Esr 330

[arlaunch]

I found an engine on craigslist for sale. Apparently it has been fully rebuild and has an ESR 330 cylinder head on it. Unfortunately i am not sure if it is the bolt on kit or the case machine version.

Either way.... I understand the difference. I think it started out as a 1986 TRX then had the bottom professionally rebuilt and a long rod system added. I am going to look at it tomorrow.

Anyway.... I have looked around through countless threads of blah, blah, blah and just thought i would check in here to see if anybody had anything negative to say about a 330 kit in a 1985 250R ATC.

I have heard all kinds of things about overheating. From what i have heard it seems most of the issues where due to poor carb settings coupled with incorrect two stroke oil mixtures.

I will check and see what this great community says in the morning. I will likely dive right in head first and buy the engine though. It is a good deal.

Thank you,

>>>>>>>

[BOB MARLIN]

There is a thread from a couple weeks ago that I was part of with alot of info in it. You could do a search for it. The short story is, I have the esr 330 -NON bolt on. They run HOT no matter what jetting you have, or what oil you run, or what ratio it is, or even if you have the larger aftermarket rads with strait water in them- but they don't seem to seize because of it- if you keep an eye on it. I just don't think you can abuse it like you could with a stock motor. It is a HUGE power difference from stock. Also they are a tight fit. You can't use a standard spark plug. It will hit the frame. The shorty plugs you have to use are about $18 a piece. These engines seem to run allot cooler in the quads where there is more air flow and even bigger rads.
But even after all this, I would never go back to a stock jug. Once you have a big bore you get spoiled.

[arlaunch]

Thank you Bob,

In an attempt to give something back to the community here i will likely start a new thread with pictures through the removal of stock engine and the installation of the new engine.

I am still scratching my head if the 330 will bolt onto the headstay motor mount?

Thanks for the reply.

[BOB MARLIN]

No, it won't bolt up to the headstay with out making some kind of alteration. I really don't think you need it. I don't use it and I have not seen anyone else with the big bore use it either.

[The_Steve_Man]

Bob what pipe are you running? How hard you ride it? I am going to build one and eventully get Arlan at LED to build me a pipe but not sure when.

[BOB MARLIN]

I don't consider myself a hard rider. Not even close compared to some of the guys I've ridden with.

I am running just a FMF fatty, and it actually runs pretty good with that pipe. I do think if I were running a pipe that was better suited for a big bore engine it might run a bit cooler. I would like to try an esr atc5 pipe on it . One thing I have a problem with is that my aftermarket rads hit the fmf as it is. The esr and some of the others are bigger in the expansion area of the pipe and might interfere more.

[The_Steve_Man]

The FMF is definitely a restictive pipe. I put one on my ported stock cylinder and it took power away compaired to my CT pipe. The head pipe is smaller in diameter moving the power lower in the rpms and taking away from overall power.
I think I will definitelygive the ESR pipe a try. I do ride fairly hard sometimes.

[RIDE-RED 250r]

I don't know why you say you cannot use the head stay on the big bore Bob, I use mine with no issues or mods needed. Maybe earlier ESR's that was the case???

The ESR ATC5 pipe seems to work very well with my 350. I think you would be hard pressed to beat the performance of the ESR pipe in the ATC for the same money.

[yaegerb]

Bob what pipe are you running? How hard you ride it? I am going to build one and eventully get Arlan at LED to build me a pipe but not sure when.

Good Luck, he doesn't have the ATC 250R jig anymore and last time I spoke with him he didn't seem too interested in building another one.

[BOB MARLIN]

My headstay was close but not quite close enough to work as is with out binding. I've also talked to a few people that can use the standard plug. I definatly can't. I think there was a change in the head somewhere along the line. My plug is strait up. I think at one time they were slightly angled and cleared the frame. Mine is about a year and a half old. I don't know if that makes it a newer one or an older one.

Maybe it's because I am running a long rod engine making everything a bit taller ?.

[The_Steve_Man]

I think he had a lot if tire kickers. Myself included. I was just about ready to pull the trigger on one and lost my job. He said he will build one for $850 and it would be worth every penny.

[yaegerb]

I think he had a lot if tire kickers. Myself included. I was just about ready to pull the trigger on one and lost my job. He said he will build one for $850 and it would be worth every penny.

Wow, that's not the price I got. Let me know if you end up going that route and you get him to consider making one again.

[The_Steve_Man]

You maybe talking about production pipes. He used to make them. Now he will only do custom pipes.

[RIDE-RED 250r]

My headstay was close but not quite close enough to work as is with out binding. I've also talked to a few people that can use the standard plug. I definatly can't. I think there was a change in the head somewhere along the line. My plug is strait up. I think at one time they were slightly angled and cleared the frame. Mine is about a year and a half old. I don't know if that makes it a newer one or an older one.

Maybe it's because I am running a long rod engine making everything a bit taller ?.


Bingo! I would guarantee that is why. :) Being the ATC never got the long rod, that would be why you cannot used the head stay.

Being I am running the old short rod setup I am able to run std plugs but I cannot run the large, stiff spark plug caps. I improvised a small 90 deg cap commonly found on chainsaws and weed eaters. Works like a champ and have not had any issues with it at all.

[BOB MARLIN]

Yay!
Mystery solved !

[hatc200x1]

Bob, another point about the long rod set up, sense you have a spacer, that would effectively raise the cylinder, raising the exhaust port, and making the pipe sit higher right? Could that be why your FMF pipe is hitting your rads?

[BOB MARLIN]

Ya hat,
I thought of that to too!. That spacer ain't all that thick but it sure gets in the way.
The pipe fits fine with the stock rads, it just hits the larger aftermarket ones. The larger rads only pulled out about 5 degrees anyway. But I need all I can get.

[250rRoostmaster]

You maybe talking about production pipes. He used to make them. Now he will only do custom pipes.

I live 20 mins from his shop. He needs a bike there to build the pipes so anybody that needs a custom pipe I might be able to swing my trike out there for him to use for you. Just throwing it out there.. His pipes kick ass

[arlaunch]

I ended up going to have a look yesterday.

This fellow said he had it professionally rebuilt and it costed around $2200.

I am sure this was the case but.....

The bottom end looked mediocre (not painted or smoothed) The ESR 330 head was beautiful and brand spanking new.

Something inside me told me to walk away. To bad.. It was an hour drive up there to look at it.

Back to the drawing board. Going to look at a bottom end today of a 1986 TRX 250 that has been completely overhauled and what looks to have been done right. It was taken apart, blasted and cerekoted black. Looks gorgeous.

I will likely purchase it and stay with a 310 or under.

What i have learned from this is.... Anything over the stock 250cc cylinder head is better to be ran off of race fuel or a race fuel mix for cooling purposes.

If you have a long rod kit in your ATC the head stay mount will not line up.

I have also learned that hanging out on the couch, 330cc's sounds cool. Out in the world it may be to much power for me?

In addition to that, this forum has some of the best people around.

Thanks fella's.

I may just go with the ProX 250cc head from CT.

I just want supreme reliability and to use the non ethanol pump gas from the station down the road.

I am older now and just want to build pristine machines. I hardly ride anymore. Seems i am most interested in these things as beautiful collector items in perfect shape.

[250rRoostmaster]

I ended up going to have a look yesterday.

This fellow said he had it professionally rebuilt and it costed around $2200.

I am sure this was the case but.....

The bottom end looked mediocre (not painted or smoothed) The ESR 330 head was beautiful and brand spanking new.

Something inside me told me to walk away. To bad.. It was an hour drive up there to look at it.

Back to the drawing board. Going to look at a bottom end today of a 1986 TRX 250 that has been completely overhauled and what looks to have been done right. It was taken apart, blasted and cerekoted black. Looks gorgeous.

I will likely purchase it and stay with a 310 or under.

What i have learned from this is.... Anything over the stock 250cc cylinder head is better to be ran off of race fuel or a race fuel mix for cooling purposes.

If you have a long rod kit in your ATC the head stay mount will not line up.

I have also learned that hanging out on the couch, 330cc's sounds cool. Out in the world it may be to much power for me?

In addition to that, this forum has some of the best people around.

Thanks fella's.

I may just go with the ProX 250cc head from CT.

I just want supreme reliability and to use the non ethanol pump gas from the station down the road.

I am older now and just want to build pristine machines. I hardly ride anymore. Seems i am most interested in these things as beautiful collector items in perfect shape.




LOL just noticed your from Oregon City!! So am I haha

[yaegerb]

I ended up going to have a look yesterday.

This fellow said he had it professionally rebuilt and it costed around $2200.

I am sure this was the case but.....

The bottom end looked mediocre (not painted or smoothed) The ESR 330 head was beautiful and brand spanking new.

Something inside me told me to walk away. To bad.. It was an hour drive up there to look at it.

Back to the drawing board. Going to look at a bottom end today of a 1986 TRX 250 that has been completely overhauled and what looks to have been done right. It was taken apart, blasted and cerekoted black. Looks gorgeous.

I will likely purchase it and stay with a 310 or under.

What i have learned from this is.... Anything over the stock 250cc cylinder head is better to be ran off of race fuel or a race fuel mix for cooling purposes.

If you have a long rod kit in your ATC the head stay mount will not line up.

I have also learned that hanging out on the couch, 330cc's sounds cool. Out in the world it may be to much power for me?

In addition to that, this forum has some of the best people around.

Thanks fella's.

I may just go with the ProX 250cc head from CT.

I just want supreme reliability and to use the non ethanol pump gas from the station down the road.

I am older now and just want to build pristine machines. I hardly ride anymore. Seems i am most interested in these things as beautiful collector items in perfect shape.

I have been told by many engine builders and racers that a properly ported/tuned/geared OEM 250R motor has more power than you will ever use. After racing for 1 season, I agree.

[The_Steve_Man]

I live 20 mins from his shop. He needs a bike there to build the pipes so anybody that needs a custom pipe I might be able to swing my trike out there for him to use for you. Just throwing it out there.. His pipes kick ass

Thanks. I don't when I would be able to get now. I saw that you had one of his pipes. I know they are worth every penny. One day I will have one.

My ported stock cylinder does great on the track. I ran one track that could have used more.

[BOB MARLIN]

If nothing else, this has been one of the more informed post I've seen here in quite some time. No arguing or bitching. Just good info.

[The_Steve_Man]

It got a little off topic. But definitely a rational discussion.

[RIDE-RED 250r]

Yeah I agree Bob...

Thanks to you and your experience with the spacer you have posted and how it makes things a little more difficult in some ways on the ATC, I'm not so sure I want to build a stroker any more. I have kicked around the idea that my next hot rod may possibly be a +4 crank with the 78mm (350 on stock crank) top end... With your FMF pipe causing a bit of interference with the rads I'm pretty sure getting my ESR pipe to mount comfortably would take a bit more massaging. I'm sure it can be made to work, I am just not as skilled and equipped as some of the guys on here that fabricate some of the works of art they have.

Not that I really NEED more power than what my rig currently delivers now......... Wait a sec... what did I just say???!!!! HERESY! LOL! :)

[jays375]

Give BDT Motorsports a call.The do awesome work and build nice pipes.They know a lot about 250R engines.