350x power

[snakes350x]

I'm sure this has been asked a million times but whats one more gonna hurt. I was thinking of tearing down the 350x engine this winter, well top end anyways, and was wondering what any of you thought of the powroll big bore kit and the stroke crank. I gotta do the clutch anyways so i was thinking of doing piston and rings just so i know they are fresh. I thought if i'm going through all the trouble to tear it apart, as 4 strokes aren't as easy as 2 strokes, I might as well try to get a little more power out of it. Has anyone had any experience with powroll's, or anyone else's big bore kit? Good experience, Bad experience? Is it worth it and should i go all the way, bore stroke and cam and carb, or can you get away with just part of it, maybe just a bore job. Any help from you 4 stroke gurus would be appreciated. thanks

[az350x]

In the past couple years, I've had a stock motor with a 38mm Mikuni on it, and I've currently got a Powroll 393 with the same model carb. I can tell you that just the carb on a stock motor makes a substantial difference in both power and fuel consumption :D .

I can't give you much info on the Powroll yet, because on the first oil change after I bought it, the oil was full of metal, and I still haven't gotten it back together. It was running fine at the time, and I did notice quite a bit more torque from it, but beyond that I can't help you much. Mine is the 10.5:1 piston, with a Web cam and hardened rockers.

After seeing the receipts for my motor (I bought it already built), I can tell you that if it were me, I would probably start with a big carb and see if the power increase were sufficient for my taste. I'm wary of my engine because it's OLD, and parts are getting harder to find, so I would think twice about modding it extensively- something that will definitely have an adverse effect on it's longevity. I'm hoping to get mine back together soon, and hoping that if I take care of it, it will hold up long-term.

Good luck with whatever you decide.

[snakes350x]

Thanks for the help. Maybe i will try a bigger carb first. Cheaper anyways and then if i do go for the bore kit i'll have the carb already. You said you have a 38 mikuni on it 1 bike. Did it fit right in. What about the throttle cable length?

[ttyr2]

All things considered, throttle response and low-end torque go down by installing a larger carb. Stay conservative and the engine will run a lot better, crisp throttle response. Now, if yer just sand dragging, bigger is better, to a point.

[az350x]

Originally posted by snakes350x
Thanks for the help. Maybe i will try a bigger carb first. Cheaper anyways and then if i do go for the bore kit i'll have the carb already. You said you have a 38 mikuni on it 1 bike. Did it fit right in. What about the throttle cable length?

My Powroll had a twist throttle when I got it, which I immediately dumped. This required ordering a custom-made cable from Motion Pro (to mix the carb end with a thumb throttle end), which cost about $40 shipped. I emailed them pics of my cable at the carb end, and at the throttle end, and they put it together- no big deal. They were very helpful on the phone and via email. The cable only took about a week to get. Since the Mikuni cable goes through the top instead of the side like the stock one, have them put a 90-degree bend at the carb end, so you won't have seat/tank clearance issues.

[Mr. Richard]

Originally posted by ttyr2
All things considered, throttle response and low-end torque go down by installing a larger carb. Stay conservative and the engine will run a lot better, crisp throttle response. Now, if yer just sand dragging, bigger is better, to a point.

i think if your just sand draggin , you have the wrong trike ,,, if you get a carb ,pipe ,and cam, that should make lotsa power,,

[ridinfun]

a nice port and polish with over sized valves and up your compression will allways produce more power k&n filter,bigger carb or rejet.really depends what kind of power you want gearing will also put power where you want it cheap

[350XXX]

gearing for a 350x is kind of hard to find, unless you mean sprockets.

[ridinfun]

yeah sprockets