SX/SXi/SXi Pro 750 sxi big pin rebuild

[Captain PegLeg]

After putting almost everything new i can think of trying to fix my kawi, i took it to a shop for diagnosis. He said i need to main seals in my crank. Said it had a bunch of gunk, like burnt oil and crap in the flywheel cover and 120 lbs of compression w/ my milled head on. So i think i am gonna tackle the mainseal job myself. How hard is it to do? I have had the motor torn down to the cases, just never had them apart... any ways/techniques to make this job easier?

 

[sflsurfrider]

beer.

 

[Captain PegLeg]

I hear ya.

 

[gorilla]

just remove the whole motor.
then remove the coupler 1st, then remove the flywheel.
turn the motor up side down.
crack the crank cases apart.
clean up the bottom case + top case the best you can, and install your new seals.
use 1211 on the bottom case, then put it back together !!!

you dont have top tear down the top end !!!

good luck

gorilla

 

[jondotcom]

just remove the whole motor.
then remove the coupler 1st, then remove the flywheel.
turn the motor up side down.
crack the crank cases apart.
clean up the bottom case + top case the best you can, and install your new seals.
use 1211 on the bottom case, then put it back together !!!

you dont have top tear down the top end !!!

good luck

gorilla

Do you really have to split the cases? Pretty sure you can change both front and rear seals without all that work. Time to look at the manual

 

[madscientist]

you have to be joking right!! ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

the cases will have to be cracked to do the job properly.

use a piece of rope fed through the plug hole on 1 of the cylinders to keep the motor from spinning, and try to do the coupler and flywheel while it is in the hull for leverage you will need it.

kris you can call me if you need more support.

 

[Captain PegLeg]

I need you # justin!

 

[Waternut]

You've probably accomplished already but I would think if you have 120psi in the cylinder, your battery isn't charged fully or your rings are shot. The crank seals is a seperate issue. Both are really easy though.

To just remove the cranks seals the easiest solution is to remove the flywheel and coupler. Use a rope in the spark plug hole to accomplish that. Then turn the engine upside down and pull the bottom of the case off (I sat it inside the trailer bunks). You can just lift the crankshaft up enough to slip the seals off and on. Then go get some Yamabond/hondabond/etc. to seal the cases back up. The hardest part is getting your nerve up and scraping off the old sealant.

PS- Do a pressure check on the engine before running it again!

 

[Captain PegLeg]

You've probably accomplished already but I would think if you have 120psi in the cylinder, your battery isn't charged fully or your rings are shot. The crank seals is a seperate issue. Both are really easy though.

To just remove the cranks seals the easiest solution is to remove the flywheel and coupler. Use a rope in the spark plug hole to accomplish that. Then turn the engine upside down and pull the bottom of the case off (I sat it inside the trailer bunks). You can just lift the crankshaft up enough to slip the seals off and on. Then go get some Yamabond/hondabond/etc. to seal the cases back up. The hardest part is getting your nerve up and scraping off the old sealant.

PS- Do a pressure check on the engine before running it again!

I'm running a head that supposed to have 190 psi! I believe its low! HAHA, plus its got a brand new top end and hone.

 

[Waternut]

Yeah I'd charge that battery. Crankcase leaks will only alter the fuel mixture, they aren't going to lower compression. I know because I tried everything when I first bought my 750 and compression was normal but I couldn't tune the carb...turned out to be multiple air leaks.

 

[FlightRisk]

What's the best way to test the crankcase for air leaks?

 

[Tjwaterhoon]

After putting almost everything new i can think of trying to fix my kawi, i took it to a shop for diagnosis. He said i need to main seals in my crank. Said it had a bunch of gunk, like burnt oil and crap in the flywheel cover and 120 lbs of compression w/ my milled head on. So i think i am gonna tackle the mainseal job myself. How hard is it to do? I have had the motor torn down to the cases, just never had them apart... any ways/techniques to make this job easier?

After my ski reved out on the flush hose I knew something was up checked the compression 120 and 150 so something wrong, intake was atleast a turn loose on each nut, oil residue in behind the flywheel, so crank seals aswell, took of the cylinders loose rings almost fell of the top of the Pistons, around 4 to 500 ml of fuel in the crank case, Yes a few issues not too bad tho easy to freshen up, new crank seals, crank has to come up or out there is a lip holding them in, rebore hone and new top end, redo the carbies and good to go probly 600 dollars