Connecting Rod bolts

[Appie]

Good day all

New owner of an ‘80 650C which my son and I are rebuilding. It started out with us taking off the carbs to get it going and now the top end is off and we’re contemplating doing the bottom end
Apologies if I’ve missed a previous thread. I’m wondering the connecting rod bearing cap bolts can be re-used or if they are stretch to torque?

I have to add a massive thank you to all the moderators/ members who keep this site alive! You guys are invaluable to novices like me and I’ve benefitted hugely from the advice and wisdom on this forum

[kerryb]

Welcome, you won't find much activity erre, but there's a lot of good info.
I found this on SOHCforum.

Screenshot_2024-03-19-10-25-23.png (179.27 KiB) Viewed 423 times

If you get into the bottom, check the starter clutch, I had to replace mine (cheap on ebay) there is a tutorial on here.

[Appie]

Yoh kerryb that was quick!

Ok so no new conrod bolts unless damaged. That will help the bank balance

And thanks for the heads up about the starter clutch. Looking at previous threads I think that means new springs/rollers/caps (thank you Mr Volker)?

I have a little lateral movement of the small ends of the conrods but minimal up/down movement. Can I make any judgement about bearings from this before I open the crankcase?

Thanks again for your advice

[Volker_P]

Welcome here!

I have to add a massive thank you to all the moderators/ members who keep this site alive! You guys are invaluable to novices like me and I’ve benefitted hugely from the advice and wisdom on this forum

Thanks for feedback! But unfortunately it looks like there is a problem for the future.

And thanks for the heads up about the starter clutch. Looking at previous threads I think that means new springs/rollers/caps (thank you Mr Volker)?

Usually this solves the problem. In very rare cases the starter clutch housing may be already smashed or the surface of the cam could have marks.

The tolerances for up/down movement in the connection rod bearings are typically much closer than for lateral movement so basically your finding sounds reasonable. You can find the specs and service limit on page 12-1 ("crankshaft") of the manual linked in my signature.

[kerryb]

One further comment on the starter clutch. Mine was damaged because the screws that hold it together came unscrewed! Scraping the screw heads against the next part while spining.