Boreing 400 etc

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Rockgrenade

Rockgrenade

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So how does this work? Do you get more speed when you do this? Does it give you more horsepower for say towing or pulling? What's the highest you can bore a warrior?
 
on a stock jug you can go to 85mm or a 366cc warrior but if a fst kit is done which involves a stoker crank new sleve and head work you could take it out to a 446cc wardog and I believe there was a 460 kit too
 
Oh ok, so you'd be able to tow / pull more with these kits? Pretty much making a sport quad into like a grizzly 450?
 
Yeah more power for sure, which means you'll be going through the gears faster. But to get more top speed you need to change your gearing. There are several stroker kits available from FST, Powroll, and CWR. CWR also offers a 400cc kit, which involves, boring out the cases (same with stroker), and resleeving the cylinder. CWR also offers a 410 kit that rebuilds the 400 kit when the time comes. That kit uses an 89mm piston if I remember, the 410 is a 90mm.


You could always do the hotrods 379 and use a more mid-topend cam to get a good overall power band. Only prob with the hotrods is it uses a cast piston that is only the factory 9.2:1 comp ratio.
 
Yeah I if I was goin to do a rebuild or even do a stroker I would deffinatley do a HC piston or otherwise in my mind its just not worth it lol
 
I got a forged 10.5:1 piston for it from jasonp. Only other thing you could do is eliminate the base gasket and run a thinner head gasket. That would get it over 10:1, which isn't too shabby. Decking the head .010-.015 that'll get it closer to 11:1. Only thing you have to worry about then piston to valve clearance. Depending on the cam you use ofcourse.
 
I don't see the big deal with strokers? IMO if you really wanna turn your quad into a strait line, balls out killer!! Yank the 2 valve engine, and drop something meaner in it..

You have to think about the money invested into your 350 to get the most power? The more you do to it to make more power, the less reliable the engine is going to be!!

Then you look at something like the 450 bike engines, or even bigger air cooled 2 strokes.. They have been swapped into these quads before, and you could do a swap way cheaper than building a stroker.. (2 strokes are dirt cheap to build)

I hope you know where I'm going with this.. But I say if you wanna get the most bang for your buck on a 2 valve 350, just do the basic stuff.
Go to 366. Hi comp 12:1 piston (Screw this 10:1 BS).. A good cam. A good CDI, and a good exhaust.. Then Flip the Bucks for a decent 38mm carb..
That would be a good little motor, that wouldn't cost you to much. The crappy thing would be the price of high octane fuel.
 
88WarriorBoy said:
Yeah I wanted alot of power a 450 swap or a 660/700 swap would be the way to go imo
Click to expand...

If it was me, I would try to stick with an air cooled motor..

I had originally looked at the old 550 maxim engines, or even the 600 seca's. (Both are chain driven).. If you want stump pull'n torque, those are the motors for you!!

They'll fit the frame. But you would have to ditch the stock fuel tank, and fab one to fit under the seat. You would also have to use an electric fuel pump..
 
I'm not a 2 stroke person, that's not to say I wouldn't own one, just not wanting to do a swap. I also have my original engine that I've been wanting to build so I can use it, and keep my current engine as a spare. My extra engine has a work rod bearing. Don't see the sense in rebuilding the crank when I can get some more power out of a stroker. It's worked out with parts availablity. Jasonp had the piston at the right time, and '00 WO YA! gave me a good deal on the kiddlewhite springs, black daimond valves(+1 in), and 252x1 (.450 lift) cam.
 
Gen1Pat said:
I'm not a 2 stroke person, that's not to say I wouldn't own one, just not wanting to do a swap. I also have my original engine that I've been wanting to build so I can use it, and keep my current engine as a spare. My extra engine has a work rod bearing. Don't see the sense in rebuilding the crank when I can get some more power out of a stroker. It's worked out with parts availablity. Jasonp had the piston at the right time, and '00 WO YA! gave me a good deal on the kiddlewhite springs, black daimond valves(+1 in), and 252x1 (.450 lift) cam.
Click to expand...

I mentioned 2 strokes earlier.. But the 550 Maxim, and 600 Seca engines are air cooled 4 cylinder, 4 strokes..
 
Didn't know about the maxim and seca. Honestly I think if I were to own a smoker it'd be an 83 or 84 250r. The airfoolers were a good engine and they had lots of suspension travel.
 
I see the point of swapping in another engine, thought about it myself. Conversely, it's cool to see what is possible to get out of the old YFM engine. Greg at CWR claims about 44-45 out of his complete 460 kit. Pretty respectable in my opinion. Prolly as dependable as anything else if put together & maintained properly.
 
well finally got my motor back together i have the 4mm stroker crank and went and had a jug spacer made to 80 thousandths with no gaskets blue silicone and bought the 85mm je piston 12:1 comp with cometic head gasket and it runs nice
 
I've been wanting to do that man. 388 would be cool. More square bore/stroke over the 379. Not a fan of spacers, was wondering how close it would be to us the +4 crank with a kodiac 400 cylinder and an 85mm 12:1 JE. That is why I was wondering how much taller that piston is over stock.
 
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