JE Pistons bad???

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aroracer72 · #1 Post by **aroracer72** » Thu Sep 28, 2006 2:14 pm

Soo i hear JE pistons dont last more then around 10-12 hours???......if this is true then this really sucks because i cant afford another darn piston and now i have nothing to ride for the one riding trip i had planned all summer. I have my motor out now and was gonna throw this piston in to bump up the compression to 13:1 to get a little extra juice in my ol beast.....but if its gonna wear out the wrist poin in around 12 hours then to heck with that...its pointless.

Please give me good news
Chad

by the way, this is a 450 piston for my 468 stroker....its got a falicon stroker crank and a 450cc cylinder.
Chad

wistech · #2 Post by **wistech** » Thu Sep 28, 2006 5:39 pm

We were thinking a chrome wrist pin might hold up . If you are going to use that piston it is an absolute must to clearance the sleeve to the piston.
Every JE ive used lasted between 1 and 10 hours before breaking in half or smacking the head from a worn out wrist pin.

azcannon · #3 Post by **azcannon** » Thu Sep 28, 2006 5:51 pm

has anyone tried warranty on them if its a known problem why wouldn't they acknowledge it?

haydug · #4 Post by **haydug** » Fri Sep 29, 2006 12:18 am

We should see pics of Chad's piston when he removes it. I would venture to say it has over 40 hours on it before I got rid of it, with no loss of power.
There is also a bike local with a JE that has around 50 hours now, and still running strong.

Hmmm, wrist pin, I thought it was the blow by that made them junk.

cannondale27 · #5 Post by **cannondale27** » Fri Sep 29, 2006 1:11 am

I cant think of anything good about them.I would like ANYONE to explain how a piston(aluminum) can chew into a steel wristpin with no wear on piston?Then there is the issue for some of us of cracking.Not going to get into a hour use argument.All I know is EVERYONE who had one that I have seen directly has had a issue.On top of that they struggle to make 50hp.Now I do know that other makes can have just as many issues with big bore pistons.They all can go at any time.But fact is the CP's seem to be holding up better among the same group who had trouble with JE's.

Canniboomer · #6 Post by **Canniboomer** » Fri Sep 29, 2006 1:50 am

I think those same JE's that were not making power were actually dragging in mis-manufactured sleeves, and pressing much harder against the wristpins.... I had one destroy itself in less than 2 hours.
If you watch the clearance, use the correct wristpin, and know the history of the sleeve you are using, you will likely be pleasantly surprised.... if you don't know the history, you might want to send the whole kit to Timbo for a good checking-out first.

aroracer72 · #7 Post by **aroracer72** » Fri Sep 29, 2006 1:53 am

Sooo basically if i wanna tear my motor down again in a couple rides just throw this piston in????....lol.......this sucks, i have the engine out, and i mean is there one reliable piston out there???....because while i have this apart might as well build it right.....i dont like building things weak or half arsed.

Soo all i heard is bad things,.........dont even dare use this piston??....or make quadruple shure the sleeve is clearanced and what else??..........im lost as to what to do here. But i AM glad i caught this before i had ait all together...that woulda made me all warm inside.....lol. Also doug is it a JE piston in this quad right now????.....cause as for power(im shure its due to low compression) its super slow....i used a bung and sensor to perfectly tune it and stock z400's and even 400ex's were keeping up/passing me on straights...yes its that bad...haha....but ive been told the compression will mostly cure this....cause my stock dale i had with just a pipe beat this. But im not dissapointed...just wanna get it right....and is it safe to use this piston???......is it maybe the higher compression combined with the JE makes things go all confuggled....cause right now this quad is running you said around 10.5:1 and its lasted forever.

Chad

Happyboy · #8 Post by **Happyboy** » Fri Sep 29, 2006 3:07 am

Eh, even with bad compression you should still whip the **** outta 400s. If you are really worried about the pistons I would get a stocker back in there and you would be fine.

The lack of power would be more likely caused by something else in this mix. Maybe the valve train somewhere. Valves have too much leakage or maybe cams are worn or out of time. I would look there first. Thats just me though.

aroracer72 · #9 Post by **aroracer72** » Fri Sep 29, 2006 10:46 am

Thats what i said....i should still be at least pulling away...it was embarrassing...ive had this quad almost a full season now and have ridden it approx. about 5 times.....its kinda useless. If it had decent power i woulda raced and been dishing out some serious whoopins....lol.

While i have the motor apart im gonna check the valve train for leaks and timing....i always do anyways.....soo hopefully i find something wrong in there.

But i still need to know what to do about this piston problem.
Chad

cannondale27 · #10 Post by **cannondale27** » Fri Sep 29, 2006 12:19 pm

The tight piston issue was taken care of right away after first few failures.The failures I am talking of happened after that with great fitting pistons.Some on shortrod Falicons will probably last forever since they probably only have 8:1 compression.