If I were to do a 440 kit on my EX, I'd want to hear first hand what others have done (as Honda would fieldtest before making a product)to make sure this is the right decision for me. I'd hate to make a poor decision on my $6000.00 investment...wouldn't you? I'm looking for info such as mechanic or self, Honda shop or other, ratio's, cam's, kit or piecemill, preferably pump gas, and above all else...reliability. Looking back, would you have done something different?

 

It Rocks. Nothing like a 400. Went 1 up on front sprocket, 1 Down on rear, hits rev limiter in all gears so far but 5th,(ran out of space). Retained stock rev box for reliability, not too bad on gas vs. stock(you will be revving it harder to have fun, naturally, so you are using more gas)Not an uncontrollable power, still fairly smooth, and the kit isnt too bad, did it in my garage with my brother(he has building experiance). Went White Bros race cam, because i was told that the Woods cam would be too much torque. I believe the guy. After race cam and stock gearing, was tough keeping front end down. Email me with any questions, ill send pics. I think it cost me about 5-600 dollars by the time i was done.

 

You tell 'em Thumbthrottler.I haven't had any reliability probs.It does kick a-s!!I haven't come across much that can run with me.Around my area anyhow.Good luck with whatever you do..

 

is there really a difference between say and IMS440 kit and a THUNDERGT440 kit? Also, what are your guys dynos with the kits? How about costs including labor? THanks.

 

It is great that all you guys are happy, but I think what Extreme was asking and I am very intrested also is some hard facts ie: radar comparisons, dyno testing for hp gains and where? Are you running pump gas and how long have you had your kit? Any problems?

I hear alot of you guys say it rocks and beats eveything around. How about against a stock 400 and how many bike lengths. What other machines so we can have a idea of the increased CC's.

 

I ride and prefer a 425 over the 440. I have ridden several 440 equipped bikes and have yet to ride one that I like the power on better than my 425. I don't ride MX so I can't speak to the benefits there, but in the woods, the smoothness and snappy throttle response are more important than 1 or 2 HP. As far as fuel, I'm not sure how people are running pump gas in a 440. All of the 440's I know of run at 11.5:1 or higher and pump gas will not run well in a high compression motor. And even if it does, there would have to be detonation which will eventually waste the piston. So, if your going to spend the money on a big bore kit, expect to pay the price for race gas as well. To date the White Bros. cam has been the most popular, however, I'm investigating other possibilities for my yearly winter rebuild. If I find out anything newsworthy, I'll let you know.

Good Luck!

 

I have a full race 440 w/13:1 compression, big valve kit, full race cam, 39mm FCR carb, and LRD exhaust. LRD did extensive port work to the head and intake. The kit I have dynos @ 46 h.p. I have had my 440 since April 2000 and have had no problems. I also have several races on the motor. The only thing I would look into if I were to do it again would be A carb with a choke on it. When the temp. is below 40 degrees and I am above 2000' it has trouble starting. I actually have to be towed to get it to start sometimes. Also make sure you hard face the rocker arms when replacing the cam. You'll regret it if you don't.

 

How much was your kit? where did you get it done?

 

http://www.geocities.com/~gtthunder/testbed_set.html

 

Since I just got mine back on Monday, I haven't done anything other than fire it up and ride it down the street. In third I had a hard time keeping the front end down and per the name I'm not a small guy. However, I was told by the guy that has run a machine shop and races quads to avoid the 440 kits, unless that is truely what you want. It's all based on preference, but his suggestion was to bore the head .80 over and increase your compression ratio. That way if anything happens with your motor, you have room to bore it more and put a sleeve in. With the big bore your at the limits. For me this was the best solution, since my FMF core IV provides all the bottom end I need, I was looking for top end. So I had it bored .80 over and put an 11:1 compression piston. In addition I had the heads ported and polished and a race cam added. The whole thing ran about $800. The true test will be this weekend. I have two freinds who pick up Raptors today (They've been riding 250r's forever)so I won't hold it against them. But we are going to run comparisons between the Raptor, Raptor (piped), 400ex Piped, and my 400ex with the previously outlined work. Our riding skills are pretty similar and we are comparable in weight so it should be a fair test. However, he may be a little better skilled, but I'll never tell him that. Bottom line, I did what your doing and it makes sense. If you read the forums going back there are alot of opinions, just remember they are opinions. Good luck in your decision, but I would suggest paying someone to do the work unless you have the skills and not the money. It's worth having a professional.