Swing Arm/ Engine Removal

Hello,

I haven’t been around in a while, and the help you all offered before was invaluable. Sadly after rebuilding the carbs, and working all the bugs out of the electrical, I finally went out and bought a compression tester to find cylinders 2,3 were shot. So with that the engine is getting pulled out, and the bike broken down for parts. The bike is a 83 KZ750 shaft drive with duel disc breaks on the front, I think it might be a LTD?

Where I have run into a problem is I can’t for the life of me get the engine out of the frame, I got all the motor mounts out and the only thing the holding the engine in is the shaft drive. So I want to drop out the swing to lift the engine out. It seems like it either that or pull of the clutch and I don’t really want to go that way.

I got the nuts of the swing arm, but it doesn’t seem to move left or right, and I whacked it a few good times with a hammer to no avail. Thanks for any advise you may be able to offer.

~William

William wrote:

...bought a compression tester to find cylinders 2,3 were shot....

Lack of proper valve clearance often causes loss of compression. Were clerances checked?

Was compression tested with wide open throttle?

Was a teaspoon of fresh oil added to low cylinder and compression re-tested at WOT?

Has a leak-down test been performed?

Hoping to possibly save the time, trouble and expense of a teardown.

You don't need to pull the motor out to fix the problem. Pull the head and cylinders. get the bores checked and honed, get a set of new rings if everything is within specs. Maybe get a vavlve job and you should be good to go.

I don’t know how to check value clearness, so I just pulled off the exhausts and watched the move around when I held the starter on and they all seemed to be doing about the same thing. As for a leak down test, I have no idea what that is.

Oil thing only slightly changed the results, 1 and 4 were running about 90 PSI, 3 ran 0, 2 ran 30, 2 would get up to 60s with the oil, but the other cylinders remained unaffected. I checked them all with no throttle at all.

As for the break down, I went to a shop to see how much to get the cylinders bored, and the guy said 5-600, but if I brought him just the engine he would only charge 300. It was also just so I could take it apart and put it back together. The KZ wasn’t so expensive, so if I kill her its not as bad as one of the other bikes. Kind of a personal learning experience. And if I fail lots of cheap parts for the community. Thank again for the help.

$600 to have the cylinders bored? :ohmy: I think the average price is around $50 a jug. I would think about finding another mechanic or study the books and do the work yourself. I'm not sure why he would charge you more to do the work if you brought the jugs in to him. Sounds fishy.

hey don i think the 600 is full labor to tear the bike down bore it and reassemble

William wrote:

...Oil thing only slightly changed the results...checked them all with no throttle at all....

Compression test with closed throttle is invalid (a common mistake ). Compression test should be done with ignition turned off, transmission in neutral, and throttle held in wide-open position.

Thinking lack of compression likely due to lack of proper valve clearance -- and perhaps NOT rings. Checking valve clearance is relatively easy. With engine cold, remove valve cover and use feeler gauge. .

Correcting clearances by adjusting shims is more involved, but routinely done without removing the head.

Leak-down test is pumping air-pressure into the cylinder through a spark plug hole, then listening to where it escapes. Leaking exhaust valve = escapes through exhaust (may listen and hear at end of muffler). Leaking intake valve = escapes through carbs (may listen and hear at carb intake or air box. Leaking past rings = escapes through crankcase (may listen and hear at crank case vent). But often, setting valve clearances to specs resolves a low compression problem.

A good shop repair manual is essential.


Edit: Ignition switch is turned on to spin engine over using starter motor instead of kick-starter. Best to have all sparkplugs removed.

Post edited by: Patton, at: 2007/09/25 02:34

Yes it was 600, to bring them the dead bike, and have them do the cylinders. I am positive at this point something is wrong with the compression as it’s the only thing left that it could be, good spark, good carbs, but no running, only time I have even gotten a hick-up was with allot of starter fluid though the carbs. The blew out the back, so it may be that the timing is backwards or really far off.

However at this point in the project I really need to know how to get the swing arm off as I got the engine sort of jammed in their now and can’t get it back where it was either. I took the nuts off either end of the rod it pivots on. It doesn’t seem like it wants to move. I think its one shaft running though the whole thing but now I a thinking it may be a two-piece shaft to account for the drive shaft. I will go to the shop on Wednesday and order up a repair manual. I didn’t think a bike would be such a big jump from go-carts. I was wrong.

So again, help with getting the swing arm off would be greatly appreciated still.

~William

William wrote:

...am positive at this point something is wrong with the compression as it’s the only thing left that it could be, good spark, good carbs, but no running, only time I have even gotten a hick-up was with allot of starter fluid though the carbs. The blew out the back, so it may be that the timing is backwards or really far off...will go to the shop on Wednesday and order up a repair manual.

Backfiring through carb may be caused by insufficient intake valve clearance.

Manual will explain ignition timing procedure.

Could initially use static method (engine not running) to get pretty close; then use strobe-type timing light on running engine (dynamic method) to assure spot-on ignition timing and which also allows actually seeing the advancer unit move back and forth.

Am believing even with perfect pistons in a perfect bore with perfectly sealing rings, all the same problems heretofore noted may still exist (i.e., poor compression, backfiring through the carb, failure to crank, etc.) due to inadequate valve clearance. Meaning gap is insufficient and preventing proper closure of valve against its seat in the head.

Good Luck with whatever you decide.

I remember on the 1000's there is a pin you have to push in with a really small screwdriver to get the shft disconnected. I has been a long time since I have taken one apart.