265 power valve vs. 330 non-power valve

[Blown 331]

I'm working on getting my 85 ATC250R back together and I'm stuck between 2 motors. Which do you think will have more power? Be more fun? Cheaper?

1) Split my bottom end to clean the broken piston out of the crank case. Probably replace all bearings and seals. Buy a new 310 top end from ESR and a 38mm air stryker. Their econo 310 kit is $800 and the kit with more porting, billet head (instead of cast) and 2 domes (instead of 1) is $950.

2) Found a complete motor ( I don't have to split my old case) supposedly all gone through with a Baldwin trans and Hinson clutch. And a CT2000 PV cylinder with new piston, cylinder is not intalled on bottom end. Also comes with a 39mm air stryker for $1300.

Which way should I go? The complete motor seems to be a better deal but I really have to way to know what I'm getting unless I just trust the guy. So the 330 will cost more but I'll know what I have and I assume it will be a quicker motor. It's a 3-wheeler so I obviously won't race it but I want it to beat my 450R in a drag race.

All opinoins are welcome.

[#1speedbump]

The 310 will be the faster motor but the 265 will be easier to use and the power will be more linear. Unless the motor comes with the reciepts and was done by a shop that is reputable BE CAREFUL. You may just end up buying a grenade. Also if you split your cases replace your bearings while your in there.

Another thing to consider is a 330 powervalve motor. The cases will need to be machined but you will never want another motor. Go ESR, they are less expensive and from what I have seen the perform better IMO.

And why not drag the 3 wheeler. Its lighter than most other toys out there. That equals a killer Hp: weight ratio

[Blown 331]

I'll check into the 330 power valve. Case machining won't be too big of a deal since I'll have the cases split anyway. I plan on going with ESR if I buy anything new, I have the ATC-5 pipe and I love it. I have a feeling that is going to more than I want to spend though. I don't want to go much over $1000.


And I do plan on drag racing it. Damn right it will be quick, it weighs under 300 pounds. We have a state park near by that has a lot of sand dragging. I just need to figure out how to keep the front end down.

[Blown 331]

I just got off the phone with ESR. Looks like I may send them my bottom end. They are going to do all new bearings, seals, gaskets, recondition the crank with long rod and spacer plate, bore the cases for a 330 non-power valve and assemble the whole thing for $1600 or less! That includes a custom head with an agled spark plug to clear the ATC frame! :eek2: Sounds like a deal to me! I know where my next paycheck is going.

[#1speedbump]

good deal. As far as keeping the front down. Look for an extended swinger. I recommend davemooreracing.com. This guy has a couple of very fast ATC's.

[beak7707]

Yeah A 330 pv will be outta that price range. I think the cyclinder kit alone is almost 1,600. No matter what you go with I would defentally replace all bearings and seals, check tranny, and be sure the crank is up to snuff.

[the_hulkamaniac]

I don't know if ESR still has them, but a couple of years ago I rebuilt my bottom end. I bought new machined cases from ESR, they were pretty cheap and came with all bearings and seals. I say get the 330kit, if down the road you want somemore power look around for a good used pv big bore.

But your pushing a trike, 330cc will make it fly :devil: