250R ported cylinder VS non-ported cylinder

[gravelord]

how much of a performance gain would you get on a 250R vs not having any porting? highly noticeable differnce? if so let me know

[Derrick Adams]

diff is better than adding an aftermarket pipe

[Pete]

its a big difference if you have it done correctly. Factored with a bump in compression its the best thing you could do in my opinion.

[Jason Hall]

Night & day difference. No comparison to any other mod when done right, add a bigger carb like a 36-38mm & your Rippin.

[Eric250R]

You probably think I should know this but I really don't.
I have heard the term port and polish before ,,, I know that polishing the intake + exhaust areas aids in flow and discharge but what is the port part ,,, making it bigger or what ?

john
Yep, just open up the ports for better flow and let it rip!!:twisted:

[gravelord]

i have a short rod 250r engine, stock porting and bore, im getting a long rod with a port job, think ill notice a differnce? i already have a 38mm air stryker carb

[Pete]

if the portjob is decent, yes you'll notice it.

[ChrisD]

You don't polish the intake ports, only the exhaust. The clear, opened up ports are left rough for better atomization of the fuel.

Why do you want a long rod motor? The difference is not noticable. I have a long and short rod motor and they perform very similar. The only reason I went to a long rod motor was to use the big bore cylinder.

You will feel a big differece in port jobs. I crappy job will hurt performance and a good one will make your bike rip.

Good luck.

[Jason Hall]

The biggest thing you need to remember Is to keep the origional shape of the port's. If you don't change the shape your power curve should stay real close to the same. You kinda have to understand which way the air Is moving In the port, then think of how you can make the air go through better/faster. When you start hoggin & raise & lower the port's that Is when you mess up.

[deathman53]

its my motor he is getting, it absoletly rips. I liked that motor better than my esr330. It doesn't compare to my 310pv. He has a 38 a/s he got from me also. I used a 38 a/s, v-force reeds, atc5 pipe and cr igntition on that motor. The power hits at bottom, strong on mid and stops at almost to top. I has a cut head with it too. I will put on a stock trx gasket, so he can use pump gas. I haven't ran this motor, since it got put on a 88 250r bottom end(fully rebuilt) and it got a new piston and bore. I got his motor right now. His motor has issues, sprocket bolt snapped and upon taking off the top end, the crank bearings are bad, also shift shaft was alittle worn. Now a full rebuild is defintetly gonna happen.
By the way, Jason, you are gonna get 2 cylinders of mine, 85 and 88 cylinder.

[Jason Hall]

Deathman53, I bet that 310pv Is a sweet one. It's hard to beat a good running honda cylinder for certain riding condition's though. I've had my 310 on a couple different bike's but I still love my 10 over honda cylinder. I can't explain why, It's just super smooth & run's so good. 87 octane gas with a stock head. I'll be waiting for the cylinder's, thanks man :Bounce