Original Engine Rebuild

Ok, fall season is here and its time to restart my original engine rebuild. But before reconstruction I have always found consultation is the best method to avoid disasters. So, for those of you much more experienced than I, I am asking for the top 5 or 10 pitfalls to look for as I progress. Better yet, is there a bottom end rebuild thread available that I can consult??

All parts - crank, cam, covers, shells are either rebuilt with new bearings etc or vapour blasted. Really looking forward to getting started.

Thanks as always -

Great intro to the rebuild. Looking forward to your conclusion.
I will watch with interest.

FoundPeanuts "Closing the Crankcase Check List and Torque sequence". Looks very useful.

Also think Hans Pahl's "The Yamaha Engine" might be a good addition to my library.

I don't consider myself experienced .. but as it seems you are doing a high quality job by the looks of it
In general terms there a certain parts that are more prone for wear.
I would consider gearbox bearings and inspect the gears ..the first and second are most prone.
Not that I have heard about it on XS 650 but I have heard of one machine parked because a gear broke third I believe
I would think about Oil pump.
And cleaning the oil passageways I believe this is mentioned in Pohls book
Con rod Play and rockers play. ??
CAM shaft bearing is important in my view I had to split an engine because they gave up
left side ..
CAM Chain and adjuster and parts for that I believe almost everyone service on every type engine

If the cost gets to high with what is suggested please ask here .
I would not close an engine without cam-chain parts + tensioner up top date or without new Cam shaft bearings.
But this is not an exact science Saving now makes the next time come closer which can be acceptable.

Say fex that the pistons and cylinders will come out in a couple of years 3 - 4 -5 then that affects what needs to be done today.
If not it can be another situation

Take your time and use a torque wrench where it is important.

Some kind of engine stand is good to have. please google there are many versions.

There are service manuals on line that can help.

All good advice and much appreciated. Cam and crank bearings are all new. Good advice on chain and tensioner. Will do.

Thanks again.

Hoos racing has the best cam chain guide.

Very good pricing too.

http://www.hoosracing.com/new650750engineparts.html

OK, after a whole lot of fam obligations - Xmas, illness etc. Im back at my engine rebuild. Can anyone tell me how to check tolerances/functionalityn of a timing chain while outside the engine?

Shipper said:

OK, after a whole lot of fam obligations - Xmas, illness etc. Im back at my engine rebuild. Can anyone tell me how to check tolerances/functionalityn of a timing chain while outside the engine?

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I’ll give you the same advice was given to me. “Replace the timing chain.”

650 Central has a high performance peanut chain for reasonable $. I just installed my 2nd one.

Ya, for the price of it thats likely the best advice. Thanks Jim.