friction material against steel plate) till friction heated them up and they made good contact. Of course, the bike would be jumping and lurching in the process.
He mentions that the problem goes away after it reaches higher RPM. This is because it's easy for a clutch to make a moving bike go faster, than it is for a clutch to get a bike moving from a standstill.
As I stated... I may be wrong... this might not be the problem anyway. But... when examining clutch plates, deep grooves are something else to inspect for. If you can feel them with your finger... you should smooth them out.

[HobbyMan]

I was having the same problem (#2) on my 80G right after I rebuilt and synched the carbs the night before. As it turns out, the yamaha manual says to use a different tach to get the rpm at 1000. Because I don't have a tach(that I know of), I just used the OEM one. I ended up synching my carbs at a rpm that was too high. When I ran it the next day, it stuck just as you said. When I got home after the test run, I synched the carbs again, this time at a lower rpm(my tach was showing about 900RPM or there abouts) the problem dissapeared. I thought it was originaly a cable or sticking carb butterfly but it was a sync problem.

[Incubus]

Hey T.C., I just read that tech post. I had Kama Sutra on Showtime on the 57-inch HD monitor right over the top of my laptop and I didn't see a single jiggle. I don't even want to do it, yet I read to the end. I had to see how it would come out.

If you don't already get paid for stuff like that, you should think about it.

Patrick

[Incubus]

Full disclosure: the bike does not slip out of first. After the initial shuddering - during which is is still accelerating - it smooths out and grabs well. I've had blow trannies in several bikes, including a bad first gear in the DT1 listed in my signature. That was a hard knocking rattle even before it began jumping out of gear. This doesn't sound like that. It could still be the tranny. I read T.C.'s detailed explanation for the fix. I could do it, I just don't want to.

I dismantled the clutch and cleaned it right after I did the top end. I had to - it was pretty much fused. I soaked the friction and steel rings in Rislone until they separated. I cleaned up the corrosion on the metal plates. The friction plates, after soaking in oil, were within spec, but I knew when I put them in they might not work out. They looked OK enough to try. One of my dirt bikes had the ridges in the clutch basket that you talk about, Pro. I checked this basket and the clutch boss and I didn't see anything.

I will be resynching the carbs tomorrow. I used a dwell tach when I synched the first time to check the rpm, I never have much believed in the accuracy of the onboard gauges. They're kinda like idiot lights. I've got another dwell/tach. I'll try it next.

Could timing also be the cause of the high idle? I wondered about that as I was pulling the pickup plate and governor to clean them up. They were in need of some cleaning and grease, but nothing that would cause these issues.

Patrick

[TopCatGr58]

Thanks Patrick,

The reprorts of folks being able to get their machines back up and running is payment enough!!

This might not be anything, but there are 3 ball bearings in the throwout mechanism in the clutch cover assembly, but if somehow the actuator got turned or rotated during assembly, one of those bearings could come loose, fall out, so that you would have uneven pressure during clutch activation?

Sounds like you're prettty good with wrenches. You said you removed the corrosion of the steels with chemicals, but did you go over them with some fine emory cloth?

Regrettably going back in with the old frictions, even though they may have been in spec may not have been a good choice? While you're in the readind mode, check out the tech tips in the MODS, about the Extra Steel Clutch plate technique. Also, you didin't say so, but you may have also used your old springs!

I removed the "new" ones that I had put in mine in 2000 when I did my Tech Tip this year, and several were already compressed below spec! That was only after 5 years, not 25!! The frictions are available from PNM for $5.00 ea, the springs about $10.00. The Steel from BikeBandit, you can get frictions and springs from BB as well. But with the PNM order, shipping will be FREE. BB charges about $7.00 S&H.

Hope it's just a carb synch issue!?
T.C.

[Goin Commando]

Not to disagree, but I'm known for being disagreeable.

I stand corrected. All of the slipping gears that I have encountered started off ok when being nice with the throttle then started slipping/poping out under more power. The way that Patrick has described is the opposite, must be something else.

I did not read about cleaning the the clutch/friction plates with the caustic chemicals, this could have ruined the cork fibers that make up the friction plates. being rusted together probably didnt help either.

[Incubus]

I took the XS for another ride and making some adjustments, as suggested in this thread. I had to squeeze in one last ride before the blue norther blows through tomorrow. It's going to get very cold and I won't likely be able to ride again until Saturday.

Anyway, I digress. If this repeats anythng I wrote earlier in this thread, sorry, but I'm too tired to read the whole thing over again now.

I actually found a shifter spring in stock at a local shop. This guy is cool. He's been in business since they sold XSes and he sold them back in the day. He's serviced them ever since. Over the years he has discovered the problems with all the models he sold and he tries to keep at least one part in stock to solve all the known problems. Interesting inventory. He's also a wealth on information on the bikes. I almost got greedy and bought out all of his on-hand XS11 stock

I installed the spring. First and second gear are right where they're supposed to be. Thanks T.C. And they're also solid. No slipping or thumping or popping out of gear. Good grab on accelation.

The clutch is working better as I put even a very few miles on the bike. It's still lurching somewhat coming off the line, but it's better. I don't think there's a problem with the transmission. To my experience, they don't often heal on their own. I'm going to give it a bit more time and see what happens.

The racing idle was more of a challenged until I decided to actually give it some thought (that can hurt). My petcocks are leaky as hell. They overfilled the carbs and backed up into the air filter. Great.

I hate my petcocks, I really do. I've mentioned in a couple of other threads already, but it bears repeating. They're sneaky. I hate sneaky.

My new front tire arrived yesterday. It's a 110/90-19 Dunlop F24 G. I haven't seen it mentioned in any of the tires threads, but it's a bias ply, it's brand new and it cost $21. No body else was paying attention to it. It looks like it will work. The XS is hours from roadworthy.

It's going to be tough sitting out this cold weather.....

Patrick

[HobbyMan]

Don't worry about the cold weather. It was 80 this morning and now it is 35 If it can get cold that fast, it can also warm quickly too. Its the rain that is troublesome. Maby tomorrow school will be canceled. Did you get the idle fugured out?

[Incubus]

I did, HobbyMan. Once I removed the gas-filled air filter I was able to get the bike to idle like it was supposed to. With gasoline vapors replacing air on the intake, it was running a mite rich....


Patrick