440??

[spdygonzalez450]

Hey what is up? i was wondering if i did the trinity 440 kit to my 400 and put a new carb on it will it be able to keep up with a yfz450 with a pipe and the cam mod? if not what could i do to be able to beat that quad? it is a 2003 400ex. Also does anyone have the trinity racing 440kit? if so do you know the numbers it puts out and how do u like it? thanks

[exatak199]

get the Sparks 440!:D

[cals400ex]

i don't think you will have a prayer. i have been told that those yfz's fly. i talked to a guy with a 440, high compression piston, race gas, cam, rockers, carb, pipe, jetting, etc and he said he was beat by a yfz. i am thinking this yfz he raced was stock too but it may have had a pipe on it. he said his 440 had more torque but once he hit the upper gears the yfz started pulling. good luck though.

[Nausty]

yeah about is all you can do to the yfz is exhaust, filter and couple other things that won't make a lot of differance.


If you already have a nice 400ex it would pry be better just to mod it out to where its close to a yfz. I dunno if it would beat it though but i'm getting a full sparks 440.:D

[spdygonzalez450]

yea i hope that i can maybe do the 440kit, i dont know what one i will do or maybe the 450r is soon to come. what are some of the numbers of the sparks kit? i have also heard that the 440s dont like to be reved? is that true?

[kenny]

i rev my 440 all weekend long it runs fine.poss you can change your gearing to keep up with a yfz.if not maybe just put a slower rider on it and tear him up. :)

[spdygonzalez450]

kenny, does your quad keep up with the yfz? what kit do you have and do you like it? also what type of gearing would you think would be best?i want to beat my friend. so any suggestions will help.

[duneittilludie]

spdygonzalez450-My wife has a very fast 440 ex that will usually hang with most of the fast four strokes but it is asking a lot of a 440 to compete with a piped and modded(CAM -AIR FILTER 450).From what we have seen and we see quite a few 450s where we ride you would have to build a 440 much further than i have ever seen one taken.A properly set up yfz is so fast off the line that it is very tough to gain back the lead they get initially.We have seen a 450 that is on nitrous and alcohol and it takes anything that it comes up against it although i am sure some of the fastest two strokes would give it a race .I guess what i am trying to say is i am sure you could build a 440 to consistently beat a piped 450 but it would take some serious cash and a lot of maintenance to keep it running.

[spdygonzalez450]

duneittilludie thanks for the info. what kit does your wife have? Also i have a 250r 3 wheeler motor? do u think that it might be a better idea to maybe put that motor in the 400 or to do the 440kit. the 250r motor runs good i ride it everyonce a while. any imput will help. thanks

[duneittilludie]

spdygonzalez450- My wifes 440 is actually a pretty mild build(11:1 piston-midrange cam-k&n-power bomb header-fmf q-pipe and no air box lid). As you can see we are still running the stock carb and will probably continue to do so because the stock carb when jetted properly can run very close to a fcr or similar carb.One of my friends that rides with us had his 440 built very similar to my wifes by the same mechanic that built hers except that he runs a 39mm fcr and 12:1 compression and she can still just barely beat him.If you take the time to get your jetting spot on and use the proper fuel along with the correct gearing for the situation you can do a lot with a mild build like we have.I mention the jetting specifically because it can be one of the most important changes to enhance performance that you can do and if done wrong can hold back your power quite a bit.The 11:1 seems to be a good compromise for the compression level on a 440 because you dont have to run too much (race fuel) to keep it running correctly.I have found that paying attention to a lot of the little things such as tire choice,gearing,suspension,fuel,and even chain tension play a much bigger role when added together than most would think so i would keep that in mind also.