top-end rebuild questions?

[quad2xtreme]

I need to fix an oil burning problem that is occurring when revving the engine a little or when accelerating through all the gears.

1. Do I use standard Honda gaskets to put it back together if I go with a 416cc piston?

2. Will the 416cc piston work well with the stock cam or should it be changed in favor of a stage 1? Someone mentioned the stage one increases the tapping sound.

3. I am using a stock exhaust and don't want to change this. Love the sound level from a stock exhaust.

4. Do I take the piston with the cylinder to the machine shop to have it bored? Does the machine ship know what size to make the hole based on the piston size or do I need to tell them? If so, what size bore of a 416cc piston?

I am not looking to spend a too much money increasing the performance as we are looking to replace the quads early next year.

Thanks for the help,

Jon

[400exdave]

I think your probably going to need to get aftermarket gaskets. because you will have a bigger cylinder sleave and plus your engine case will be bored out for the 416 kit. Larger gaskets for that.

When I bored my old warrior engine to a 446cc like 2years ago, I brought them the engine case, with nothing in it (like bearings and gears) and the cylinder sleave and the new piston and they did it from there.

And with the cam situation, I personally would put in a stage 1 cam for that 416 kit.

[duke416ex]

1 You can use stanard gaskets with a 416, I like the cometic brand gaskets though.

2 It will do fine with stock cam, but better with an aftermarket one, and I hear stage 1 is loud on the valves.

3 Look at pulse charger, keeping stock exhaust will be your biggest limiting factor if you start buildiong the bike, but keep stock exhaust.

4 Take the piston and the cylinder. I like to do this so they can measure of the piston instead of just saying it __mm. Plus some pistons include a clearance sheet to help them on what bores, but a good shop should be able to do it from the piston.


If you are gonna replace the quad before long, then regear, get a rev box and an air filter, remove the air lid and rejet and don't go into the motor, jmo.

[quad2xtreme]

thanks for the info and advice.

A local shop (Dirt First Racing) in Baltimore is going to bore the cylinder for $50.

I am already running an EHS lid and installed a Dynojet kit. Need to keep the stock exhaust to remain in "stealth" mode. I sometimes ride on county property and power lines. Ihe low DBs really help to keep the residents from bothering to call the police. You really have to be obnoxious to warrant anyone coming after you. It is about 20-30 miles of trails. To bad we have some idiot riders who stay in one spot for too long drag racing with the loud exhausts and piss people off. People have been riding for 20 years but access is getting more and more restricted all the time.

I don't want to go crazy building these bikes because we are thinking about getting new quads right after Christmas or so. Need to be sure the kinks are worked out of the new models.

[enduro400rider]

one word of advice to you if you bought your bike off of someone and not brand new, dont buy a piston until you tear the motor down. i bought my 400 of a guy and just last week i went to put a 416 piston in it and it already had a 440 kit in it. the guy had no idea it had a 440 kit so i was not told. it basically turned into a nightmare cuz 440 is the biggest bore and i was burnin oil. as for your motor i would put a hot cam in it. you can look at some exuasts there are a few good quiet pipes out there, mabe check out the FMF Q series. with the cam and piston you are not getting all your power you potentially have when your running a stock pipe.

[TC426EX]

you can use stock honda gaskets on a 416 bore. I think its a mistake to install a 416 and then keep the stock exhaust however. At least invest a small sum on a slip on and let that thing breathe. Its always good to bring the actual piston youll be using to the machine shop since not all pistons are exactly the same and it gives them the opportunity to check the tolerances

[Dirtiredneck]

I am thinking of doing a 416 kit in the winter after my two more rqaces are done. I need the extra power to keep up with the 450's on the straight stretches, but I am fine in the woods. Have you talked to dirt first about doing your whole kit? I wonder how much they charge. C&D wants $715, for port and polish, Bore, Gaskets, Valves, and JE Piston. I am going to do it in the winter when I am off season with GNCC, I would also recommend the stage two Hotcam. I have it now, and I pull good on stock 400's. I am also limited to where to ride around here, I live in Odenton, and they have shut down all the riding around here, But they are still sneaking in Patuxent.......

[quad2xtreme]

I haven't but might call them tomorrow since I haven't even ordered the piston yet. I am so busy with a new job that it is hard to find time to even call. I will let you know. That sounds like a pretty good price from C&D though.

One of the three quads is on the DNR "list" when we got caught at Patapsco State Park. I am sick of trying to find a place to ride in Maryland. Planning to move to Durham, NC next spring if all goes according to plan. I bought 42 acres in Augusta WV so I could build a track. I will end up selling it.

What exhaust you running? I am sure that makes a big difference for you in addition to the Stage 2. I doubt I will change more than I need to at this point. I want to see how the new Raptor looks as well as the z450.

Actually I am hoping Honda puts electric start on the 450r even if it results in a 375lb quad. That is what the current 400ex weighs anyhow.

/Jon