88 mm 11:1 400 ex piston safe ??

[parts eeter]

Is a 11:1 88mm piston from wiseco safe to use on a woods machine? I was told it will run hot and the sleeve will be really thin.I checked the service manual and the oem bore is only about 85mm. I really need feedback quick as I need to get my motor built soon.If this is a bad size I can get a 11:1 piston closer to the stock bore if it will help. I will jet rich to keep it cool and will not be advancing timing any over stock.The cost of a sleeve really isnt bad so I am not too scared but I dont want to ruin rliability in any way.Thanks for your help guys.....Oh yeah can I use the stock head studs with this piston or are the larger studs required??

[Colby@C&DRacing]

we recommend to sleeve the 426 piston kits due to the heat factor and the sleeve can be bore to a 440 also. If you don't want to sleeve it that is your choice I know many people that run them without sleeves your other option would be to go with the 416.

[400ex28]

I would just go with a 416

[underpowered]

i have an 88mm 11:1 piston on stock sleeve. been together for about 1.5 years now with no problems. runs cooler than a 440 will even with stock sleeve. id say go for it.

[parts eeter]

Thanks Tyler and C&D..,I have a couple of more questions.First off I really thank you guys cuz I am in crunch time for finishing this quad.First question is
1.If the big bore sleeves are better than stock why is the OD the same?? I thought the big bore sleeves had more material to allow for bigger pistons.If they drop in how is this any better??
2.I could really use a part number for the 88mm head gasket required and if C&D has it I will buy it from you no problem.
3.Is stock head studs ok to use on 11:1 88mm pistons
4.I have a magnum stage 2 cam thats never been installed but I dont want to mod the head in any way so is it stupid to drop it in with no valve train mods??I have been told that the 88mm 11:1 kit with the stock cam will be just like stock but better all over than I have now.I like the powerband and am greatly concerned to alter it in any way.I also dont want to ruin the head because I didnt prep for a hi lift cam before install.Please answer each question as I am really stressed and have dumped lots of flow into this quad and dont want to flub up now.Tyler how does your 426 kit compare to stock??Pros and cons?You guys are the lifesavers!!
:D

[Colby@C&DRacing]

A big bore sleeve is not the same OD as the stock sleeve. The cylinder must be bore to accept the new sleeve. We stock steel flex gaskets that will work for the 88mm piston . As for the magnum cam there isn't any mods required to run that cam. You will be alot happier with a piston and cam combo than just the piston.

[underpowered]

1. the big bore sleeve is a larger OD than stock, you actually have to modify you stock cylinder to accept the BB sleeve
2. PN depends on brand. i personally prefer JE, but there is nothing wrong with a wiseco. conact C&D and they can set you up with either one.
3. i ran stock for a while, but they eventually pulled out. i purchaesed new stock studs and instlalled heli-coils in the holes with no problems for over a year.
4.like colby said, the magnum cam is a drop in, just pull your stocker out and put this one in, no valvetrain mods required.

the cam adn piston work well together, you will get a gain with one or teh other but it will be better with both. i run a WB all around cam and love it. more top than a stage one but more bottom than a stage two. works great for trails and play riding. Pesonally i like this cam better than either of the hotcams. my bike was fresh when i bought it in november of 2004, had some time on it but not much. i have rode is about once a week, sometimes more since i bought it. the only problesm i have had is, the head studs adn 2 head gaskets. power is great, tons of torque. i run mine on straigh pump fuel.

[parts eeter]

This is exactly the info I am looking for.I think I will probably get the heavy duty studs and install them.Do you credit your head gasket problems to the studs pulling loose??I have definitely decided to go with the 11;1 wiseco piston however I will be using the .040 over 11:1 instead of the .120 over one I have already.Would you be interested in a good deal on my piston kit.Its new in box and I can provide the part numbers for you if you would like.$75.00 plus whatever shipping is.I will try that magnum cam when I first break my motor in and see how I like it,but I may end up just goin back to stock later.With the 11:1 kit and cam will I lose any low end at all??? If its same or better on low better on mid and on top I would be super cool with this combo.If I lose any low at all I will be BUMMIN,so let me know about that aspect and let me know if you need this kit or somebody that does.I dont need it.

[underpowered]

i do attribute my head gasket problems to the head studs but also the gaskets. i used fiber gasket that blew out, the one i have now is a cometic flexsteel gasket and is much harder to blow. i may be interested in your piston, i am tearing mine down tonight to see what it looks like and to install a new cam. ill get back to you tommorow on that.

as for your set up, with the cam and piston you may lose a little bottom end, but not much. sounds like a stage one cam is more suited for you. the stage two is a mid-top cam and you will gain a bunch on top and in the mid range and your bottom end will either stay about the same or may drop slightly.

[parts eeter]

Thanks for all of the info.I have decided to go with the .040 11:1 wiseco piston with the stock cam with the decompression assy removed.After break in and getting used to the extra compression and how it rides like that I will swap to my new cam and compare.I have found that in the past I have had best luck only changing one item at a time.Sometimes the new part stays and sometimes it gets removed.I will have to wait and see on that.Thanks for the info.I will give C&D a call Monday to get my gasket on the way.Let me know if you need that piston kit.It will save you a little dough and its the least I can do to thank you for all the info you provided.Thanks Colby,and Tyler:D

[underpowered]

wont be needing th episton kit for two reasons. tore the quad down last night and the piston is in near new condition after a year adn a half of riding so there is no need to replace it, but also i found that my bike was not a 426 with the stock sleeve like i was told. i had no need to measuer the bore before today since i am ordering new rings just because. it turns out, i have a 440 which in a way actually dissapoints me.

[parts eeter]

Yeah thats my reaction to thinking I had a 416 kit and I really have the 426 kit..I know how ya feel. When you refer to the hot cams are you referring to the magnum cam?? I dont know if people refer to the magnum cam as "hot cams" also.I wish I lived close to some of u guys so I could take a hot lap on the differnt engine combos and compare them against others.I am glad to hear your 440 performs well and is reliable also.I had a buddy that had the 12:5 400 and it was a really poor running machine.I didnt build it nor do I know who did but I will chalk that up to unknown components and possibly worn parts also.My other buddy has one that lost compression and quit on him and I am thinking we need to dissassemble it and check for a blown head gasket.Thanks for you help tyler.Now that I hear you like your 440 I am excited to rebuild a 440 and ride it and compare to my 416 or 426 I am building.I will be able to say I built 2 and be able to compare exact combos and jetting for reference.

[underpowered]

Hotcams is a brand of cam. just like your magnum cam. teh Magnum is actually a copy of the hot cam, a less expensive version. many companies make cams like Hot cams, Magnum, White Brothers, Web, TC, and other names as well. if you want the specs on each cam, check the FAQ forum and there a post with the specs on some popular cams. I dont believe it has magnum, but has many others like Hot cams that would be comparable.

[Colby@C&DRacing]

The magnum cam is a copy of the web 479 cam.

[underpowered]

here is a list of the specs
400EX CAMS
BRAND & MODEL IN.LIFT EX.LIFT IN@.050” EX@.050” NOTES
STOCK 400EX .316 .302 234 238 OEM
XR400 .326 .321 240 244 BIKE SR
WB ALL AROUND .345 .335 240 248 SR
HOT CAMS STAGE 1 .354 .354 244 244 SR
WEB CAMS 479 .378 .378 250 250 HR,VS,VG
HOT CAMS STAGE 2 .346 .346 254 254 SR
HRC .350 .339 254 256 HOP-UP
GT THUNDER* .350 .345 256 256 SR
WB TRACK* .350 .345 256 256 SR
WEB 450/451* .350 .345 256 256 HR
WEB CAMS463/9i .385 .370 272 270 HR,VS,VG
(In order from shortest duration to longest)
SR=Stock Rockers, Valve Springs & Guides OK
HR=Hard Faced Rockers Recommended
VS=Stiffer Valve Springs Required
VG=Shortened Valve Guides Required
*SAME GRIND

[parts eeter]

Hey guys if I ever post or have a question I hope you both reply,because the info u are providing is exactly what I needed to make informed decisions.I have decided on the .040 11:1 wiseco and stock cam with the decompressor removed.I am just a woods guy and like my trusty crusty powerband the way it is.The extra comp oughtta be just what the doctor ordered.It was almost there performance wise but just needed a little help in the motor department.The suspension was where all my $$$ had to go cuz the stock stuff went in the garbage.
Can I use the stock size metal gasket for the head with a plus .040???
Thanks guys Other than this my other questions I have will be in regards to axle recomendations,aftermarket levers,and some nerf bar info.I hope u can answer these questions when I have time to do more research.Again thank you both very much.If either of you want to get together and ride the Hatfield McCoy trailset in WV this spring u r much welcome to participate.Go to their website its a great place to ride.