Yfm350 serious power build!!

[Jebbysan]

Jebby, is that an 86mm bore & stock stroke?

I believe it is an 87.5mm.....

 

[elwood]

hell even an old yz490 motor would be killer. the warrior frame has plenty of room in it for a motor swap.

I've talked about that before and it is a plan of mine, I've tried several times to do some bartering to get the yz490 but they all fell through

 

[Jebbysan]

I believe it is an 87.5mm.....

Sorry...yes it is an 86mm bore.....
87mm yields 386cc

A 10.5 to 1 dome would yield closer to 11 to 1 with this bore size...considering swept volume.....

Jebby

 

[duneracerweston]

Ya really think I can get by 12:1 on pump gas man? I can buy VP110 at my local Yammy shop in a 5gal can for like 55 bucks & mix it with 93, it'd still be roughy 101 octane but the wife would be pissed about payin that much for fuel, lol! Any links for how to build the air ducts? Are they just moving air towards an oil cooler or toward the cooling fins on the head? I'd like to see how some of this is done with the fan & what not. great post Weston!

well i gess it would be possible but the motor would haveto be built to run cool like 180 degrees or so other wise it might pre detinate and then you can kiss your crank jug and probably both cases so be carefull what you build it can bite you in the ass if you dont know what your doing

heres thie pics i just took sorry about the lighting ist mid day and hot as blue blazes

i added a peace of alum to the right side duct to dirrect more air flow around the motor and its ratty looking i know but it works wonders

the fan is a universal atv watter proof fan wired direct to the battery with a rocker switch on the left side frame rail pritty simple really

 

[rappy'97]

Why 180 degrees? That is cool to a bigger motor, such as a YFZ450 or 700 Raptor? The fans dont even turn on until 210+

 

[duneracerweston]

180 is optimum engin temp and if you can make it maintain that on the bench then it shouldn't get over 220 in the feild the lowest mines been is 245 to the head temp outside was 106 so not bad but not good enough for me

 

['00 WO-YA!]

put a yz250 2stroke in a warrior. hell even an old yz490 motor would be killer. the warrior frame has plenty of room in it for a motor swap.

Lol, I mentioned the 490 to my Bro.-n-law a couple weeks back, he said the 490's were screamers but just lacked in reliability, he's a bigger fan of the water cooled YZ. believe me, this guy would take a bullet for a YZ man so he wasn't just knockin the 490, I think he was just being honest. On a side note, shame we don't have room for a 1200 Sportster engine!

 

[1998yamahawarrior]

Im really contemplating a yz swap in Read Headed Step Child, just need to find a killer deal on one. Of coarse Ive also considered a crotch rocket engine swap too:evilface:.

Ive got an email out for a yz426 that some ones parting out right now.

 

[beastlywarrior228]

theres a yz400 for sale by me for 800

 

[1998yamahawarrior]

theres a yz400 for sale by me for 800

The guy that has the 426 only wants 900 for the complete bike, so if its half or less for the motor and the stuff for it to run, thats less than I can do a big motor biuld for.

 

[beastlywarrior228]

youll have to use a different radiator though

 

[1998yamahawarrior]

If I can get it you bet I will be driving over to Bryanquads place and getting pics and measurements of everything and then of coarse a right up will happen. We'll see though.

 

[beastlywarrior228]

If I can get it you bet I will be driving over to Bryanquads place and getting pics and measurements of everything and then of coarse a right up will happen. We'll see though.

yes id look into this if i can find a roller warrior for a good penny

 

[1998yamahawarrior]

Thats the nice thing about having 2 warriors, I can do it to 1 and still have the other for hard trail riding!!

 

['00 WO-YA!]

K, so we've all got different tastes & preferences, 4x4's, Porsches, Vettes, Harleys, etc. I guess the one thing we all have in common is the one thing we quit talkin bout....Warriors. Anybody got anything to add to the build of a YFM350 engine?

 

[duneracerweston]

Ya a aftermaket air filter and box that's it

 

[yfmdeuce]

where is the best place to buy +1mm intake valves? Any one shave weight off of the fly wheel? How far can you go before it starts stalling super easy?

 

[duneracerweston]

Duncan racing dose the lightening of the flywheels jasonp has used the lighter flywheel and he liked it can't give specifics cuz I don't know them

For the valves I think if I was to do mine again id use cv4's vlave kit they are different angles on the flow they are titanium and coated like nikasill cylenders but its a different coating

 

[Jebbysan]

My Warrior just rode over the clutch.......therefore my vette is faster...
Just kidding....but either my 40yo ass gets on it....or my 350 is making power....you decide!:atv:

 

[headache]

I think that the 400 big bore using the 89mm piston and stock stroke would be a good revving motor. the bore/stroke would be similar to a z400, however you would definetly need some head porting and bigger intake valve and maybe have a cam ground to match everything. i think an adjustable cam sprocket could be a good thing to help fine tune the power curve and then a proper carb. maybe a z400 carburetor would work good i'm sure. maybe even an fcr from a 450r or something along those lines.