Trailfire center crank seals

ND1 · Post by **ND1** » Sun Jan 14, 2007 8:17 pm

I need some insight on the center seals on Trail and Liquifires, I have every manual but they dont go into detail on them.

Can you tell if they are bad other than a pressure test
How much play can they have
Where can you get the outer o-rings
Whats with the o-rings on the bearings
Is there a replacement for the center seal, I seen a 2-piece model in a catalog, does that indicate you can replace it without tearing apart the crank
And last; how do they work, is there o-rings on the inside too

my motor is torn down for a simple repair, but now i am stuck on the seal issue, all 7 of the o-rings split and fell apart when I removed the crank

anyone know the facts on this?

Thanks

ND1 · Post by **ND1** » Mon Jan 15, 2007 10:10 am

That works for me, lets say I find o-rings, how would you even get them on the center seal and bearings.

WatertownBob · Post by **WatertownBob** » Mon Jan 15, 2007 10:40 am

Nd1 where are you located. I grew up in Bismarck and now live in Watertown. Don't see many John Deere sleds in this part of SouthDakota.

Bob

ND1 · Post by **ND1** » Mon Jan 15, 2007 8:03 pm

20 miles East of Fargo

Rodimus Prime · Post by **Rodimus Prime** » Tue Jan 16, 2007 8:40 pm

number 1 center seal may look okay from outside but can be pluged or full or tarnished fuel or aluminum.. best method is to take crank apart clean and replace parts as nessary.

center seals are actual not hard to diagnose... if your engine idle is erratic and is not fualt of carb center seal is not functioning.. can also cause minor starting problem.

chances are that if orings on ALL bearings are bad bearings are getting old and worn out.

its usually 100 dollar or less to get crank rebuilt with new bearings and cleaned or new center seals.. its a small investment towards knowing your engine is good.

i have also seen worn 2 part seals. usually from center tilting when engine is put together. 2 part centers sometimes come with alignment pins for two halves..some dont. i have a box full of deflection seals for different engines and crank sizes in shop.

ND1 · Post by **ND1** » Tue Jan 16, 2007 10:58 pm

I did a little research today and found that the o-rings on the bearings are to help with the vibrations, and are not neeeded at all. they were not bad, they just split when separating the case, the bearings are in good shape, I have to no when to say when so Im going to reinstall the crank after a gasoline bath.
As for the center seal, the motor ran great before tearing apart, I was just concerned about the design; been working on too many CCW's!
Thanks for all the info guys.