Yfm350 serious power build!!

[beastlywarrior228]

The 446 and 460 will be fine with it just watch you shift points

 

[rappy'97]

No more 9,000 rpm lol
I just cracked it open, I have a bent valve. I guess thats what 9,000rpm does to motors...

 

[beastlywarrior228]

No probably 7000 is max, 6500 for best reliability. Which quad did you do it to

 

[beastlywarrior228]

Oo not to forget about a lightened flywheel for a serious power build

 

[rappy'97]

No probably 7000 is max, 6500 for best reliability. Which quad did you do it to

How and the world am I going to be able to run N2o then?

 

['00 WO-YA!]

Well boys, I just have to post this. It's not Warrior but is Yamaha & I did the work so I wanted to share. My cousin has a Blaster, it has run pretty good but I talked him into pulling it apart & letting me try some of my skills on his jug & a milled head that he had. I've done some reading on port timing on the lil 200 engine & just looking at the ports & reed plenum I could just visualize improvements. Starting top down the head was milled flat to the base cooling fin so I studied some redesigned Blaster heads & I radiused the chamber, opened up around the spark plug & polished the chamber nicely. For the jug, I raised the exhaust port, chamfered the jug entering the exhaust port, enlarged it & gave it a nice D shape & polished it. I cleaned the transfer ports & removed the slag & casting mess & blended as far as I could. The reed plenum/chamber was where I spent a good 2.5hrs alone. I'm picky! The ports were cleaned, the dam inside the plenum was reshaped, the ports were raised & the area was textured properly. I also carefully blended the port shape to the piston's transfer ports. Wow boys!! Wow! I couldn't believe the improvement on this quad man! I LOVED IT! I am still so amped b/c it's my work ya know. The engine has a 68mm bore, Boyeson reeds, Toomey B1 Header & silencer with a Uni filter & 310 main jet. It was carrying the wheels in 4th & 5th tonight with my 225lb ass on it! I'M SO PLEASED! Gonna have to take 2 Ambiens to get to sleep tonight, lol! I feel like a kid again, I had a Blasty when I was a teen & man I wish I had it back now! Hope you guys enjoyed, sorry for the run-on, lol!

 

[rappy'97]

Nice. That's awesome. Ihave my motor all apart right now aswell.......

 

[jasonp]

So, the cases are the problem?

Yeah you can only bore the case halfs so big to clear the bigger sleeve. . then there is very little material left for the head studs, which will pull out.

FST used to make a 490cc kit for the warrior but really what is the point. It's really not going to be any faster then a stock 450cc racer.

Just so you know, not to break any of your hearts here but the warrior engine will never be a "racer" rev happy, make power at 9000 rpm. It really doesn't have the head to do it. The motor is just a low tech, heavy beast that is built like a tank. I'm not trying to be negitive here but just to show you that I've actually tried...

My head was done at duncan racing, all out port job and bigger valve.. etc. I have the Mega .450 cam and 36mm flat slide carb. JE piston that has 225 psi of cranking compression, .040" of deck (which by the way this cam, exhaust valve bearly clears the piston and is under spec). Adjustable cam sprocket, Dynatek CDI box, open race exhaust, lighten flywheel ... etc. This is a fully built pump gas engine. It will not rev past 8000 rpm and make power up there. Really right around 7500 rpm is where I hit my max power. I have played with cam timing, different cams, bigger carbs... etc. It doesn't matter because this motor was not made to make this kind of power up there.

I can and have reved this engine past 9500 rpm which only thing it does is ruin stators and wear out the crank bearing. It just is pointless to run this engine that hard.

On top of all of this. If I were to spend my money building this motor again I would have done it by installing a yfz450 engine or something like that.

My finding and thoughts.

 

['00 WO-YA!]

Thanks man, what kind of powedr did you make with your setup man? What exactly do you really believe this engine is capable of & what's the recipe for it? Also, honestly, I have a spare frame & I've been thinking engine swap myself. Do you have any plans for putting a 450 or 700 on one of these? I love the classicness of the Warrior, just disappointed in it's power & skeptical if I'll get enough juice out of it to make me happy.......also why I started the YZ250 engine swap thread. Thanks.

 

[jasonp]

Thanks man, what kind of powedr did you make with your setup man? What exactly do you really believe this engine is capable of & what's the recipe for it? Also, honestly, I have a spare frame & I've been thinking engine swap myself. Do you have any plans for putting a 450 or 700 on one of these? I love the classicness of the Warrior, just disappointed in it's power & skeptical if I'll get enough juice out of it to make me happy.......also why I started the YZ250 engine swap thread. Thanks.

I would invest my money into another type of four wheeler say like a 700r raptor or 450r. Basically for how cheap they can be had for it would be easier to start with that then try and build a warrior to be fast, in my opinion.

 

['00 WO-YA!]

I respect that opinion Jason, this quad has to hold me over till the wife & Ican get some bills paid down. However, I would like to see what it will run like with a fresh topend & web .430 cam. I'd like to replace the valves with a ligter+1 valve (I/E). Can I get 30hp with that. A 700r or 450 are in my wishlist, prolly gonna do the 700r tho b/c I think it suits me better.

 

[kyler]

if you still need a cam i got a megacycle 450 lift for sale... you can txt me at 812-545-6157 i dont get on here much anymore

 

['00 WO-YA!]

if you still need a cam i got a megacycle 450 lift for sale... you can txt me at 812-545-6157 i dont get on here much anymore

Thanks Kyler, I might do that, you'll prolly here from me tomorrow, I'll have a 540 area code. I wonder how the .450 with a 12.1 would do?

 

[beastlywarrior228]

Your static compression should be low enough to be able to run 93 with that combo

 

['00 WO-YA!]

We'll see if the price is right man that cam makes me wanna get the valves replaced with +1's.

 

[DeadLastRacing]

you can only +1 the intake valve. Just an FYI.

 

[duneracerweston]

not really if you can get a oversized valve for the exhaust with the same spec and all you could in theory oversize it too id love to do it if i could find one and have a +1exh valve

 

[DeadLastRacing]

I'm under the understanding that with a +1intake, there isn't enough room to get a +1 exhaust and still have them seated right. Also, they technically only sell a +1 exhaust valve for our jugs.

Plus, doesn't the smaller exhaust give yah more benefits. More of a regulated forceful combustion. (?)

 

['00 WO-YA!]

A smaller valve is moreefficient providing the port flow is sufficient. A) valve is smaller & lighter, less valvetrain weight, better valvetrain stability. B) A smaller valve in most cases will be less shrouded than a larger valve. All of this comes down to cylinder head dynamics that are pretty out there.

 

[duneracerweston]

I think that a order sized valve would be better then OEM