What size?

[jal232]

Ok, Im getting rid of my YFZ, due to not riding much. So Im going to get a 400EX and do a total rebuild on it. Im deciding on what size bore to go with. 416,426,or 440. I know Ill wont be able to get the 450 type speed back, but I want something that is giong to pull hard on low end, and still have some speed. I just want some snappiness out of it. I have always owned Yamaha, and figured some of you Honda guys could point me in right direction. Also what kits from where are the best to run. Good reliability, and starting.

[michaelj]

I wouldnt get a 400ex if you want alot of low end power and snappyness, I would buy a used raptor off here from somebody instead, the 400ex is slow stock, although it is real durable and handles really well.

[greenblood01]

If you're not racing it or worried about the most possible horsepower, I would just do a 416 with a stage 1 cam (to get your low end) and a good full system exhaust. If you start with the 416 you'll have something to go to when its time for a rebuild, and I highly doubt you'll sacrifice that much power from 10cc, then again that all depends on what compression you go with.

[drew416ex]

Originally posted by michaelj
I wouldnt get a 400ex if you want alot of low end power and snappyness, I would buy a used raptor off here from somebody instead, the 400ex is slow stock, although it is real durable and handles really well.

If you are talking about a 660 then I would love to see a stock one that will do anything. Back when I just had a pipe on mine I could beat one.

[TRXRacer1]

Originally posted by greenblood01
If you're not racing it or worried about the most possible horsepower, I would just do a 416 with a stage 1 cam (to get your low end) and a good full system exhaust. If you start with the 416 you'll have something to go to when its time for a rebuild, and I highly doubt you'll sacrifice that much power from 10cc, then again that all depends on what compression you go with. X2 except I wouldn't bother with a full system, the stock head pipe makes really good low end already. You just need to clean up the welds.

[greenblood01]

I'm not a 660 fan. I work at a Yamaha-Honda dealership, and they are one of the last sport quads I would buy. Some people will disgaree, but I would rather have my old Kawasaki Mojave than a 660R.

1. Reverse is on the back of 2nd gear and is WAY too high
2. Early models had big time 2nd gear issues
3. All they want to do is wheelie, and are way too top heavy
4. Many of them have starter clutch problems
5. The dual carb setup is a joke, and a pain to tune or work on

[greenblood01]

Originally posted by TRXRacer1
X2 except I wouldn't bother with a full system, the stock head pipe makes really good low end already. You just need to clean up the welds.

I agree, a slip on would do anything a trail rider ever dreamed up. The stock header seems to work fine, especially for low end purposes. Mine already had a powerbomb on it when I bought it, so I couldn't complain lol.

[trx400EXtreme]

yea just go 416 11:1. from what i hear, (unless you go 440), theres really not much of a difference between a 416 and a 426.... it;s the compression that gives you the biggest gains. don't quote me on that that is just what i have been told.

[thisperishedmin]

I have to question your motives for wanting the 400...is it just to do a build? what drives you away from the 450?

Ive got a pretty heavily built 416ex, and while its a great ride and runs toe to toe with my friends and brothers mostly stock yfz 450's...there isnt a second I woudlnt rather have one of those lol.

If youre really sure about it - id also go with the 416...gives you more room to play with later and will wind up real nice with the right stuff done.

[jal232]

Well heres the deal. I have about 12K invested in my 450 now. I want to sell it and set out to spend around 5K on something else that can be a good casual trail/MX ride. I just cant go without having one to ride when the time comes, so there is no point in my 450 just sitting in garage brand new.
So I have always wanted to do a TOTAL build, so I think the 400EX is a pretty good model to get an all around quad out of. I will powder everything, extended a-arms, aft mkt shocks, tires, plastic, etc. etc. all the good stuff.
I know that it wont be everything my 450 is, but it will be a good weekend get away with friends from time to time, plus I enjoy the hobby-sport, and like maintaining them. Im a maintenance freak!

The 416 does not have cooling issues correct?
The 11:1 compression does not have starting issues, and can run off pump gas still?

[jal232]

Also, what web sites, or product lines are the best to purchase kits from? In fact I would much rather send the top end away and have it built, no anyone? Or websites, so I can start pricing away

[drew416ex]

No over heating problems with a 416 and you can run pump gas on 11:1. Check out thumper racing, they did great on my stuff. I think C&D racing has some pretty good prices too from what i have heard.