At any rate....to make a long story even longer.... I recently purchased another 250R

this time, an 88 trx250r with an ESR330R kit (or so I thought)...

actually... this bike has a LOT of very nice goodies....unknown to the last owner.... like CR Ignition and TMXX 41.5 Taper Bored Carb.... center mount TRX-11 ESR pipe (very top end oriented), and Eddies own billet mounts for the coil, pipe, etc... not to mention his TRX-9 Porting and his own ported ESR Billet Reed cage and cage Spacer....

when you add all of this up....you have a very potent machine for the price...... the only problem is... and again, unknown to me... was sleeping inside of that ESR330 engine was another upgrade.... Eddies own stroked/blue printed crank..... for which the 330 cylinder had been ported to match the small but potent 2mil stroker........

the 330 kit comes with an interhcangeable dome head....for those who have never run 2-strokes... this is a very nice billet addition to any machine.....it includes a nice billet head with O-ring gaskets... yep, no more blown head gaskets or copper gasket spray to help them seal.... and also, a cheap but very effective replaceable dome....for about $45, you can change from pump gas to race fuel...in about 20 minutes or less without changing gaskets......the trick is.... and here is where the issue began.... is you must specify stock or stroked engine...... and here is why

on 4-strokes.... you either run a stroker piston (wrist pin relocated) or base plate spacer or use shorter rod (HR drop in crank) or a combination of the above..... the best of course is to run a long rod stroker and compensate using piston/spacers/longer timing chain, etc.... lot of work.....and not everyone does it.....

on a 2-stroke... the stroke must be matched to the porting..... or she wont run well..... meaning whoever ports your engine....has to match the ports to the BDC position of the top of the piston.... and also match the exhaust port timing.... but the real issue that caught me was this....you can either space up the cylinder.. and in this case my machine runs the std .190" ESR spacer for his 330 kit and long rod machine..... but, and this is a big BUTTTT... if you run a 2mil stroker.... you dont run a taller spacer for this cylinder because it was ported for the .190" spacer block.... you run a special 2mil stroker DOME....a dome which has been recessed an additional .040" (approx 1.0mm) to compensate for the 2mil stroker... cuzz the piston is now pronounced (meaning protruding above the deck) exactly 1.0mm with this kit....so w/o running a stroker dome..... your quench area is about ZERO..... needless to say.... not good...

so.....here I am.... having a bear of a time trying to kick this high comp race machine over..... so I decide to order up an ESR pump gas dome......for mine and my son's 310R.... no biggie, not all that expensive...given the fact both of these machines can now run pump fuel and kick over easier......

ordered 1600 hours on one day......they arrived the very next day.... ESR prides themselves on FAST delivery... and almost everything gets shipped out the very same day...even if ordered late afternoon.... okay... so, the bike closest to my tools was my son's 310R... so I decide to check it out.... drain the coolant...take off the rad hose... 6 head bolts and a support bracket...and done.... head is off.... dome pops out (the dome is also O-ring sealed and come with a new upper O-ring for ease of replacement).... I compare the old dome to new dome.... put piston at TDC just to check the dome width, etc.... everything seems good.... so I button her back up....... took about an hour since I was also cooking dinner and taking measurements...etc....... kicked her over.... still a bear to kick though.... but easier than before.... all is good.... she fired up.... reved up.... done...

next day came my 330R turn.... same deal.... drain coolant.. remove head... pop out dome... insert new dome... width or bore was 78mm... all is good... everything looked fine... buttoned her up... kicked her over....and thought... WTF..

this was suppose to be a PUMP gas dome.... now mind you ESR are stamped on the top of the dome the bore and compression.... hence... 330 PUMP carved in mine... 330 RACE in the one I took out.... but man O man she did not seem any easier to kick over...if not harder..... oh well... a tug behind my truck and she was off and running.... like a raped ape...... and with PUMP FUEL no less.....

well.....such is life.... take her to the beach..... she is a BEAR to kick over... hafta pull start her... .which was NOT an easy task...... she fires up eventually... and off to the dunes I go.... several of us... all dying to see if this thing was fast or not.... well... yes, she is fast... my son thought he had the fastest bike for a while...and he did beat everyone in our group.....till he lined up with this 345R..... man O man..... coming from someone that has ridden his share of racing 2-bangers......when this thing came on the pipe......she was GOOONE..... that's if you could hold on.... I let one of my buddies ride her...he made one pass........ looked pretty good.... then he parked her.... said "no way"..... .he wasnt used to a bike that you hafta lean way over the handlebars when you shift.......it scared him enough to park it.... lol... and this guy races his YFZ450R all day...... I made a few passes......fast bike... needs a set of paddles matched to the machine though..... but still fast...... then on my last pass....(last pass cuzz she blew, not cuzz I was done...lol) she seized up on me.... typical 2-stroke seizure.... takes just a few seconds.... they start to lose power then STOP..... she was towed back to camp.....

I knew she seized...just didnt know why...... and I was curious to tear in to her..... back at home I did just that..... when I got down to the piston.....I thought... dang.... lot of damage for what I thought might have been sand in intake....or running a bit too lean..... and the dome looked perfect... nice medium brown color.... couldnt have been lean.... then I noticed a polished crank in the bottom end..... and im thinking... that aint OEM.... seen enough of those to know the difference.... and the big end bearing journal (lower rod journal) had been shaved..... humm.... this looks like a STROKER crank.... you shave the journal to compensate for space inside the cases....makes a 2-mil stroker more of a "drop in" type...... not that it matters cuzz you have to remove and machine the cases for the 330 kit anyways.....oh well....

I called ESR after inspecting my engine and he came to the same conclusion I did.... the piston was pronounced 1mm/.040"... I thought I needed a taller spacer for this cylinder.....he said no..... the cylinder was ported to match a 74mm stroker engine..... so that stays the same.....he said what I needed was a 2mil stroker DOME..... and the reason why my engine seized was simple.....I purchased and installed a standard stroke pump gas dome... this created a tremendously tight quench area...not to mention more compression than most people ever want to kick over..... and you combine this tight of quench..... with high comp and PUMP fuel... and guess what.... yep.... "Houston, we have a problem"... lol


at any rate...she is all back together now.... bored to next size of 77.0mm with new pump gas STROKER dome...lol, new piston and new reeds... since one of my reeds had been broken.....(probably another reason for the hard starting issues)... at any rate...she is running like a CHAMP.....

oh.....I added a set of Full Flight racing +2" A-arms and SS brake lines while she was down...... she needed to be wider for the dunes...lol



my next major purchase is a set of paddles....just not sure what to go with at this point...im thinking the 9 paddle Brats.. I love my 6 paddle Brats on my 450R....but they are not enough for this 345cc machine.....


here are some pics.... nothing to write home about.... just another 2-banger broke and fixed....



some carnage....

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broken Reed

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2mil stroker crank (note the surfaced lower rod journal)... we call that a CLUE...lol

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This is what a 2mil stroker does.... piston is pronounced exactly 1mm

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here is a dome comparison... both are ESR330 pump gas domes.... the right one is for a 2mil stroker...

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one of the very nice nice nice things about 2-bangers.... is O-RING Heads...

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huge TMXX Mikuni 41.5 bored carb

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an ESR ported Reed Cage.....hard to see how nice this billet is ported with my camera...sorry

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my new A-arms....

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Did I mention just how FAT this ESR TRX-11 pipe is....lol

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at any rate......enjoy

** Moved to Engine section for INFO only, can move back to 'other' section if creates an issue. Mgnt

Love seeing some ole' 250r engine guts.

Ya never know what you're getting in a 250r, it seems. They've all (or most anyway) been owned by such a long chain of owners, there could be anything in there.

Glad you got it all sorted out.

damn man, sounds like you had some trouble at first but she runs like a raped ape. Either way, its always "fun" to tinker with something to get it running right.

I got a friend who has a high comp 310 in his r. I believe its strictly bore. I rode it and wasnt too impressed. It was built by ct. Maybe im just used to my r.

Nice info Greg. I had a esr 350 bore (78mm) and the 4mm stroker (370cc's) and I got to tell you, I wasnt too big on the idea of the piston coming out of the cylinder like that. I had quite a bit of trouble keeping it reliable. I tried many things to help it out and in the end wasnt all that happy with that ticking time bomb. I had my therories why I felt it wasnt a great idea having it come out as far as it did.

My next build was the 425 PSI power valve setup and liked it more than the esr stroker 370 kit I had previously. Needless to say the esr setup had more top and the psi had ALOT more bottom and mid. Piston in the psi kit was something like 86 massive mm's....lol. I think it was actually stock stroke and all bore....hard to remember now....

I also had an ESR 330 kit like yours without the stroker with a trx11 port and trx11 pipe. Had ZERO bottom end with a rediculous peaky top end...as you would assume!

That wicked two stroke power band is awesome for sure. Hey I got a few 250r pipes hanging around here I dont use anymore...want them? I trade you for a badge and a pistol...lol no but really you can just have them if you are interested. I may have a bunch of stuff for the old R. I think I have a few boxes with 250r stuff. I will look for them and hit you up

that would be great Gar..... let me know if I have anything you could use in trade....

ya...she is a bit 'peaky' to say the least...but still dunable...... not what I would call a 'trail' bike...lol

I just hate kicking these big bore machines over.... I mean.... DAAAAAAAAAAAAAAM.... I cant imagine what a 370 or bigger would feel like...this 330 is about my LIMIT for kicking......

but hey, my first all out MX bike was an old 74 Elsinore 125.... Piston port, 28mm Keihin carb, 4" of rear travel suspension... I mean...the WORKS...LOL I cant get the feel of a 2-banger out of my system..... but I hafta say.....the clutch pull on this machine is off the chart......so 'was' the thumb throttle..... I tore her apart and she is only sporting the factory 88 HD springs...but man O many they are QUITE a bit stiffer than my 450r clutch..... and the guy before me used an 86 thumb throttle, because the 'cam' actuation on these had a much longer PULL to them..... so it would activate this massive 41.5 mm TMXX carb.... whereas the stock 88 thumb throttle will barely move enough to give her 3/4 throttle.... well, until I modded it.... now at least the thumb throttle is at least 'OK' where it was painful at best using the older 86 thumb throttles....

well......I gotta go outside and finish cleaning out my hauler..... getting ready for another 10day trip to the coast..... cya and happy 4th

Man, you guys are waaaayyy beyond me. Interresting stuff to read tho. Nice thread and pics.

Ahh the ol whale pipe! Gotta love em!

Pretty cool info.... got to ask though how is it you didn't notice the piston out the hole the first time? A friend of mine has a 86R (89 crank with spacer) and bought the new ESR 330 cylinder (not ProX) and ported for mid then he sent it off to C-Leigh for a top end port job. Now with the spacer and and 330 cylinder they cut off most of the lower skirt so the cases didn't have to be clearanced out. Sounds odd, but works great. He too has a 41 carb and trx11 center mount pipe. And like you said he too has to sit up on the tank during up shifts :)

Well....thats a good question..... mostly because I never checked the piston on this machine...

I did much more 'testing' on the son's 310 to make sure the domes were compatible and the proper size, etc.... after I installed his and it all went well.... I just kinda 'eyeballed' my 330 and never put the piston at TDC.... as a matter of fact.... it only took like 15 min to drain the coolant, take out the plug, the top engine mount and six head bolts....then I just popped out the old dome and put in the new one.... I never checked the stroke on my machine.... live and learn when you buy a used item.....no telling what is inside that engine....

and yes, Eddie sells two different 330 kits.....one is a bolt on, where they chop/grind off the lower skirts so you dont have to machine the cases.....this is the largest of the ESR "bolt on" kits..... the problem of course is that you cut down your number of bore sizes by double...meaning you only get TWO re-bores out of here...cuzz the skirt has been cut.... if you go with the longer process....where the cases have to be machined to accept the larger skirt...... you get (4) additional bores out of here instead of just (2).... from the stock 330 kit w/76.0mm bore.....all the way to 78.0 mm bore.... in 0.5mm increments.... so ya, its a lot more work.... but it pays off in the long run if you keep the engine long enough and need to bore a few times.....(its a two-stroke, it happens...lol)

does your buddy complain about how STIFF this TMXX carb is? does anyone make a softer spring? im gonna take mine out and try and match it up at the local machine shop........ I need something a bit easier..... this is probably where the twist throttle comes in to play....lol


did I mention she is a PITA to kick over? lol

The TRX-11 pipe..........I remember when my son ran one on his 280cc ride, now that was a peaky sumbitch. I think the HP gain is more than offset from the wind drag of the phat bastard pipe.........lol.

It does have that cool factor you cant resist.

Could the old head be recut to work with pump gas?

Yea theres something about having that massive tuba hanging off the side of the bike!

I loved watching peoples faces when I pulled up and they see those huge pipes like the 11, the whale, and a few custom shearers that I had....

Even if they didnt make more power, they sure looked intimidating....lol



You could cut the domes but for what they sell them for, it would probably cost you more to remachine it then to buy it from esr new.


I never fell for the lazy big bore kits. Id rather just take the engine down and machine the cases and be done with it. Just for the reasons Greg touched on. Their just too easy of a engine to work on not too.

Yeah I think it is the most simplest of jobs that can turn around and bite us in the azz and reminds us that even a small job stills needs some for thought applied to it. It gets us every time I think.

Yes this thumb throttle is killer stiff, and yep that is where the twist makes a word of difference. He rides it mostly and doesn't complain about it... so we haven't looked into any softer return spring or slide spring.

Yep the 2 over bores are the major down side to the short skirt.. but his bike, his motor.... his money... if you get my drift.

If he feels the thumb throttle is a bit much.....(and yes, it was for a WHOOS like me....lol).... he can switch it over to an 88/89 thumb throttle, but he will hafta machine/grind on the internal housing components (like the throttle stop) in order to have enough movement to move that 41.5mm slide all the way up / down...... it was well worth it if you ask me.....


ya...I like the 'looks' of the pipe....and even like that killer HIT .... or maybe it aint a hit at all....but just runs so poor before you get on the pipe that it just feels like a strong hit... who knows....lol but, it DOES get in the way of these forward kicking machines.....



later...

I wonder how the trx11 would compare to an ftz top end pipe. I have one that I ran on my 270cc setup, and didn't like how I had to clutch it so often. One day I might finish my 350pv and I have been eyeing up that bad boy, I just have the fear of burning down the motor with how quickly it can go lean. It sucks to see you motor go down.

hey man super nice 250r. Ya should have dont a compression check before running it though. :/ Glad you got it running! Had it on the dyno?i bet that thing flies!

Hey hows my leak detector doing over there Greg? dont be fallin in love with it...lol

Oh Fudge.....I almost forgot...lol


it was kinda confusing at first..... but it's pointing to a crank seal..... which I kinda suspected....

ill get that back to ya shortly...












(maybe)....lol






















[size="1"][/size]

Arent you guys a little old for the org?


Just saying hi



Blackie

these conversations make me want a 250R!

Sounds like you learned and proved a major lesson. Assume nothing and always check yourself. Not busting your balls, just saying. Any motor I have ever bought, complete or not, I have tore down and spec'd out myself because not everyone is truthful or even know what they have.

Gar....if your listening... your item is packaged up and ready for the trip home.....

might take a day or two before my GF can get her to the UPS store however.....

dont worry....it's coming back at ya....lol

Hey Greg post some pics of that beast (the whole thing). I've been keeping an eye out for a decent used 250R for my boy, he has been growing like a weed and looks like grape ape on his blaster now. Any suggestions on what to look for or stay away from while looking?