inner clutch hub threads stripped

[BLUDGEONER]

the water jacket O ring could be undersize? the left cover gasket can be fatter and then the W/J |O ring then defo becomes undersize!

can cooland come out of the little front hole or is that blocked?

Taffy

Funnily enough I used slightly oversized o-rings last time I put it back together. 17x2.65 water jacket o-ring instead of 17.3x2.4, and 10x1.8 balancer shaft o-ring instead of 10x1.3. Maybe go even bigger on the WJ one next time? Didn't notice any coolant coming from the little hole - all my concentration was on the sight glass watching the oil go milky....

 

[BLUDGEONER]

I hope it's those but it Can be liner o rings or cracked liner. Look for crack on the outside of the liner just under the flange at the top

Also when you have the clutch cover off Check the depth of the little o ring slot on the left hand crank case then measure the Thickness of the o ring. You would like to have about 1mm crush. Sometimes the groove is way too deep.

Definitely have a look for those tomorrow. Might even be able to face taking the clutch cover off.....again!

 

[bushmechanic]

Cool. I forgot to add the clutch cover gasket reduces crush of that o ring as well

 

[BLUDGEONER]

I hadn't fully considered what you said when I responded earlier - I'm not ready for a full strip down and rebuild on this engine! Been planning to attempt it eventually (with guidance). Going to see if I can get a 17x3 or even 3.5 o-ring in there and hope that cures it. Reckon I may be able to ease the casing back far enough to swap that out without pulling the water pump seal over the edge, must be worth a try. If all else fails, what's the availability like on a good used liner for a 550?

 

[Taffy]

if you use the kickstart o ring like we sell then that would do. give it a little stretch first and then cover on quick.

Taffy

 

[BLUDGEONER]

Ok, stuck a fatter o-ring in there and still no joy. Cracked liner or liner o-rings as mentioned seems the likely culprit then?? What are the options for diagnosing this without tearing down the engine please? Borescope? Leak down test? Any advice much appreciated.

 

[Taffy]

well I block the jacket hole with a little rag etc around my air jet and pump it up. you want the airline pressure to be low. I just turn the electricity off and run the tank down. takes about a minute.

but at the end of the day, once it isn't in the left cover it's engine down.....

Taffy

 

[BLUDGEONER]

Seems I'd best get cracking and strip it down then - had to happen sooner or later, but timing is bad. Thanks all for the help so far. I'll keep this updated with my findings....