Seized Engine Disasembly Question

If an engine is seized and I am disassembling, is it important that I get the second cylinder to TDC? Or will I be able to line everything back up when reassembling?

The bike is a 84 Maxim 400. The service manual instructs to crank the engine by using the bolt on the AC generator to get it to TDC, but I can't get it to turn with mild force and don't want to damage anything.

 

I'm no XJ guru, but if engine requires a top end rebuild your not going to do any further damage. Cylinders will need to be rebored and need to come off anyway.

I'm feel certain that when you rebuild as long as you reset all timing marks it should be fine.

 

That's what I figured. I just wanted to make sure before I moved forward.

 

bludytiger:

The project you are embarking on, ... repairing that 400 ... could very quickly cost you MORE than what the Blue Book Price for a 400 in Fair to Good Condition would be.

NADA Blue Book
83-84 -- Yam 400 Max-K
Very Good: $675
Good: $375
Fair: $175
Poor: N/A

 

NADA Blue Book is the devil... There's NO way you can tell me my bike is worth only 700 bux lol

 

Once the cams are removed, the valves are safe from interference, so further disassembly can be done with the crank in any position.

Reassembly, though, requires everything to be at a specific position... usually 1/4 at TDC.

 

Repairing ANY of our bikes would likely cost more than Blue Book. Are you saying we shouldn't fix them at all? My 750 looks like it might need the starter clutch done, and we all know how much fun that is. (I've never done it.) According to you, I should scrap the bike.

 

I think his point was more that the OP might want to check on the price of a known-good used engine first, especially considering how expensive and hard to find pistons, rings, etc, are.

The odds are bad at finding a used 750 engine with a good enough starter clutch. And the parts for the starter clutch are not that expensive, so, if you're doing it yourself, I say it makes perfect sense to do it.

 

Starter Clutch: Apples
Seized Engine: Oranges

When your running Bike needs a Starter Clutch; you got a running Engine that needs a couple of Parts and whatever else you want to do Preventive-ly.

Everything you can conjure about why the Small Engine locked-up ain't good.
Oil starvation. Totaled.
Rusted. The Small Mill doesn't have all the Oversize Options a Middle-weight does.

If you need a whole Engine; chances are you score a used one for $300 or so; or buy a whole bike to get one.

That's where I was coming from.

$295.00 -

http://cgi.ebay.com/ebaymotors/1982-XS4 ... ccessories