Top End Work

[yourpalcal]

I’m finally getting around to cleaning up the engine on my 72 R75/5. I purchased the bike last year and the prior owner did all the cosmetic work but nothing to the engine. I’ve got a few leaks from the right cylinder, drive boot and the clutch gasket. I consider myself a decent mechanic and rebuilt my Bing carbs but not experienced with airhead engines and plan to hire someone to do the bottom end. The leak down and compression tests came back fine. Both sides had around 147 compression.

My question is should I take the bike to a BMW certified mechanic which quotes me nearly $2000 for a bottom rebuild or use my local shop that is half that. The mechanic there has more experience with triumphs and modern bikes but is meticulous. He will clean the seat the valves, replace all gaskets and hone the cylinder and add new rings (if needed). I trust his work but is the BMW engine so complex that I should only trust a BMW certified mechanic?

Thanks for the input. I’m new to all this. I’ve only owned off-road two strokes and they are much easier to work on.

[Kurt in S.A.]

IMO I would go with someone more familiar with the Airhead engine. I used Ted Porter in California to do the top end on my /7.

Kurt in S.A.

[enigmaT120]

Why do you think the bottom end needs work? How many miles on the bike? I have 110,000 or so and never needed to mess with the bottom end.

[Rob Frankham]

Fix the leaks, ride the bike! If there's nothing to say it needs a rebuild, leave well alone... if it ain't bust don't fix it (or more to the point don't pay someone big bucks to mess with it). Odds are it will never need a bottom end rebuild.

In any case, if it ever does need a rebuild, this is well within the abilities of a half decent amateur wrench.

Rob

[ME 109]

In any case, if it ever does need a rebuild, this is well within the abilities of a half decent amateur wrench.

As long as the half decent amateur wrench has the special tools required, or can make them. As well as knowing how to retain the front main bearing.

[Rob Frankham]

In any case, if it ever does need a rebuild, this is well within the abilities of a half decent amateur wrench.

As long as the half decent amateur wrench has the special tools required, or can make them. As well as knowing how to retain the front main bearing.

If there was any doubt of that, he wouldn't be a half decent amateur wrench...

Rob