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Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 10:35 am
by karl pa
I used Blue Devil pour n go oil stop leak on my T250 with success, first i would fill the crankcase to the top to check for leaks,if it holds the level good,I would drain some off but keeping seals submerged,spinning crank occasionally it is much easier to drain with the engine out of the frame,you just dump out,not sure if T350 has drain plugs under crankcase.

Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 10:43 am
by karl pa
Alan H wrote:The crank seal between the transmission end of the crank and the points cam takeoff can be changed without stripping the engine completely.
Can this seal be replaced,I thought on a 550 it was behind the main bearing that is held in by the c-ring.
Sorry to take over your thread.

Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 10:43 am
by Alan H
GT500-2stroke wrote: Also, How do I remove diesel fuel after soaking?
Till what level should I fill in diesel fuel in crankcases?

Thanks.
1. Tip the engine upside down.
2. It needs to be higher than the highest bearing.

Cover the big ends as well as the crank bearings and seals. Turn the engine over slowly for a few minutes, several times.
It does work - I've done 3 engines like this now.
Oil all bearings after you've drained the diesel. It'll smoke really badly and you may need a squirt or 2 of easy start initially, but you'll see the house eventually and the bike should be ok then.

See here - http://www.kettleclinic.co.uk/kcforum/v ... 490#p57490" onclick="window.open(this.href);return false; towards the bottom of page 1 for a full description of how to do it.

Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 10:45 am
by Alan H
karl pa wrote:
Alan H wrote:The crank seal between the transmission end of the crank and the points cam takeoff can be changed without stripping the engine completely.
Can this seal be replaced,I thought it was behind the main bearing that is held in by the c-ring.
Sorry to take over your thread.
That's the one in the clutch case that has the C ring (2 bearings and 2 seals as well.)

See my last couple of posts here - http://www.kettleclinic.co.uk/kcforum/v ... wig#p87891" onclick="window.open(this.href);return false;

Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 11:09 am
by karl pa
I think on a 550 the only seal that will pull transmission oil into the engine is the one behind the main bearing with the c-ring
Blue devil seal repair is a conditioner,to help soften the rubber

Re: 1972 T350: Need help on rebore

Posted: Sun Nov 25, 2018 12:47 pm
by Alan H
Ahhh, bugger. I thought that seal was outboard, like at the other end behind the alternator. Drat and double drat, Muttley!
With the smoke out of tbe RH pot, that seal is definitely toast.
Looks like a complete strip when I've done the other 550 resto.

Re: 1972 T350: Need help on rebore

Posted: Thu Dec 20, 2018 8:59 am
by Vintageman
I'm late, but d have experience on Suz twin.

smoke: Usually its center seal, dried and not sealing very well. One lip does not have spring around for tight seal.. poor design IMO.

If your crank is good so don't feel like rebuilding, soak seals in modern reseal like Blue Devil or ATP-205.

I hate the crank for I think big end bearing too small. If you plan to use bike, have crank rebuilt and at a min replace big end pin and bearing. Again inspect your crank. What's the mileage on it?

Boring: You may be able to bore up to 2.0mm. There used to period wisecos that are 2.0 (P8s). Paul Miller has some new custom Wiseco 1.5mm at times. There is a post here somewhere if you go above 1.0 bore the piston hits case or something but easy fix. I have seen some T350/305 cyls where the intake port divider has thin area due to casting flaws. Inspect for thin spot. Else OK.