400 something cc?

[flynhawaiian1]

Hey all,

I decided to start my own thread instead of bumping in on Dave's 446 thread.

Well I'm Rob, I live in Yuma.AZ and I have a 91 warrior. About a year or so ago I bought a Motor on Ebay that said that the motor was a 430cc from a 99 warrior. I put it in my bike and what a increase in power. It was very noticeable. A 38mm flat slide carb was with the motor and it had a very bad flat spot. I didn't jet it not thinking of the fact the motor came from Ohio and I'm in AZ. After the flat spot she would hall a$$. I was told by a person at a local shop not to use the mikuni. So, I bought a 40mm Edlebrock for a yfz450. I am going to try this out.

That's the history till now. I saw that Dave has a 446 and I wanted to know if I could bore mine out to get this. Well, JasonP and Dave gave feed back and that's why I started this thread. They asked some good questions about my set up and this is what I found.

The Head was ported and polished and O.S valves were installed with a Megacycle cam and vernier gear. The case and cylinder was opened up to receive the new big bore sleeve. This is where I don't know if I really got a 430 or not the receipt didn't say what size kit/bore/or anything. On the receipt it shows that a new Rod,bearings and pin were installed.
Prices for each were on the receipt and not part of the big bore kit price. It didn't say anything about a stroker crank. I would assume that the crank would come with the Rod already together with the kit. This has me guessing that I may not have a stroker. CWR offers a 400 kit that uses the stock crank and a big bore piston/sleeve. Of coarse the big deal with this is I want more power. ;D In order to do that I need to know what I have inside.

How hard is it to pull the head so I can measure the piston?

 

[4wheelin]

this is not that hard to do and it can be done with the motor left on the wheeler remove the front fenders and tank and upper motor mont and start digging into it from there i would suggest ya get a manual to walk ya thur it all should be able to do this in a matter of a few hours.

 

[dave76]

Well here's my personnel opinion based on the info you gave. Powroll makes the 430 kit, but they use their cam, which is a Web based .430 lift cam. CWR does make the 400 big bore kit and they do use Megacycle cams. Now based on what your saying how this engines seems a down on power is leaving me to beleive it's a 400 bigbore and coupled with that huge 40mm carb you got, the upper RPM 252X1 cam, the Warrior engine being a 2 valver, you are basically removing any low speed torque. This motor wants to rev, but it's only a 2 valver, thats why longer strokers make much more power because they aid in cylinder fill. I would try using a 36mm carb first, this will up the velocity and give a better vacuum signal to the main jet for better fuel metering, this may also explain your "flat spot" on the old carb. Hope this helps man. Dave

 

[missouritrailrider]

if the cwr 400 kit uses stock crank, why does it require a case bore?

 

[jasonp]

if the cwr 400 kit uses stock crank, why does it require a case bore?

As soon as you press in a bigger sleeve, in which case powroll, FST, and CWR all use a piston bigger then 85mm then you have to go bigger sleeve (even for CWR's 400cc). When you bore the cylinder out for the sleeve you also have to bore out the case to except the new bigger sleeve as you need a little clearance in-between the two.
Overbores standard for them are.
Powroll 86mm 430cc stroker
FST 87mm 446cc stroker
CWR 89mm 460cc stroker and big bore.
This is why if you have the money and you have to have the cases machined for the 400cc CWR overbore then why not go stroker. It just makes sense when you have it that far appart.

 

[jasonp]

My guess is you have the 430cc kit from powroll. They carry both Megacycle and Web camshafts. I would check to see what cam you have. There is a way you can measure cylinder volume but I just can't think of the tool of what is it called. I believe all you have to do is take the spark plug out and then turn the engine over. I try and see if I can find it or what its called.

 

[flynhawaiian1]

Thanks all for the responses.

I ran the bike with the Edlebrock and it halls booty..... But, when turning the bike off I heard a kind of knock sound inside the motor. I started it up and listen no noise other than the valves. Turned it off and no noise. I did this a couple of times and every other or so time it would knock. What do you think it could be? I was reading in Dave thread that he was told not to rev in the 8000 range. My 14 year has been riding it and may have been revving it high. It has been 6 years since the motor was built.

As for taking the head off the only thing I'm worried about is the timing chain and how to take it off.. I have the manual on disk I guess I should be looking at that

 

[madcow]

Mine sometimes makes a clunk when you turn it off, is that what you're talking about?

 

[jasonp]

Thanks all for the responses.

I ran the bike with the Edlebrock and it halls booty..... But, when turning the bike off I heard a kind of knock sound inside the motor. I started it up and listen no noise other than the valves. Turned it off and no noise. I did this a couple of times and every other or so time it would knock. What do you think it could be? I was reading in Dave thread that he was told not to rev in the 8000 range. My 14 year has been riding it and may have been revving it high. It has been 6 years since the motor was built.

As for taking the head off the only thing I'm worried about is the timing chain and how to take it off.. I have the manual on disk I guess I should be looking at that

I think what you are hearing is the starter one way bearing clutch sometimes will make a clunk noise when shutting off the engine. Sometimes the engine will spin backwards and cause the one way to lock up and you'll basically hear the gears meshing quickly together and loading up trying to spin backwards for a quick second.
8500 rpm is all I would go with it.
I wouldn't worry about taking the engine appart personally unless something is wrong with it.