i think i want a 310 for my 250r?

[QCquad83]

i want to put a bigger jug on my r, but i don't know what to get.....right now one of my uncles has a CT 310 and he really likes it.....but on the other hand my other uncle has a CT 370 and he has problems with it......i race motorcross and i don't want something like the 370 that needs to be ran wide open. i was wondering what people thought about CT, or other piston and cylinder kits for an R in motorcross......Another thing i want to keep it moderatly cheap....i am a poor college student that doesn't have a whole lot of money....thanks...

Ive seen alot of people at the track running the Esr 310 i believe.

[wilkin250r]

The 370 shouldn't need to be run wide open. It should have monster torque and great low-end. The 310 would need to be run wide open just to keep up with the 370.

The 370 is going to be much more expensive than the 310. The 310 doesn't require to you split the cases to machine them to accept the bigger bore. Be aware, a do-it-yourself KIT will sell for about the same, but the 370 will require you to split the cases, costing time and/or labor costs to have someone else do it. The 310 should just bolt right on.

[INFANTRY RACING]

i'd tend to stay away from ct racing.. seen a few of the motors that made me the wtf were they thinkin

[QCquad83]

yeah i am looking for something bolt on.......i was wondering what people thought of CT. i have a freind that said he hated them but other people like it.......but would i be better off with like a 265 or should i just go with the 310........i think CT 310 runs around $900....and a ESR is around $950

[markeg192]

I udes to have a CT 310 and loved it. It pulled from the bottom nice and smooth. Easy to ride , hook up and go power.

[INFANTRY RACING]

a guy a raced with was a sponsonered rider throught them.. well his new powervalve cylinder got trashed by them sticking to large of a piston in it. if they can't take care of a sponsored rider then they got problems.

[racerx573]

You can a 300cc resleeve kit for a stock jug from LRD, it's a lot cheaper than a bolt on jug.

[bone705]

lrd told me to go with the 300 resleeve kit it would cost lie $1200. ESRs bolt on kits are under a $1000. it seems like the best bang for the buck would be esr. but i imagine u cant beat the quality of lrd.

[wilkin250r]

I have heard only good things about ESR, except for one issue. You don't want the 330 bolt-on kit. Ordinarily, 310 is the biggest you can go without machining the cases to accept the bigger sleeve. With the 330, they cut off the bottom of the sleeve, so you could run into problems there.

[AndrewRRR]

Do you race MX in a class with a CC limit? If so keep in mind the usual 265cc limit will put you in an open class, so you might want ot just get it ported in that case.
Personally I don't like CT racing. The general consensus is their customer service stinks and they do a lot of really ho-hum port jobs unless you really specify what you want.
On the flip side I've heard lots of good things about ESR big bores, and I've dealt with their customer service on several issues and it's always a pleasure.
LRD does good work for MX and woods motors but are generally more expensive. Personally I didn't like the porting on my LRD 330 cylinder so I had it redone. I wouldn't recommend sleeving out to a 300 on a stock jug, you are effectively reducing the size of your transfers. Just go with a big bore casting.
310R duner has a ESR 310 motor, might wanna talk to him.

[XANDADA]

Can't say enough good things about ESR products/service:D
Save up and go with the nikasiled aluminum sleeve & powervalve version. If ya want open class go with the 310 otherwise stick with the 265 (which is what I have). It has plenty of get-up-n-go fun.

[310Rduner]

I would deffinately go with Esr over any other company. The 310 cylinder I have was on the bike when I purchased it, so I can't say what it feels like stock, but I know that I have the hardest damned time keeping my front end down at all. On the sand the motor has power to pull 5th gear wheelies under acceleration without clutching and on a stock 86 lenth swingarm. On dirt or pavement the 310 just freaking pulls so hard, and the front end comes up in 6th gear without hesitation. It doesn't seem like there is an abrupt hit at all.. the powerband just starts picking up from the bottom and yanks your arms out from 1st-6th gear:devil: My neighbor across the street with a modded 400 was scared to ride my bike when he saw me ripping down the street but I forced him onto it so I could hear how my new pipe sounded. He came back shaking his head with a huge smile on his face, and shaky hands haha :blah:

On hardpacked, and softpacked sand when I drag and drop the clutch in 2nd I have to sit as far forward as possible to try and keep the front end down, which is still hard to do; and I weigh about 220lbs:o

I'm basically an esr wh*re, and the only engine work I will ever put on is from esr because of my experience with them, and the ho hum experience I hear everyone have elsewhere. Darren at esr is a great guy, and they have awesome customer service. When I bought my 38 Tmx from them, it was about 3/4 of an inch too short (carb is not as wide, and cr250 angled boot is also not as long) and I needed reed spacers to make it fit. Instead of raping me on the cost, they sold me the 3 I need for only $10 each, when most places would have charged near $30 for just one!

[250rpilot]

i too have to put in a vote for ESR. i bought a 330pv kit from them, it showed up in less than 2 weeks! i didnt get it finished yet, but i cant wait to get it done!! i tore down my bottom end and sent my cases, crank, and balancer to them. 3 weeks from the day i sent them out (took a week and a day to get there) i got a call and they are on their way back here. i hope to have the stuff by next wednesday. i cant say enough about the customer service, they give 110% to make sure you know what you are buying, and jetting, and any other question you want to ask. service before, during, and after was by far the best customer service i have ever received from ANYWHERE for ANYTHING!!!!! the posrting looks real good, and while you may be able to squeeze a pony or two more out of these cylinders, the esr porting is supposed to be the best of the "big company" style porting. from what i am told, you would be hard pressed to find a better cylinder for the money!

on another note, i bought a bunch of billet items from them as well, and they are some real nice pieces!! i am not easily impressed, but they have definately made a believer out of me:D

[sandspanker]

:) I would go with the esr330 bolt on. very good engine lots of pwr.buddy of mine has a 330 runs very good.best bang for the buck.i would rec. replacing 2nd and 3rd gear in the tranny. and up grading to a billet clutch basket. i learned the hard way when my tranny was laying on the ground.:(

[airheadedduner]

Originally posted by AndrewRRR
I wouldn't recommend sleeving out to a 300 on a stock jug, you are effectively reducing the size of your transfers.
Yup, I had a CT 295 resleave kit and the piston at BDC covers a large area of the ports still. To do it right you would have to have the cylinder dramatically ported to get back proper transfer, exhuast, and intake duration and retain a good blowdown duration. The other option is to have the cylinder decked about a 1/4 inch:eek: :eek: :eek: and run a spacer. That could effect reliability in a bad way though. Leaving it how it is still gives you good power from low-mid but it falls flat off the power curve way, way early. Personally my impressions of CT aren't great. They are a pain to deal with. While I was okay with my cylinder my friends CT310R, which was supposed to be there premier full on 310 kit, sucked. It couldn't beat my buddies T-5 piped shee on a hill climb. I would go ESR. Best bang for the buck when it comes to R motors;)

[twisted threads]

Originally posted by wilkin250r
I have heard only good things about ESR, except for one issue. You don't want the 330 bolt-on kit. Ordinarily, 310 is the biggest you can go without machining the cases to accept the bigger sleeve. With the 330, they cut off the bottom of the sleeve, so you could run into problems there.

I had a ESR 330 bolt on cylinder and It ran AWSOME! No problems at all.... I WAS NOT easy on it either.

[wilkin250r]

Originally posted by twisted threads
I had a ESR 330 bolt on cylinder and It ran AWSOME! No problems at all.... I WAS NOT easy on it either.

To be quite honest, I don't have personal experience with the 330 bolt-on kit. This is just the word I have heard from several different sources. Just like the Durablue axle. I've never personally owned one, and I'm sure there are people that have never had any problems with them, but that doesn't mean I'm inclined to buy one.

[AndrewRRR]

I wouldn't want to run a big bore with no sleeve extending into the cases. It's really not that bad to notch the cases. You are going to want to split them to match the lower tranfer ports to the new jug's transfers anyway. Might as well do it right.

[beak7707]

Do you guys really think the resleeves are that bad? How did Ballance and yokley win all those races with the LRD resleeve if its not as good. I heard ballance say a few times there wasnt a better R motor out there that the 300 resleeve. He said he could lug it around the corners and rip out of them. I know he is one of the best riders and lrd was he sponser, but he sure made me a believer out of it. Also I've never heard a bad word about LRD and I was told there porting work is second to none. Yes ESR is great stuff for cheap, but i dont think LRD resleeve would be a bad choice.

[airheadedduner]

They make good low-mid power but just fall flat on there face for top end. What happens is everytime you bore a cylinder you lower the ports a little. When you go out that far you have lowered them a lot. What you have done is reduced transfer port(and all the other ports) duration to a very large degree. So, when your piston is moving down and squishing the crankcase charge into the cylinder that charge is pushing out the burnt exhaust gasses(if you look at the transfers they are angled twards the intake slightly). Its called the (some foreign guy's name) scavaging effect. If the transfer duration(period in which the transfer ports are open) is to low the scavaging charge cannont push all the exhaust gasses out the exhaust port at higher RPMs. The residual gasses dillute the fresh intake charge reducing power.

I tried running an FMF top end pipe on my bike but it just gave it a wierd power curve. It lost some low-mid, picked up some in the upper-mid, but had very little top end power still compared to other R's. Ballence and Yokley both are XC riders so the setup makes ideal power for their conditions.

[AndrewRRR]

Is Ballance's 300 a resleeved stock casting? I figured he would go with a larger Pro-X like LRD uses for their 330 jugs. I'm sure his setup is totally optimized if he uses a stock size casting. They would deck the cylinder to keep the ports at the right heights and give him Arlan's very best port work. Keep in mind also his motor is setup for bottom and midrange.
If you haven't heard anything bad about LRD give me a call sometime. lol. Thats who orginally did mine. I'll see if I can find the before and after pics somewhere. I have no doubt Arlan is a good motor builder (for XC and MX motors) but mine could be taken way further reliably, and ported with something other than a chainsaw, lol.

[beak7707]

Yes ballances motor is the stock cylinder, just resleeved. And i didnt mean there wasnt ever a bad port job from LRD, but i know they do great work. You can list any product on this site and somebody would have something bad to say about it. I also agree ESR is a great motor, but it is pretty much unknown to the racing world. I never saw a R in XC with an ESR motor, i really dont recall ever seeing a pro run ESR. The reason i think the LRD 300 resleeve is ok, is because i want low to mid. Even if i went with ESR i'd get low end port. Its just what the rider needs, I'm sure you duners love the top end of an ESR. But for XC or MX i dont see anything wrong with LRD.

[airheadedduner]

If you are running MX I am not saying the resleave is a bad choice.....but. You would not be 250 class legal so you would have to run open where you would probly be outgunned by all the 310+ R's.


I am shocked to hear of a bad port job from LRD. What was wrong with it??

[250rpilot]

Originally posted by beak7707
I never saw a R in XC with an ESR motor, i really dont recall ever seeing a pro run ESR.

you will soon!:devil: :eek2:

[AndrewRRR]

Originally posted by airheadedduner

I am shocked to hear of a bad port job from LRD. What was wrong with it??

Yeah if you want a low-midrange motor LRD is a good choice. ESR builds great dune motors but I have no idea if they can build XC and MX motors that will beat LRD, Sparks, Paul Turner, etc.
Well mine was supposedly a dune port, and it ran ok, but by no means great or up to the potential it could have had. You can really open up a Pro-X 330 jug. I had Ripp's Powersports take it further. We ended up lowering the floor, opening up the ports a lot, cleaning up and enlarging the transfers, taking the floor hump out of the exhaust, widening it and polishing it up. It looked like it was ported with a jackhammer before, nothing was smooth or straight (by smooth i mean contour, I know you are supposed to leave intakes textured). LRD does great XC and MX motors but for top end motors I wouldn't put them on a "who's who" list.
Most reputable builders can give you a really good job if you build a relationship with them and be really specific of what you want from the motor. If you hand them your cylinder and say "port it" you'll get the standard Joe Blow job. If you talk with them for a while, and work out what type of motor job you want, you can get a much better job. If someone refuses to take the time to do that, take your business elsewhere.
If you have class restrictions go with a PV 265. If not, get the biggest mo-fo you can afford.

[310Rduner]

Originally posted by beak7707
Yes ballances motor is the stock cylinder, just resleeved. And i didnt mean there wasnt ever a bad port job from LRD, but i know they do great work. You can list any product on this site and somebody would have something bad to say about it. I also agree ESR is a great motor, but it is pretty much unknown to the racing world. I never saw a R in XC with an ESR motor, i really dont recall ever seeing a pro run ESR. The reason i think the LRD 300 resleeve is ok, is because i want low to mid. Even if i went with ESR i'd get low end port. Its just what the rider needs, I'm sure you duners love the top end of an ESR. But for XC or MX i dont see anything wrong with LRD.

Soo.. Johnny Hale isn't pro Enough for you??:blah: