| Author | Message | ||
     Hughlysses |
Just saw this thread on advrider and thought I'd cross-post it here: http://www.advrider.com/forums/showthread.php?t=53 8576 It's on how to lap your valve shims to the proper thickness. This assumes of course that wear in the valve train tends to result in a "tight" measurement so that you need to change to thinner shims when you do your adjustment. Lapping the shims may be time-consuming but no worse than stopping in the middle of the job to make a trip to the dealer to buy the required parts, or worse yet having to wait while he orders them. Anyone here ever tried it with their 1125 or another bike? | ||
| 1324 |
I've never personally done this, but I know guys who have....though not on an 1125 shim. Personally, I'd take one and have it sectioned to make sure the shims aren't case hardened. If they're case hardened, the answer is a resounding 'NO'. Of course, if they are through hardened and you go through with this, just make sure the surface finish is comparable to what you started out with. Then again, I always buy them and then commence trading with my other riding buddies when needed. | ||
| Avc8130 |
I just wish someone would measure the diameter of the shims when they have them out. Then I could go buy a shim kit from Hot Cams and not have to worry about whether the "local" dealer has the correct size in stock. ac | ||
| Hughlysses |
I wonder if Al Lighton could be persuaded to come up with a shim kit. An aftermarket Volvo parts company (IPD) does this for older Volvos. You "buy" the shim kit from them which consists of an assortment of several of each of the available shim thicknesses. You do your valve job, use what you need, and send the remainder back. Then they refund you for the unused shims less a small fee. Seems like a pretty good solution. Here's a link to the IPD kit: http://www.ipdusa.com/version.asp?strPageHistory=search&numSearchStartRecord=1&P_ID=4177&CAT_ID=0&V_ID=10500 (Message edited by Hughlysses on January 04, 2010) | ||
| Ccryder |
I tried it on a 60's vintage Ducati single. Those shims were just case hardened. It did not work. On the 1125 IMHO, I would not go that route since 1) The flatness has to be maintained. 2) It will be VERY time consuming. 3) If they are case hardened you run the risk of removing the layer of hard material. FWIW, they are they same diameter as the V-Rod shims. | ||
| 1_mike |
First, most case hardened steel is deeper than just a few thousands. Normally it's .008" to .010", many times it can be as much as .030" thick, per surface. If one only needs a coupla thousands, I'd say no problem. But if one needs .005" like I do, case hardened shouldn't be sanded/stoned. And the same for the parallelism. As Ccryder says, they do need to be parallel, espicially on the 1125 design, since they do spin with the valve and rocker motion. .0005" may not effect things too badly, but any more and for someone looking for a good wear pattern, might be better to wait. My 1125's been sitting waiting for a Harley/Buell dealer to open since 12 23 09 to start buying shims... Mike | ||
| Avc8130 |
I realize they are the same diameter as VRod...but I don't know what the diameter of a VRod shim is. ac | ||
| Xnoahx |
I think it was 10mm diameter | ||
| Avc8130 |
Is that 10mm accurate? Could it be 9.48mm? I BELIEVE KTMs use 10mm shims. ac | ||
| Zac4mac |
They aren't just the same size as V-Rod shims, they're the same part (number). | ||
| Avc8130 |
Awesome! The same PART NUMBER! That completely clears up the diameter of the shims. I think it is 100% WELL established that the 1125 and the VRod use the SAME shims. The question now is if an AFTERMARKET shim is available as a kit. To determine this we need the diameter of the shim. ac | ||
| 1324 |
I'm sure these shims are cheap. Buy one from the dealer and measure. Done. | ||
| Avc8130 |
But people are handling them all the time here. Someone should be able to measure one. If you are able to measure the thickness so you can determine the NEW shim you need you should be able to measure the diameter. Going to the dealer is a PIA. ac (Message edited by avc8130 on January 05, 2010) | ||
| Avc8130 |
Really the coolest concept would be if a site sponsor could put together a "kit". They could ship it to the customer with a deposit. Customer has 1 week to use the shims they need and send the kit back. Once the kit is returned the sponsor would refund the deposit minus whatever shims were used. OR just charge a flat fee for the service. Owning 2 1125s I still just wish Hot Cams would make a shim kit. Internet research shows 1125 as having the same shims as all other Rotax (Aprilia, Can Am) and even some KTM. ac | ||
| Family_buells |
It looks like the consensus is to not try to lap thicker shims down to the dimension that you need. I agree that this is a bad idea. The valve train one of the highest stress parts in an engine and reworking the shims wrong is going to be very bad. The risk of getting it wrong here in order to save a little time or money just doesn't make any sense in a high performance engine. Don't be cheap. Get the right part. Added: I checked the link. He's doing it wrong anyway. there's no way on God's green earth you're going to get it even that way. That's not lapping by the way. Its sanding. (Message edited by family_buells on January 05, 2010) (Message edited by family_buells on January 05, 2010) | ||
| Avc8130 |
The 1125 is shim UNDER bucket correct? The shim is captured between the valve retainer and the bucket, right? ac | ||
| Fast1075 |
There is no bucket...the cam operates the follower...the follower pivots on one end..the other end of the follower sits on top of the shim....the shim lives in a recess in the top of the retainer. Much simpler to change the shims than on a shim under bucket direct actuation design...the cams do not need to be removed...it would be extremely easy of you could get the valve covers off without rotating the motor. | ||
| Avc8130 |
Ok, so shim diameter is critical. Good news: I contacted Hot Cams. They will have a 9.98mm shim kit available around March. Now we just need a board sponsor to carry it. ac | ||
| 1_mike |
Ok...I've got four out of my CR waiting to be replaced. I'll measure them tonight. BUT...the number will be posted as four decimal points and in inches. Mike | ||
| Avc8130 |
Google knows how to convert to metric. ac | ||
| Firstbuell |
man, this is exactly what we had to do back in the late 60s when the desmo Ducati singles were about - collect/trade/wait for those damn shims...... price wasn't so good, but availability was the issue - still is, apparently.....  | ||
| Ccryder |
Yep, been there done that! | ||
| 1_mike |
Per my Brown and Sharp digital.... One intake I measured is oval...! .39325 to .39350 Mike | ||
| Avc8130 |
9.98mm perfect. Hot Cams is on it! ac | ||
| Smoke |
when i went to buy an assortment of shims from the local HD-B last august they had -0- in stock at 2.60 ea. i got lucky and was just within max spec. just did the race bike and within min-max spread closer to min so lucky again. we'll see next time! i want that aftermarket kit also! tim |
