I'm considering tackling rebuilding the two dead engines in my yard into one good un. Basically what I want to know is what parts should I assemble, tools etc.

At the moment one engine has no 2nd or 3rd gear and the other had the big ends go. So the idea is to strip them both down, check them for wear, clearances etc and then re-build them into one good engine.

Is this within the realms of the home mechanic (me) and do I need any special tools? I can get a complete gasket set, but will I need anything else? Valve guides, bearings etc?

Any advice gratefully received!

Cheers

Mike

I guess that It depends on which engine. Bike engines are nothing special and if you'd be happy to rebuild a car engine I wouldn'y worry about a bike engine. Get hold of the haynes manual and look at the number of spanners by each job. If it says "specialist tools" or "best left to the manufacturer" you know what you're in for.

There's nothing in there that you would need any particulatr special tools for, except maybe a flywheel puller. You may need to make some tools, such as a valve guide extractor etc. but you won't know until you get in there.

There are some bits that you may need to farm out (crank regrinding etc.) but it's still no different to any other engine.

Just be careful when splitting the cases as they are particularly fragile!

Depending how well you know both engines, it might just require a gearbox rebuild on the engine with the good bottom end. Personally, I would find stripping down a full engine and checking everything for wear, just for the sake of it, a bit daunting. Although the Haynes manual is good, there are still some areas it doesn't cover, which only come with practice.
I'm firmly of the opinion that 'If it aint broke, it doesn't need fixing'.

Phil

Hmmmm.... modern bike engines are more trouble than they're worth to rebuild if you ask me. Obviously there aren't realy any different bits inside them to a car engine but because they're relatively tiny, have lots of power for the displacement and are designed to rev waaay more than a car engine all the tolerances etc are that much tighter. Oh and you'll probably find all the bits you might need to replace are eye wateringly expensive as well .

You can get away with murder when rebuilding a car engine in comparison and it'll be fine - a bike engine probably wont (or a least wont be for long!) I'd have a go by all means but know when to cut your losses

No problem with that as has been said above, if you are happy stripping engines down car or bike.
I did just the same as you are planning last week.
i had 1 R1 engine that went bang on me at oulton park a couple of weeks ago.
i had another engine that i knew was o.k. but has a knackered 2nd gear.

I stripped down the blown motor took the necessary gears out (complete output shaft) and transplanted them to my other engine. getting to the gearbox on the R1 requires most of the bottom end taking apart except for the crank and con rods.
i took the opportunity to remove the cams and check the tolerances and then refitted them.
total time from removing the blown engine, rebuilding and reinstallng was 25 hours and this was the first bike engine i have rebuilt.

it cost me a grand total of £39.00

castrol R4 @ £25.00
oil filter @ £5.00
sump gasket £6.00
instant gasket @ £3.00


it fired up first time and runs great
i took it out yesterday at elvington sprint 4th place out of 8.