416 build questions

[0101]

I'm planning on building a 416 in he near future, and have a few questions.
Build specs:
87mm 11:1 wiseco piston
Stage 2 hotcam
Mild port and polish (if I have time)
Maybe grind/lap the valves

Can I leave the engine in the atv and take off the top end and jug, leaving the bottom end in?

Can I keep the stock carb? Or is it worth it to get a 450r carb?

I should be able to run pump gas, correct?

Where can I find a shop manual for the 400 online to download?

Thanks,
0101

[brae5]

If you want to run pump gas it'll be fine just run premium..motor can stay in frame...while your in there put a cr450 cam chain in there

[whc]

I have a 416 wisco piston 11 to 1, with a stage one hot cam, open air box, modidied stock eshaust, I think my current jetting is 168 main, If I run 93 octane fuel it will ping quite a bit on hot days. I run 110 and 93 mixed 1 to 2 this seems to help. If I lug the motor it will still ping on hot days. its possible with the stage 2 cam you will have a bit less comp. then with the stage one. and that may make a difference. there are a lot of vary opinions on this subject will be interesting to read all the replys. bill

[CJM]

Should have no problems, I have pretty much the same setup and I run on pump gas with a 170 main, 42 pilot and 2.75 turns out the a/f screw. It never pings or gives me issues. I am not sure why others ping other than the bike is to lean.

You can leave the engine in as others have said.

Google for the 400ex manual

Stock carb will be fine, 450r carb is a nice add on tho.

[0101]

Thanks for the replies.

I will be keeping the stock carb for the time being. Where should I start with the jetting?

Is the port and polish worth it? Is it possible to port it too much?

What special tools and such will I need? Ring compressor? Valve spring compressor? A press for the piston pin (or will it slide right out)?

Will I need to shim the cam or anything?

Is the xr400 chain worth it? I know it's good insurance, but has anybody actually broken/stretched their chain, or had their timing chain skip gears before?

-Kevin

[0101]

In addition to my above post, can I just buy a xr400 top end gasket kit? Or do I need to buy a 400ex top end gasket kit, along with a xr400 head gasket? The xr400 gasket would be for the higher compression from the thinner gasket.

-Kevin

[vinson581]

i would just go with the cometic gasket kit, you dont really want to bump compression anymore as you already right on the border of pump gas with that piston (although 93 is fine to run)

[0101]

As asked above, will I need to shim the hotcam?

Also where should I start out for my jetting? Ill be riding anywhere from sea level to 7000 ft.

[CJM]

Dont need to shim this type of cam, just adjust the valves themselves and its super easy on this quad.

Jetting is relative to elevation, sea level to 7000ft will be dramatic changes. Jet it for where you ride, higher up in elevation you go the the more you drop the main jet. Figure a 2 sizes every thousand feet.

[dariusld]

I did my own port and polish and just didn't go crazy. I'm sure an engine builder would get more HP but they are not free. I just used my cordless with some special bits. I couldn't get to deep this way though. I did what I could and was happy with outcome.

[0101]

Originally posted by vinson581
i would just go with the cometic gasket kit, you dont really want to bump compression anymore as you already right on the border of pump gas with that piston (although 93 is fine to run)

Is the cometic kit stock size? Or is it a paper/thin gasket?
Can I use the stock size for the 416 bore?

[CJM]

Yes you can use stock bore size with a 416. Its very important you buy the cometic multi-layered steel gasket and not the paper one. The multi-layered steel gasket will look almost rubbery in pictures

[0101]

is this the one?
http://cgi.ebay.com/ebaymotors/HONDA-TRX400EX-400EX-COMETIC-TOP-END-GASKET-KIT-99-08-_W0QQcmdZViewItemQQhashZitem35b236a6f9QQitemZ23062 3192825QQptZMotorsQ5fATVQ5fPartsQ5fAccessories#ht_ 2404wt_1128

[CJM]

Yes. But be careful buying the stuff on ebay. Buy it direct from cometic if you can and buy the one marked "MLS" aka multi layered steel. Call them if you have to.

Reason being is I just bout gaskets from Jeff at apex and he sent me the wrong ones and explained to me that he never changed the picture. I was annoyed at first, but he is making good on it for me and Im quite happy. Ive bought stuff from them before and never had issues. not trying to plug apex-just gotta say i was happy the way he handled it-he personally called me back on my cell today! Cant get that outta most people on ebay these days!

[honda400ex2003]

on a side note... glad to hear you got that taken care of marc.

cometic is the only way to go imo.
steve

[0101]

It looks like all of them on cometics site say MLS... am I missing something?

They all say MLS/C.O.T. .027" next to them.

Maybe the C.O.T. is their paper thin one?

[CJM]

No idea what COT is, just make sure the gaskets are not paper but a metal rubbery coated type. They call them MLS viton coated iirc.

The best kit imho (but its $$$) is cometics topend EST kit. it comes with all O-rings, valve seals, and the gaskets. But its 80 bucks.

@Steve: Yea Im happy it worked out. I honestly couldnt wait and ordered some I hope the right ones from someone else too. Not a big deal since I can send them back I spose. What I liked about Jeff @ apex was although I gotta pay the difference since its his mistake hes gonna eat the shipping on the wrong ones and he got a me a deal on the EST kit for his dealer price (half the cost!). That and like I said how many ppl will actually call you and try and make good-I spent a good 15 mins talking to the guy-super nice!

[jasonwayne222]

ive got 416 wiseco 11:1 stage 2 hot cam and +4 timing advance key and i just jetted the carb and run a mix of supreme and avgas which is 100 octane, it goes for around 4 a gallon and i never ping or anything, the only downside is that it kinda stinks