Stock Bore JE Piston

[2000ex]

I am awaiting my shiny new stock bore JE 10.5:1 piston as well as an XR400 cam. Does anyone run this particular setup?

I was going to go the 416 route, but thought the 16 cc would not make that much difference. (all in the compression ratio). I currently running a White Bros E Series, modded airbox, choke removed and a 165 main. I am having high hopes for some new found HP.

I'm thinking of running the same exact setup so I'd be VERY interested also.....or any imput at all would be great,,,

[2000ex]

Rico,

I asked the guy at JE if there was any choice in comp ratios for the stock bore and he said, no. I really dont think I will be compromising much HP with the 10.5 vs the 10.8, and the motor should run cooler than the 87mm as well.

I was hoping for the 10.8:1 but that was only available for the overbore.

Come on, I am sure there are others here running a high comp stock bore.

[400exRacerX]

i want to run a high comp stock bore. b/c i dont want to run into all the problems of boring and honing the cylinder and worring about having engine problems with sleeves cracking,seizing bearings etc.... with stock bore high comp you will gain some more heat but not as much as a overbore, the power gains will be nice too with a cam. but the problem is right now i dont have the money for this mod because i just cracked my swingarm 550$ need new a arms, brake lines, and shocks.:grr

2000ex,

I recently installed a .020 Wiseco 10:1 piston in a friends machine with the stock cam and a White Bros. box. There is definately a noticable difference in power. Before, our quads were always about dead even. Now he consistently beats me. As well, from a "seat of the pants" feel, you can definately tell a difference.

Given that you're going to 10.5:1 and adding the XR cam, you'll have to notice impressive gains. Please post results when you are done as I've been planning to do a similar mod. I have a friend who has a Superflow dyno on order, and I'm waiting to get a run on it with my current setup as a baseline so I can say for sure what the difference is with the mods.

Did you call JE directly for your piston?

Dana

[2000ex]

Bumpy,

Thanks for your response. I have been a member of this site and Gabes list since pretty much their inception, but rarely if ever post.

Seeing and reading my fair share of posts, I think this combo should yield great results. I love the reliability of the machine, and really didn't want to tear it down and bore it, etc unless it was necessary.

Yes I called JE directly, they were very friendly and helpful. I cannot wait to have that little shiny new slug at my door.

[NVR2L8]

2000ex: I used to ride with someone that ran the same set up that you're considering. The stock bore high-compression JE piston and XR400 cam made a significant difference in power--up throughout the rev band. What really woke up his engine after these mods though, was when he added a 39mm FCR carb. After bolting on the carb the engine just seemed quite a bit more powerful everywhere, as well as extremely responsive.

[2000ex]

I have heard nothing but great things about the FCR. I think I am leaning towards running some triple rate Elka's before I spend more $$ on go fast parts.

Shocks are perhaps the best investment in being able to go fast and pummeling those pesky Raptors through the woods.

:grr

[inacoma91]

This sounds interesting. I was planning on doing the 416 kit in the future .........but if you get pretty good gains from this then i might consider doing this instead guys!!!! So how much is going to cost to get the JE piston and a XR cam??

[2000ex]

The cam from service Honda was $120, top end gasket kit $26. I believe the piston was $136 plus shipping. Total of $282.

I am hoping for more HP for my dollar than the pipe I am running which was around $220. From what I have read over the past year I doubt I will be disappointed. I will keep you posted on the results once I get her set up and dialed in.