Yamaha XZ550 rebuild

[r97]

Gaskets and parts for bike engines are sh!t expensive, I was going to redo the head on my 600, but a new gasket set was over 150, and I had to buy a starter, second hand for 50! very expensive.



There Must be bearings, plain bearings, you wont notice them, just thin pieces of high grade steel.

LOL, tell me about it with the prices! Normal go kart engines make are just so much simpler.

I'll look again, but as far as I can tell there are the aluminum cam brackets (not sure of technical name), the cast iron cam, and then some huge oil passages. No roller, needle, or ball bearings, not even a bushing. The cam is the bearing.

Gonna try to get an impact wrench, and some liquid wrench today.

 

[r97]

Ok, I sprayed a bunch of liquid wrench in there. Good news is that I give it a 10% chance of doing crap, bad news is I now have liquid wrench to clean out of the engine if I can't get those bolts off!

 

[Bluethunder3320]

once you get it running in the kart it would be a good idea to change the oil again.

have you tried putting a long steel pipe over your ratchet

 

[Rustydog2010]

Have you tried putting a long steel pipe over your power bar?

Fix'd it for ya.

 

[r97]

Yeah I will change the oil again, might not reuse the stuff I took out, looked kinda dirt already. Talking about oil, the drain does a very bad job at draining the oil, I wasn't expecting the engine to be completely dry, but I wasn't expecting the huge pool of oil on my bench either!

I have used a cheater bar already (don't like the idea of it, but I'm scraping the bottom of the bowl). Liquid wrench hasn't given any results yet, will try again tomorrow, but then I'm looking for an impact driver.

Power bar? Wish I had one of those right about now!

 

[Bluethunder3320]

what is a power bar? breaker bar?

oh yeah, i had a cheap socket set and the ratchet broke the second time i used it. so i just welded the crap out of the part that ratchets. now i have a breaker bar. woot

 

[Rustydog2010]

what is a power bar? breaker bar?

oh yeah, i had a cheap socket set and the ratchet broke the second time i used it. so i just welded the crap out of the part that ratchets. now i have a breaker bar. woot

Yea, tomato - tamato. Hmm maybe that doesn't work well over the internet.

 

[r97]

Ok, well after modifying some tools, and getting more leverage I finally broke those nuts off! Here is tonight's progress. As of now I have removed the heads and the cylinders. The gaskets are all goners (gasket set here I come...), but everything else looks to be in great condition. The #1 cylinder has a bit of varnish(?) on it but nothing bad, should be able to clean it off or just leave it. Best of all though is that both cylinders have a faint, but just noticeable cross hatch pattern on them! I guess this bike must have been rebuilt (at least the top end) before it got too much use (could have been 20yrs ago for all I know).

P.S. Sorry for my lack of picture taking skills.

 

[r97]

Ok, here is the work I have been doing lately. I had to buy a puller to remove the flywheel (Nothing happened and then it jumped 2ft from the engine!). I also need a crowfoot wrench for the crankshaft nut, but that will take a few days to get here.... I'll try to sort out the clutch tool, paint, gaskets, torque wrench, etc in the meantime. If my shop wasn't so occupied by this engine I would work n the minibike.

EDIT: Made in Canada oil filter

 

[r97]

More pictures:

 

[r97]

Ok, so I'm now at the point of splitting the cases, but as you might guess that isn't happening too easily. I'm pretty sure the dowels are rusted in, I have sprayed liquid wrench all around the mating surfaces and in the bolt holes. I'm going to let that sit for tonight, then get back at it tomorrow.

Anyway, aside from that I have been trying to slowly and carefully coax the halves apart with a rubber mallet, and a knife (I'm being careful not to ruin the mating surfaces). Any tips I should know about for doing this? Or should I just keep slowly working at it? The cases haven't separated at all... zero. And yes, all the bolts are removed. My research hasn't shown anything about these bearings being a press fit either.

Thanks! Once I get the cases split it should be smooth sailing, just lots of cleaning and torquing of bolts.

 

[mrfreyguy]

Try to find any thing sticking off of the case to hit with that rubber mallet. Make sure that the cases come apart evenly or you could damage some of the engines components.

 

[fowler]

if there isnt anything then try a chisel

be very careful and dont hit too hard
try to get the chisel in the gap and seperate it
its hard to explain but if u are careful it works

try to get it a little apart then u can pry it open with a pry bar
or screw driver

id be doing anougther bolt check
look for resesed bolts in holes full of grime

 

[r97]

Yeah that's what I have been doing, but judging from the struggle I went through to get the side covers off... that's not going to get the cases apart. I'll keep trying though, it's gotta come apart eventually.

 

[r97]

if there isnt anything then try a chisel

be very careful and dont hit too hard
try to get the chisel in the gap and seperate it
its hard to explain but if u are careful it works

try to get it a little apart then u can pry it open with a pry bar
or screw driver

id be doing anougther bolt check
look for resesed bolts in holes full of grime

Yeah, I suppose I could go buy a chisel. Would that be much better than a knife? (I have been tapping the knife with a hammer.. nada).

I'll look around for bolts and other things that could prevent it from separating, but I have removed the same number of bolts that the service manual specified.

 

[fowler]

some one else will have to secify if this is allowed on an engine
but if a hydrolic pump wont seperate then u put a bit of heat into it
that will break the seizure

but of couse it stuffs all the seals and gaskets
and the paint

 

[Bluethunder3320]

sounds like youre already deep into it... but why do you need the case apart? maybe its telling you something. to not take it apart... lol

 

[r97]

I would consider heat, but it still has oil in every nook and cranny. I doubt mom wants that in the oven .

Hydrualic pump? Please elaborate, how would I use that to seperate the cases?

Yeah, only things left are the transmission, shift drum, crankshaft, balancer, connecting rods, and the middle gear. After that its just the block, and bearings. I will see if I have any pics.

EDIT: It has sent me a message saying not to take it apart several times now. All have been ignored, struggled with, and overcome. Worst thing so far was that I had to remove the left side crankshaft nut... with a drill. I had to use an off set wrench to get at it, and because it was off set it would slip off before I could put much torque into it. Pics in a bit if my computer will cooperate.

 

[fowler]

by heat i mean an oxy torch

a hydrolic pump is well a pump for hydrolic oil
earthmoving machinery rely on them
so when ever we do rebuilds we recondition the pump to reduce later issues
no relation to u just describing other applications

if u really get frustrated i can get a 20 tonne hydrolic press to rip the case apart

 

[r97]

LOL, I'm well aware what a hydrualic pump is. I was just under the impression that you were using one to seperate the cases. No 20 ton shop press for me.

I don't have an oxy torch, and to avoid warping I belive I would need to heat the entire casting at once. I.E. an oven.