ESR big bore

[rjt500r]

Looking for some feed back on the ESR big bore kits. I have an 88 250r and i'm wanting to go big bore. The ESR site has a stage 3 370cc complete setup for less than 2 grand. My bike is sand only so i would probably go with the TRX9 port and pipe. Are these package setups a good deal or am i better off having a local builder build a motor for me. The difference would be about $500- $1000 to have one built using the ESR cylinder his porting and pipe. Also power valve or no power valve for sand only build? Thanks.

[rsss396]

I think the ESR porting is fine for duning. A good builder that has built the ESR/ProX cylinders can probably get more performance out of them but obviously at more cost.
If you are into racing competitively then a builder is the way to go, but for a fun duning bike with good power ESR will just fine IMO

[etccb]

Those esr trx9ported kits are killer for the dunes. That is a good kit and you may also contact them via email and or phone if you can catch him to talk about the 363 4 mil stroke option as well that would be a little cheaper being it uses an out of box 4 mil crank vs a esr stroking a crank 5 mil for you. He will help you get what you are looking for.
As far as the power valve I like them myself. The bigger cc you go the more you will get mixed feedback on if you need one or not but it really is about the cost and what you want. For duning I love it, why not have some bonus grunt low when you want it when playing around turning hills etc. I dont mind maintaining and cleaning it now and then. Those are great kits with the power valve or going non, whichever way you want to go. It will make you a great duner R.

[Bowtie316]

My trx 7 port 330 just came back from the dunes and I was really pleased.  Glad I didn't go with the trx9.

[aberegg05]

MADE IN USA! Eddie sells great stuff. I have his 330+4. Trx9 port. Rips!

[rjt500r]

I think the ESR porting is fine for duning. A good builder that has built the ESR/ProX cylinders can probably get more performance out of them but obviously at more cost.
If you are into racing competitively then a builder is the way to go, but for a fun duning bike with good power ESR will just fine IMO

Thanks good info. It's a dune only bike not a competitive racer. The disadvantage it has now, is that my other bikes are 500 two strokes and the small bore 250r does not compare. It runs great and is a lot of fun , i prefer a little more low end grunt.

[rjt500r]

Those esr trx9ported kits are killer for the dunes. That is a good kit and you may also contact them via email and or phone if you can catch him to talk about the 363 4 mil stroke option as well that would be a little cheaper being it uses an out of box 4 mil crank vs a esr stroking a crank 5 mil for you. He will help you get what you are looking for.
As far as the power valve I like them myself. The bigger cc you go the more you will get mixed feedback on if you need one or not but it really is about the cost and what you want. For duning I love it, why not have some bonus grunt low when you want it when playing around turning hills etc. I dont mind maintaining and cleaning it now and then. Those are great kits with the power valve or going non, whichever way you want to go. It will make you a great duner R.

Thanks for your input. So other than some cost savings what is the advantage or disadvantage of the 363 vs 370? Sounds like the power valve would be something i would choose to go with any thing that improves low end grunt is a plus for me.

[rjt500r]

My trx 7 port 330 just came back from the dunes and I was really pleased.  Glad I didn't go with the trx9.

Thanks, his site advertises the trx 7 as an mx setup is it all low end ?

[rjt500r]

MADE IN USA! Eddie sells great stuff. I have his 330+4. Trx9 port. Rips!

Thanks, started out looking at the 330 but for a little more money its hard to pass up more power.

[Bowtie316]

Thanks, his site advertises the trx 7 as an mx setup is it all low end ?

No, if anything I could still use a little more low end, I would imagine you would gain that with a 350 or 370. I'll try to find a good video and post it up.  

Be careful adding a +4 stroke, it brings the port timing up and can kill bottom end, been there done that.  I now hear that Eddie will cast a cylinder with more sleeve up top to correct this, but it has to be thought out in advance and set up by another builder, I don't think ESR will mess with it.

[Bowtie316]

Here is a link to my thread, I just added a short drag video.  More video to follow.

http://trx250r.org/threads/4011-My-88-stock-frame-rebuild-cleanup?p=43014#post43014

[rjt500r]

Be careful adding a +4 stroke, it brings the port timing up and can kill bottom end, been there done that.  I now hear that Eddie will cast a cylinder with more sleeve up top to correct this, but it has to be thought out in advance and set up by another builder, I don't think ESR will mess with it.[/QUOTE]

I guess that is really my question , is this package setup dialed in off the shelf or does it need tweaked for it's full potential? The ESR site calls the setup" 4- stroke killer" with pipe and porting options and the +5mm crank, carb, power valve, reed valve. Arlan and I talked about the ESR 350cc, but he also showed me some dyno numbers for the Puma 408cc.

[Pumashine]

I rode 330's and 350's in the sand for years before the Puma came out. Was always wanting more power. The Puma is the best cylinder you can get. Its worth the extra you have to pay for crank balance IMO. Best part is you will never need more power especially with the 4mil 431. The cylinders are cast differently for the stock stroke 408 and the 4 mill 431. Port times are not changed if you get the mating crank. Having a building putting it together or as you call it tweaking to get the correct port heights is also worth the extra cost. Never had a 350 put a white face on me.

[Bowtie316]

Be careful adding a +4 stroke, it brings the port timing up and can kill bottom end, been there done that.  I now hear that Eddie will cast a cylinder with more sleeve up top to correct this, but it has to be thought out in advance and set up by another builder, I don't think ESR will mess with it.

I guess that is really my question , is this package setup dialed in off the shelf or does it need tweaked for it's full potential? The ESR site calls the setup" 4- stroke killer" with pipe and porting options and the +5mm crank, carb, power valve, reed valve. Arlan and I talked about the ESR 350cc, but he also showed me some dyno numbers for the Puma 408cc.[/QUOTE]

I should have said be careful with the extra stroke on 'ESR' cylinders, they were normally cast for stock stroke.  I have heard that the cylinder you get for a 330 trx9 will be the same as the one you get for the 330 +4mil or 344, which would put the port timing higher on the 344.  I had a K&T built 344 that had too much timing and not enough bottom end grunt.  I was told by Arlen and others that it was because it was due to the extra stroke.  Don't get me wrong, it "killed" some 4 strokes, but it wasn't much fun to ride. If you go ESR, and you want the extra stroke, make sure it's one of the cylinders that he cast long in order to do it right.

The spynx and puma cylinders are cast such that they can match either stroke no problem.

[rjt500r]

I rode 330's and 350's in the sand for years before the Puma came out. Was always wanting more power. The Puma is the best cylinder you can get. Its worth the extra you have to pay for crank balance IMO. Best part is you will never need more power especially with the 4mil 431. The cylinders are cast differently for the stock stroke 408 and the 4 mill 431. Port times are not changed if you get the mating crank. Having a building putting it together or as you call it tweaking to get the correct port heights is also worth the extra cost. Never had a 350 put a white face on me.

Thanks for the info, it seems no matter what i have i want a little more power, i thought my Zilla ran pretty hard until i had Jerry Hall port the cylinder, big improvement, really happy with Jerry's work. Honestly the Puma is what i want, just a little cautious about going too big and having reliability issues.