Fresh(ish) rebuild, smoked out the neighborhood

xjwmx said:
I just now realized it's a 750 kit. There's more than one thread over the years about them smoking,

http://www.xs650.com/threads/oil-in-cylinders.50128/
http://www.xs650.com/threads/normal-compression-test-on-new-750-kit-w-cam.1265/
Click to expand...

retiredgentleman said:
That's a very good point xj. Oh oh, another Mikesxs part that is turning out to be crap:doh:
Click to expand...

2 threads in 7 years about smoking builds from MikesXS 750 kits..............

Tounge in cheek.

if i remember correctly he has sold 3 kits so that makes 75% of his kits sold that are defective...........yea bloody mikes ripping us off again........ban mikes.......its all mikes fault...........

hang on heiden tuning sells the same 750kits..........maybe what??? he has sols three as well........down to 33.333333333% now...............

Come on you guys there a hundreds of those kits out there, not only on the road but used in racing bikes as well........ statements based/hinted on person feelings not on fact
 
ok ok settle down boys. I know the colored history of mikes. Between both of 75's Ive spent quite a bit of money at Mikes. I haven't had an issue yet. Lets try to keep it on point here.

And I seriously appreciate all the advice and help, and links to threads that I read so long ago I forgot all about them. Seriously. This place the best resource that us fools that love these damn bikes have.
 
litertrider, not getting at ya just some thoughts............

It sat for 5 years after rebuild/assembly....used heaps of lube....

all that lube has congregated or sat and probably hardened to the surfaces or what not........

Did you lube the bores before turning over the engine for the first time after 5 years..............

on start up, did the rings, especially oil rings, get a chance to do their job, (again thinking maybe they got stuck in the piston if the lube dried a bit).......

think about procedures and what was done to deviated from them.............first post said it smoked on start up after a rebuild.........now we know it sat for 5 years before first start up.........any deviation from normal practices can be a source of a problem.....sitting for 5 years could and does in certain circumstances create a problem........

worst comes to worst i would lift the head, raise the barrels enough to get a gauge on the hone marks, take off the barrel and check the ring alignment, or a broken oil ring..........maybe do another light.....light......hone and reassemble.....

If you are confident the rings are sound, take the bike for a proper break in run, do the proper procedure , come home let it cool down, tighten the head take it for another run...........

keep your mind open, don't commit your self to a problem before assessing the thing as a whole
 
Thanks Skull,

Yeah, I know there could any multitude of things going on. I'm just trying to understand what I should be looking for, and then investigate and eliminate each of the potential issues in a kind of methodical manner. I've gotten a ton of help so far.

I guess I was mostly just wishfully thinking I wouldn't have to take the motor out and pull it apart. Kinda of like when your car stops making a funny noise, it means it fixed itself.
 
lidirtrider said:
Yeah, I know there could any multitude of things going on.
Click to expand...
There are really only two possibilities and only one realistic one. The top of the cylinder isn't flat. Nothing else would pass so much oil that it would be dripping out the left exhaust flange. And since it is the left, if it's on the side stand then gravity is probably helping it along.
 
Was the head done evenly and in the proper increments up to 30ft lb..........uneven tightening of the stud nuts will give you the same affect as a warped head........

Lots of variables.....
 
TwoManyXS1Bs said:
Was any porting work done on the head?
Click to expand...

Nope no work done to the head

650Skull said:
Was the head done evenly and in the proper increments up to 30ft lb..........uneven tightening of the stud nuts will give you the same affect as a warped head........

Lots of variables.....
Click to expand...

Yes, at least as far as I can tell. Did it following the pattern, in 10 ft lb increments. Re-tourqued twice, seems to have helped (a little) but now I can see a small leak from the head gasket on the left cylinder. :cussing:
 
Well, that's bad news !.... head gasket leaking oil means the head has to come off. gasket replaced and ( i use copper coat sprey on both sides of the head gasket) and put it back together and re torque it in sequence run it a few minutes then retorque it again then after 50 to 100 miles re torque again....
that seams the only way out to me !
......
Bob......
 
xjwmx said:
There are really only two possibilities and only one realistic one. The top of the cylinder isn't flat. Nothing else would pass so much oil that it would be dripping out the left exhaust flange. And since it is the left, if it's on the side stand then gravity is probably helping it along.
Click to expand...

It's not that the oil is leaking out of the flange, its actually coming out of the end of the exhaust pipe. when the bike is running it pumps white smoke out of both pipes, and kind of spays droplets of blackened oil out. I mean I guess its splitting hairs, since either way, oil is still entering the combustion chamber.

Since there is still a small punchlist of items to be completed on the bike, I think I'm gonna try to finish everything else, (wiring, few minor things to fab, etc) and once its all buttoned up as if its 100% ready, I'll pull the motor out. Seems less daunting in my head that way. Then I can tear it down and methodically inspect and repair whatever needs to be done. At the very least, I know I need to replace the head gasket.
 
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Please add/edit/critique my thought process on tear down/inspection:

Obviously the motor will be out, and all the ancillary bits that need to be removed to open the top end will be off (pamco/advance mech/etc). So upon removing the head cover:

#1 Remove cam/bearings, inspect cam seals, clean/inspect all mating and sealing surfaces
#2 Remove head, remove valves, inspect valve seals, guides, and guide rings, replace as needed, lap valves as needed, clean/inspect all mating/sealing surfaces, check, err...flatness? of head to cylinder mating surface
#3 Remove cylinder, inspect cylinder bore, hone as needed, clean/inspect cylinder to case mating surface
#4 Remove piston rings, inspect for proper tolerances, gap, replace as needed

So cover the cleaning and inspection part of it, i think. Any input on any of that? Like, how and what exactly I should be checking.

I again want to thank everyone that has been commenting here, it's been very helpful so far. I know a lot of these answers may already exist somewhere on the board, and I'm sure I've read most of them, there is just so much to go through these days.
 
You seem to have covered everything. I don't think I'd pull the valves all apart unless I tested them first for leaks and found some. If you didn't do them the first time around then sure. The guide seals most likely need replacing.
 
5twins said:
You seem to have covered everything. I don't think I'd pull the valves all apart unless I tested them first for leaks and found some. If you didn't do them the first time around then sure. The guide seals most likely need replacing.
Click to expand...

How should I test the valves for leaks? I actually just replaced the valve seals using board member Grepper"s guide to doing it with the engine still in the frame. I just figured if I have to take it all apart anyway, I'll just replace them the proper way to ensure they are 100%

I guess a leak down test before disassembly would be smart thing too?
 
Personally i think torquing a head gasket requires more than 3 rounds of 10 ft lb.........i think it is to much each bite.

I would do less at a time and more of them and the last couple...........maybe, 8-6-5-5-3-3.......after an initial snug up using the criss cross sequence
 
Check the lengths, tightness, and seating depths of the cylinder's hollow dowels. Long ago, would often find hollow dowels with nicks/gouges from aggressive removals with diagonal cutters being used as leveraging/removal tools. They don't fully seat with those nicks. One way to test is to fit the head atop the cylinder, without the head gasket, see if it seats fully...
 
I like using my 24" framing square or my Level to check for flatness just lay it across the area and see if there are any gaps
the head can be checked as well as the cylinder top this way..... I will defer to the experts on how much tolerance there can be and still be good to go..... but I know it's not much if you can see light under the framing square ( or other known flat surface) then you have a gap.
the gap can be measured with a feeler gauge to see how much the part is out of level or warped... this can be compared with the parts tolerances to see if the part needs to be shaved to bring it back into specks!
f.w.i.w.
Bob.......
 

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