1967/1969 Bonnie Rebuild Desert Sled Project - Any Advice

thanks for this comment. I decided to take it apart and try again as I had another issue.

 

In addition to my concern about the crank’s freedom of movement, I noticed that every once in awhile the left rod stuck slightly at the same place. It didn’t happen all the time but when it did it was at the same place. So when I loosed the case bolts quite a bit, then the crank ran freely and was able to rotate on it’s own when the rods were at the bottom of the stroke - very nice and smooth. However I still had that small hitch/glitch/check occasionally on the left rod right at the same place. It was when the big end of the rod was about 110 degrees from the top - so the big end is towards the bottom of the case. This was quite consistent, it didn’t always happen, but when it did it was in the same place. So I could not really have a clear conscience to not check this out. So I separated the cases and when I checked the left rod there was not problem with it’s rotation on the crank. So I noticed that the end of one of the left rod bolts seemed to have some abrasion, that is some of the black was off of the nut edge. I thought that maybe it was hitting the inside of the case somewhere. I also found a shiny spot on the inside of the case that seemed to align with where/when I thought the rod was sticking. My rod bolts are new from JRC, they were the same dimension as the old rod bolts. I spoke with a gentleman at JRC about the bolts and he sent them my way. So I got out my old bolts, and it looks like the edges on the top of the bolt(s) were ground down a bit and polished. I suppose someone may have done this before assembling. So at this point I may need to get my Dremel out and take a bit of the edge of these rod bolts off. While I just have them sticking at one point I should probably grind polish each of them because I wonder if when the engine heats up and expands there could potentially be more rubbing. Has anyone had experience with this sort of thing? Thanks!

 

OK, thanks for the advice. Since the prior bolts had some material removed, I've gone ahead and polished a bit off on the bolts and case. If the tolerances were so close, I'd hate to think that would lead to some future bad event.

 

Well, I never thought this might be an issue to contend with. Amazing what one needs to consider that isn't obvious to begin with.

 

So, finally got the cases back together again and all is good. Crank rides smoothly and no glitches with the rods.

 

Yes, I really want to get more than 10 seconds out of this motor. So fitting stuff a couple of times before I assemble it is ok. So I've put my transmission together this evening and seems like it is ok. I haven't buttoned it up yet though as I'm having some issues regarding how to index it and know it is correct. The workshop manual and Glenn's seem a bit sparse on this topic. My engine is also on a bench so I can't engage the wheel, etc. If you have any tips I'd appreciate knowing them!

 

Indexing my transmission and checking it. I am having some difficulty knowing if/when I’ve indexed may transmission properly. I’ve tried it in 1st gear and 4th, according to some methods I read about. However how do I know for sure that it is correct? A couple of times I knew it was not right as there would be one shift, then no more. Since the engine is out of the bike how do I go about checking to see if it is indexed properly? First time for me! Thanks for any help.

 

Thanks all for the advice. I’ll keep at it and feel much better since you’ve identified that this is often a difficult challenge. One thing more . . . once you think you’ve got it, do you test it by just making sure you feel it is going through all the gears? So if indexed at 1st, then you are able to move it up 3 clicks to 4th and then back down to 1st, then it is stopped? Thanks again.

 

Thank you all for the comments on indexing the gearbox. I now realize that this is sometimes not an easy chore - which makes me feel much better. I will keep at it!

 

I am trying to find a replacement for the felt washer/seal in my speedo gearbox. I haven’t had any luck with this. Do any of you know where I can order this part? Thank you.