I really have problems with belts jumping teeth.. I would think that the belt would have to be very very loose for it to happen, or the teeth were missing on either the belt or pulley.

( Should this say "rarely" )

@Max Headflow

 

Toothed belts don't slip! WTH. Some Gates belts may stretch a small amount when first placed in service but not much. How would it even be possible for a compensator to slip!! Something is wrong!
c

 

Either way.. I don't believe it happens.. I've worked in bike shops where I've seen chains jump teeth but in order for that to happen the teeth on the rear sprocket were literally almost gone.. One place I saw it, I worked at for a short time was called TLC motorcycle repair. Owned and ran by a Korean named Randy Kim... He was so cheap he could squeeze the buffalo off a nickel.. TLC was supposed to stand for "tender loving care". The guys that worked there knew it stood for "Tough Luck Charlie"

 

Charlie, a compensator is just a spring-loaded ramp device. Typically they 'slip' when starting the engine. The sound made is similar to the starter milling on the ring gear. It's nasty. But, yea, they can 'slip''. Although at this point I'm not thinking that's the problem at all.

I might also point out to those who seem skeptical of the drive belt jumping teeth, while I'd agree it's rare, AND..... it would likely be associated with some kind of damage to the teeth, I CAN happen! Yes, the belt would likely be very loose. AND.... that brings me back to the 'stretching' thing. I believe someone above made the statement that ..." toothed belts don't stretch!". Perhaps that should be amended to '...aren't supposed to stretch!'. Again, I'd probably agree that they shouldn't. BUT.... what if I'm dealing with some after-market 'junk' belt.....and what if it IS stretching??? Remember, 3 times now I've adjusted this belt, and each time it came back looser than when I started after just one spin around the block. This kinda makes me wonder.....???? Belt stretching? Axle shifting? Adjuster bolts not holding position? WTF???

Anyway, as stated, I've not 'tightened' this belt TO SPEC 3 times, including this last time where I used both a 'borrowed' belt tension gauge AND double checked with a NEW BTG. And.....the problem remains. SO........... as I too am of the opinion that at this point the 'jumping' belt just seems too unlikely...... I'm going with a slipping clutch. Again, I believe someone above made that suggestion early in this thread! Honestly, were it not for the belt becoming WAY too loose on the first go round, I might have gone with the clutch initially. However, and again this is kind of an 'experience' thing, I typically have experienced 'clutch slippage' in higher gears. As we all know, the 'back-torque' of the motorcycle is generated more in 5th or 6th gear than in 1st or 2nd. That's why one shifts to 6th gear to turn the engine over with the rear wheel when doing engine work....right? Right! So, that too is 'typically' where clutch slippage is noted. However, in this case, the slipping I'm feeling is not until I really twist the throttle in 1st gear. If just gently riding from a standing stop, shifting into 2nd, 3rd, and 4th....... I feel no slippage at all. I might also add that this bike has been operated by a relatively 'rookie' rider, AND, it's been on 2 extended trips. We just returned from a 2500 mile run 2 weeks ago where the bike was fully loaded. Last summer we did a 3500 mile ride, again, the bike was well-loaded. These two rides along with maybe a couple of 100+ mile runs are about all my friend has ridden this bike since purchasing it. And, I suspect he might have been doing a bit of engine-revving and clutch-slipping to break-away from a dead stop while on these trips, particularly with all the weight he had packed on this bike.

Anway, I'm making one more try today, doing yet another 'clutch adjustment' and giving it one more shot. If I experience the same symptom, tomorrow I will go buy a set of clutch discs, soak 'em for a few days, and then install them and see if that cures things. Beats buying yet another belt and doing the install on it, particularly if the belt on there now is NOT the problem!! I'll update as I go, and again, I appreciate the comments thus far! This IS an 'oddball' situation. And, coming right after the frame weld failure, it's more of a coincidental thing than an associated problem, or so I believe at this point. Last comment: When doing the belt install after the weld failure (described in the entry post), the fluid drained from the primary seemed a LOT darker to me than I expected. At the time I really didn't think much of it, but now in retrospect I'm not sure but what that might have been a tell-tale sign of this being a clutch problem. I guess my friend, being as 'conservative' a rider as he is, never experienced any slippage the way he rides it....other than perhaps what he was doing to it when he made his break-aways at stop lights or intersections. Had he said "I think my clutch is slipping...." I might have gone that way first. But, this was about replacing the belt and fixing the broken weld on the rear swing-arm/triangle/fork......or what ever you want to call the back end of a softail!

More later!! Tom D.

 

My .02
* Its a fakeydoo belt
* The clutch
* Something else is broken and being missed

 

If they ship while starting, why don't they slip in 6th gear?

 

Max, the purpose of the compensator is really two-fold: First, by design, the 3-stage spring ramp system is supposed to have some level of directional movement in it under certain operating conditions. The name 'compensator' comes from this fact. It was originally designed with the intent of 'compensating' for the unmatched power strokes of the Harley engine. This was to smooth out the operating aspect, as well as add some life expectancy to the running gear between the crankshaft and rear wheel. The OTHER thing it is supposed to do is be a life-saving device should the rear wheel or trans go into sudden lock-up. With the weight of the flywheel and power of the engine itself, a sudden and complete lock-up of the trans/wheel could potentially result in damage to the engine if there were not SOME form of safety device involved. Essentially the compensator 'de-couples' the engine crankshaft by ratcheting over the ramps if a lock-up occurs.

Here's the rub: First, HD has had some issues with compensator design over the years. I'm not sure exactly when, but because of these issues, HD pretty much abandoned their original 'smaller' compensator and went with their Screamin' Eagle compensator on all the big twin engines......and I believe this was somewhere post 2010. I say this because I just replaced the old style compensator on a friend's 2010 Ultra with a new SE compensator about 2 months ago. But, to understand this completely, you need to recognize that the two purposes stated above take some pretty tricky design if it's going to work properly. Hence the spring loads within the compensator....those that hold the 'cam' portion into the ramp portion, those springs need to be of a very specific tension. Too much and it won't release at all, too little and it will release pre-maturely.

Early Compensators were subject to spring fatigue. In most cases this fatigue was sufficient to cause some level of ratcheting during start-up. This was not necessarily common on ALL engines, but it was generally a problem on engines with some top-end work done, and particularly if you raised the compression ratio. Case in point might be my 2001 Fatboy, where back in '08 I'd gone with the Zipper's Muscle kit. This took the bike from an 88 to a 95, but also bumped the compression ratio from somewhere in the 'stock' range of maybe 8.5 to 9.0/1, to 9.5 to 1....or maybe a bit better depending on overall tolerances. Anyway, over the next decade the bevel springs in my compensator had begun to fatigue, and that bike was starting to exhibit that ratcheting issue on start-up, particularly when hot. Many people mistake this for being a bad starter drive, so they replace the starter and still have the problem. This is when they get a lesson in Compensators.

Anyway, bottom line is that even a pretty badly worn set of springs in the old style compensator will generally have enough 'hold' left in them to avoid ratcheting in 6th gear. But, I suppose it could happen, and maybe someone here has had it happen to them. It hasn't to me. In the end, HD pretty much resolved this by moving all the big twin engines to the Screamin' Eagle compensator, that has a much more robust set of springs in it, as well as 2 more of them. There are some companies that sell a engine crank gear to replace the compensator that is a solid, non-spring loaded device. Great for drag racing, but not really recommended for street use (unless you're really intent on beating your buddies from a stop light). These also run the risk of crank/engine damage in most any kind of trans/rear wheel lockup. But, that pretty much covers it. If I've errored somewhere here I'm sure I'll get corrected. But, the HD Compensator is really an ingenious device, and I'm not sure if it's a HD design originally or if someone else came up with it. Either way, if you have a severe 'clunking' when starting your bike, particularly a twin-cam from '99 to 2010, checking to see if you have the early compensator is a good idea. If so, replacing it may be all you need to fix the issue.

Hope this helps.

 

Max you got schooled! So why didn't this happen with the old belt?

 

Jake, it actually might have been happening all along. I just didn't know it cuz it's not my bike. As I stated above, this bike is owned by a friend. I actually helped him buy it. Long story short, I had planned to go to England and ride Great Brittian. At 72, it 'was' kind of a bucket list item of mine. When I told him, he said he'd go with me. I laughed..... he had no bike, no license, no riding experience. I told him (2 years ago) if he got his license, we'd go. He did.....but I backed out (last spring). Cost of plane trip and bike rental would exceed the cost of a nice trip here in the USA. He bought himself this '08 Softail Deluxe, and we took off last July for Naples, FL. After that trip we did a few more local rides last fall and this spring, but I bet he didn't put another 500 miles on his bike. Anyway, we just did this trip to Maine and Canada, and on the way home the weld broke off the back of his bike resulting in the wedging of the belt guard between the belt and tire and the rear swing arm. He made it home, miraculously, but tire torn to shreds, as was the original belt. So, me being the HD 'tech' guy, I did the R & I on his rear swing arm, he re-welded the bracket, and belt was replaced (he got it) along with a different rear wheel and tire. After reassembling everything, this was the first time I've ridden his bike since he got it. So his 'technique' may well have been sufficient to be wearing this clutch over the past 5 to 6 thousand miles. As I said above, he has 'test ridden' this bike since this repari work has been done and he claimed no experience of the problem. BUT, as I also said, he's NOT so aggressive with the throttle so as to have gotten into 1st gear in the upper RPM range on a fast acceleration. So, that's why he may not have experienced this. If I gave it back to him right now and said 'it's fixed', he'd probably be fine with it. BUT........ I KNOW there's something wrong.....so I'm not going to do that! But, that's why I didn't know about it before. Hope this makes sense. TSD

 

All I can say is wow - to post #17.