im really considering the possibilty of stroking my 350 warrior. but i have some questions. how far can you stroke the engines while still using the stock cylinder head. I do undsterstand you will need head work done as well i plan on doing everything from the cam to my valves. i want to be able to run off pump gas too. so as long as i keep a mid range comp piston would that be a problem running only 93? i plan on doing a .40 over or .60 over bore with it as well and run a JE 10.5-1 and a web .430
stroker!
- Thread starter Jnucc
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Gen1Pat
Well-Known Member
You don't have to do any head work to make it a stroker. But, porting, cam and HD valve springs will help to make more power, regardless of displacement.
You have a few options for stroker kits. The cheapest is the Hotrods +4 crank. You need to "stoker" piston, which is junk, because with a stock or replacement piston, it will stick up past the top of the cylinder. The "stroker" piston is deck height corrected. And, by deck height corrected, I mean it does not stick up past the top of the cylinder. HOWEVER, it is a terrible piece for performance. It is a good ways BELOW the top of the cylinder, vastly reducing the power potential for the engine. It is supposed to produce the same compression ratio as a stock engine (9.2:1) so you are not really accomplishing anything.
Your other options to run the Hotrods crank is to use an 11:1 Wiseco or either of the two JE pistons. You will need to have a base spacer made to move the cylinder up higher so the piston does not stick up past it. There is one guy that has gone this route. If you do this you will need a longer timing chain. One from a Big Bear or Kodiac 400 will work. Or, you can use the Big Bear/Kodiac cylinder (it's a little taller) and have it milled down to get zero deck height.
Now, with all that said, I built a stroker using the Hotrods crank and pistoin, and I left out the base gasket and had a custom .010" thick head gasket made so I could get the compression ratio to a reasonable number. Don't do this!!!! You won't get the life expectancy out of the timing chain because there is so much slack in it without the gaskets, and I had issues with the head gasket leaking multiple times. Also, the crank did not last more then 25-30 hours. After going back to stock stroke with an 11:1 Wiseco, and still running the same ported head with Megacycle cam, it is a better performing engine. I did go down one tooth of the front sprocket because it did loose a hair of bottom end torque, but, the engine on a whole feels the same. So really, the Hotrods crank is not worth it. To top it off, you will need an adjustable cam sprocket to correct your valve timing, because without the gaskets, or with a spacer/BB cylinder, your valve timing will be altered. Need to correct that for performance sake, and so you don't shove a valve into the piston (extreme case). Not looking so cheap now, is it? lol
If a stroker is what you want, contact FST (Four Stroke Tech) or, if you can get ahold of them, Powroll racing. They both offer big bore/stroker kits that make 430cc. CWR (Cycle Works Racing) used to offer a big bore/stroker for the Warrior, but, no longer are able to make cranks for it. CWR does still offer the big bore kit, and it makes 400cc. In all honesty, you're better off saving the money on having your stock crank stroked, and just get the big bore kit. It will make better mid-range to top end power, something the Warrior needs. If your crank is shot then I would get it stroked as it is about the same amount of money to rebuild your crank as it sits.
Also, with any big bore/stroker, or just the big bore kit, the crank cases need to be bored out to fit the new cylinder sleeve in it. That means the entire bottom end has to come apart. The biggest question you have to ask is, is it worth it? That is a lot of Doh-ray-me to drop into any Warrior, and while the results will be seen/felt, it's performance level will still not be where the 400cc and up quads are at in stock to mildly modded form are. The 400ex is about the only quad you'd be able to take on competitively. A stock Z400, probably. But, anymore then that and it's going to leave you disappointed, in my opinion. If you trail ride almost exclusively then you will probably be pleased with it compared to newer, larger, quads. On a track, or any type of head to head competition, you'll probably wish you have spent that money on something else. You can have a dynamite engine with a higher compression piston, porting, cam, carb, exhaust, etc, that won't cost near as much, and will give you a smile. Running pump gas isn't a problem with 11:1-11.5:1 providing you have a cam with longer duration to reduce dynamic compression. Food for thought.
You have a few options for stroker kits. The cheapest is the Hotrods +4 crank. You need to "stoker" piston, which is junk, because with a stock or replacement piston, it will stick up past the top of the cylinder. The "stroker" piston is deck height corrected. And, by deck height corrected, I mean it does not stick up past the top of the cylinder. HOWEVER, it is a terrible piece for performance. It is a good ways BELOW the top of the cylinder, vastly reducing the power potential for the engine. It is supposed to produce the same compression ratio as a stock engine (9.2:1) so you are not really accomplishing anything.
Your other options to run the Hotrods crank is to use an 11:1 Wiseco or either of the two JE pistons. You will need to have a base spacer made to move the cylinder up higher so the piston does not stick up past it. There is one guy that has gone this route. If you do this you will need a longer timing chain. One from a Big Bear or Kodiac 400 will work. Or, you can use the Big Bear/Kodiac cylinder (it's a little taller) and have it milled down to get zero deck height.
Now, with all that said, I built a stroker using the Hotrods crank and pistoin, and I left out the base gasket and had a custom .010" thick head gasket made so I could get the compression ratio to a reasonable number. Don't do this!!!! You won't get the life expectancy out of the timing chain because there is so much slack in it without the gaskets, and I had issues with the head gasket leaking multiple times. Also, the crank did not last more then 25-30 hours. After going back to stock stroke with an 11:1 Wiseco, and still running the same ported head with Megacycle cam, it is a better performing engine. I did go down one tooth of the front sprocket because it did loose a hair of bottom end torque, but, the engine on a whole feels the same. So really, the Hotrods crank is not worth it. To top it off, you will need an adjustable cam sprocket to correct your valve timing, because without the gaskets, or with a spacer/BB cylinder, your valve timing will be altered. Need to correct that for performance sake, and so you don't shove a valve into the piston (extreme case). Not looking so cheap now, is it? lol
If a stroker is what you want, contact FST (Four Stroke Tech) or, if you can get ahold of them, Powroll racing. They both offer big bore/stroker kits that make 430cc. CWR (Cycle Works Racing) used to offer a big bore/stroker for the Warrior, but, no longer are able to make cranks for it. CWR does still offer the big bore kit, and it makes 400cc. In all honesty, you're better off saving the money on having your stock crank stroked, and just get the big bore kit. It will make better mid-range to top end power, something the Warrior needs. If your crank is shot then I would get it stroked as it is about the same amount of money to rebuild your crank as it sits.
Also, with any big bore/stroker, or just the big bore kit, the crank cases need to be bored out to fit the new cylinder sleeve in it. That means the entire bottom end has to come apart. The biggest question you have to ask is, is it worth it? That is a lot of Doh-ray-me to drop into any Warrior, and while the results will be seen/felt, it's performance level will still not be where the 400cc and up quads are at in stock to mildly modded form are. The 400ex is about the only quad you'd be able to take on competitively. A stock Z400, probably. But, anymore then that and it's going to leave you disappointed, in my opinion. If you trail ride almost exclusively then you will probably be pleased with it compared to newer, larger, quads. On a track, or any type of head to head competition, you'll probably wish you have spent that money on something else. You can have a dynamite engine with a higher compression piston, porting, cam, carb, exhaust, etc, that won't cost near as much, and will give you a smile. Running pump gas isn't a problem with 11:1-11.5:1 providing you have a cam with longer duration to reduce dynamic compression. Food for thought.
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