opinions about bottom end!

1982 XJ750 Maxim about 50K miles.

History unknown, I bought it for a $100 not running, took it home cleaned the carbs, charged the battery and fired it up. no knocks or any of the obvious indicators that I need to dig into the bottom end. HOWEVER, I have not rode the bike or shifted through gears.

Currently have the engine out and head removed. The heads been hot tanked and blasted and I'm about to do a valve job and install all new valve seals.
Compression tests were normal.
Was also planning on removing cylinders and cleaning them up. I have heard/read a lot of back and forth about honing cylinders when re-installing pistons. Some say do it, it helps re-seat rings, some say don't that it's all lies. Thoughts?
I really just wanted to get some opinions from you guys as to whether or not I should dig into the bottom end too. Again, there's no indication thus far about needing it but I don't want to be kicking my own a$$ later since the engine is out already!

 

http://www.xjbikes.com/Forums/viewtopic/t=46955.html

 

I wouldn't touch the bottom end if the compression test is normal. Actually, I wouldn't have even taken the engine out, but you're not me. If you have the time and energy, do it. I would never want to work on that unless my compression test fails.

If I start, who knows if I would even finish the job. I would get busy doing other things and forget about it.

That may also be due to only having one bike and I want to ride.

 

there's a chain guide in there that likes to get old and chip off.
look at the fingers on the shift forks for ware.
seals on the crank ends.
read this, xj's sometimes do this too
http://www.xs11.com/forum/showthread.ph ... t=gear+fix
if the shift forks are worn bad, read it twice. search there for second gear fix,
lots on the subject.
get the goop out of the oil pan too

 

okay, thanks guys! Anyone else care to chime in with opinions of the usual suspects?

 

How many miles on the bike?

I would have just done a valve shim clearance check, cleaned the carbs and be busy with brakes and tires, then go for a ride.

As far as honing......if you're replacing rings,gap the rings and hone the cyls. If you've mixed up your rings, gap the rings and hone the cyls. If you haven't removed any of the rings, there's no need to hone the cyls, because the rings are already mated to their paired cyl.

I won't make any comments about a perfectly fine bottom end--------

Dave F

 

50K miles. When I purchased the bike it had 2 pod filters on cylinders 1 and 4 and no filters on 2 and 3. I don't know how long or if the bike was run in this condition. I have to assume yes. So I am going through the engine and freshening it up. Replacing all the seals and gaskets, doing a valve job, shims all that will be done. I've already torn the bike completely down for my build, cleaned and rebuilt the carbs, replaced wheel bearings, steering bearings, brakes, and front tire. Will be replacing brake lines as well.

Since I already have the engine out and it's 31 years old and has 50K miles I might want to go ahead and replace this.... or inspect this... or the XJ has a common issue with this... like Polock pointed out the chain guide and shift forks.

So feel free to comment on a perfectly fine bottom end!

 

If:
-it has THAT many miles
-you already have it torn down THAT far
-you're already doing THAT much
-you are diving in deep

then yeah.....tear it down the rest of the way, and as you put it back together, freshen everything piece by piece.

It may take awhile, but you'll be doing a ground up restoration and you'll have a beautiful specimen to ride, appreciate, and show off. Heck, you may even get a trophy for it!

That's how I ended up getting my little collection of trophies.

Good luck to you!

And yeah, a nice clean tight 32yr old bottom end could really be something to behold.

 

This is not the bottom end discussion I was hoping it would be.

Or maybe it was!