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Turn my bike into a 250f killer. Questions.

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I have a 2004 RM 125. I am sending the motor to Eric Gorr soon for the 144 conversion, I will be running pump gas with it.  Will this be able to out pull the 250f's? What gearing combo should I run? Can I advance the timing 2 degrees without having to worry about  a melt down?

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As the saying goes there's no replacement for displacement, in a straight line, you will have a hard time pulling 250f's without it being ported and having the "works" done to it, but if your on a track, horsepower is about the least important thing if you can ride it well, being a light 125 you should've able to out corner just about any 250f

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I have a 2004 RM 125. I am sending the motor to Eric Gorr soon for the 144 conversion, I will be running pump gas with it. Will this be able to out pull the 250f's? What gearing combo should I run? Can I advance the timing 2 degrees without having to worry about a melt down?

here the facts, 250f's aren't that fast, it's all torque. 125's aren't too fast but with light work will be faster. For example a bbk or your 144 kit should give you the edge on 250f's.

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Ok, send the motor to someone besides Eric Gorr. Spend some more money and get iy done right. Yea he's a nice guy and all, but I don't think he really knows what he is doing.

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Ok, send the motor to someone besides Eric Gorr. Spend some more money and get iy done right. Yea he's a nice guy and all, but I don't think he really knows what he is doing.

quick question.. Are you stupid?
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Lolololololol. Ok. So, heres the story. I have made a thread about it. I had a kx125, I thought "hey, I need to get it replated any way, so ill just spend 100 more and make it a 144 through Eric Gorr, Genius!" Well long story short he had it running at a 17.1 compression ratio, this was after I sent the head back to him saying that it was knocking and pinging like crazy. He said that I wasn't jetting it rich enough. Dude from TDCmotocross hooked me up and got me straight. Sad thing was, he wasn't even surprised at the ratio Eric had it running at. He says he sees it all the time. So, spend more money now, to spend less later. But it's your call.

Edited by gscx

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Lolololololol. Ok. So, heres the story. I have made a thread about it. I had a kx125, I thought "hey, I need to get it replated any way, so ill just spend 100 more and make it a 144 through Eric Gorr, Genius!" Well long story short he had it running at a 17.1 compression ratio, this was after I sent the head back to him saying that it was knocking and pinging like crazy. He said that I wasn't jetting it rich enough. Dude from TDCmotocross hooked me up and got me straight. Sad thing was, he wasn't even surprised at the ratio Eric had it running at. He says he sees it all the time. So, spend more money now, to spend less later. But it's your call.

I've used Eric gorr for a few 2ts and have had great succes. To each their own.

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I have a 2004 RM 125. I am sending the motor to Eric Gorr soon for the 144 conversion, I will be running pump gas with it. Will this be able to out pull the 250f's? What gearing combo should I run? Can I advance the timing 2 degrees without having to worry about a melt down?

the 144 kit alone won't throw them 250's in the dust but what kind of budget do you have? I can help you out with a few ideas on how to make that thing just destroy the 250's

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the 144 kit alone won't throw them 250's in the dust but what kind of budget do you have? I can help you out with a few ideas on how to make that thing just destroy the 250's

Trying to keep it under $1000. That's still pushing it for me.  What ideas did you have in mind?

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I had Eric do a 144 for me last summer, I liked the guy and liked the value of his kit, but it was an absolute mess, and in the end I had to have his work repaired by a local shop. Eventually the Gorr kit performed as promised, but I was out over 1000 bucks by the time I got to really ride the thing. Quality control seemed to be the issue more than anything else, but I was very disappointed with the whole experience. It took over a month ( I was told a week to ten days), engine came back assembled poorly/improperly, pv linkage arm had been bent, then cracked and epoxied back together, clutch hub spun itself off, (yep, on a ride with my son, first ride on the 144, got stranded, had to push the bike and go home early, they forgot the lock washer), WP cover wasn't sealed, nothing was tourqued, and the final major issue was I had asked him if he could repair a bad stud for me, no problem he said. Something bad happened because the hole that the "new" stud was in looked like it had three holes with the stud epoxied in the middle. I assume the drill press got away from the lackie that was supposed to fix it. They used the same crap epoxy and threw the stud in and sent it to me. Every time I rode I noticed an air leak at that stud, I would tighten it down, but by the end of the ride it would loosen. Come to find out the stud was pulling up every time I tourqued it down. It cost me almost as much as the kit did to have it repaired again, just properly this time.

I intended to state simply you get what you pay for, seems I'm still a little frustrated about my 144 and I don't even have the bike anymore...:)

I would use Millenium for re-plating, I'd even use Eric for porting, but I would do a LOT of research on other 144 kits and see what was best if I wanted to build a 250f killer. With what I spent in the end, I could have bought any 144 kit out there, YMMV.

Edited by poldies4

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I cant speak from first hand expiriance but I have seen a good friend of mine pretty much throw his EG stff in the garbage. Had 6hrs on it before the probs starting pouring in. Needless to say its now got the stock stuff back in with zero probs. I have heard both positive and negative things about EG.

On the other hand, I have dealt with Melenium before and was more than happy. Excellent customer service and turn around time. They re-did my 02 125 cylinder after a C clip come off and destoryed it.

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Trying to keep it under $1000. That's still pushing it for me. What ideas did you have in mind?

id go with the 144 kit as long as you can get it properly done. Then I'd go with a pro circuit pipe and shorty silencer. That will take up a lot of your budget! But after that spend the rest on bolt on. Go get V-Force 3 reeds. A high pressure rad cap to keep that bike a little bit cooler when it's running the big bore in it and then I'd pop a 250 2 stroke carb on it. Let me no what you think.

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id go with the 144 kit as long as you can get it properly done. Then I'd go with a pro circuit pipe and shorty silencer. That will take up a lot of your budget! But after that spend the rest on bolt on. Go get V-Force 3 reeds. A high pressure rad cap to keep that bike a little bit cooler when it's running the big bore in it and then I'd pop a 250 2 stroke carb on it. Let me no what you think.

 

id go with the 144 kit as long as you can get it properly done. Then I'd go with a pro circuit pipe and shorty silencer. That will take up a lot of your budget! But after that spend the rest on bolt on. Go get V-Force 3 reeds. A high pressure rad cap to keep that bike a little bit cooler when it's running the big bore in it and then I'd pop a 250 2 stroke carb on it. Let me no what you think.

So far it has a Bill's pipe and shorty silencer, Boyesen reeds, clutch kit, And a Boyesen ignition cover + Boyesen clutch cover for the  looks.  So I planned on just getting a EG 144 for more power now.  And im a little weary about the high pressure radiator cap, heard  a few stories of people constantly blowing head gaskets with them(happened to my cousin as well)

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So far it has a Bill's pipe and shorty silencer, Boyesen reeds, clutch kit, And a Boyesen ignition cover + Boyesen clutch cover for the looks. So I planned on just getting a EG 144 for more power now. And im a little weary about the high pressure radiator cap, heard a few stories of people constantly blowing head gaskets with them(happened to my cousin as well)

if your worried about blowing a head gasket buy a thicker gasket and then shave the head to adjust the squish band or just run 2 head gaskets and shave the head.

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I'm waiting on an Eric Gore top end kit for my bike ATM. Been about 4/5 weeks. Haven't herd a thing. So much for International customers getting quick turn around times.

 

I have another engine builder doing the engine. He was pretty keen to do the head on mine himself. I can see why now lol. I got a VHM head. He'll be doing a complete bottom end rebuild as well.

More than likely going with the DEP 144 system but not 100% yet. May be HGS or even an FMF Fatty yet. 

I have a Boysen RAD valve. Boysen engine covers as well. Hinson clutch basket, New OEM clutch kit Including springs and a Lectron Carby. All brand new and still in the packages.

Custom Ignition mapping done on a dyno.

 

I have oversized radiators. Cheap as chips and Chinese but much to my surprise they are really good. I'll be putting a set on my 07 model when I build that as well. cost around $120.00 AUD with Silicon hoses. They'll cost less with the USD. A stock radiator is around $650.00 here and that's only one side.

Edited by AddictedToBling

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For those who race and are serious about getting the maximum, need to check out TDC 2 Stroke Performance. 

 

TDC 2 Stroke goes way further into R&D than most all 2 stroke "experts" in this country. He's almost got me scratching the surface of how he goes about his work. Reading stuff like this will give you a slight clue on how he operates. http://www.epi-eng.com/piston_engine_technology/bmep_performance_yardstick.htm

 

If you take the time to read some of this you'll see measurements of BAR Some experts said a normally aspirated motor would never go above 15 BAR well the Nascar Cup guys exceded that with a pushrod engine at 15.4 BAR. Considering pnuematic controlled valves in a 19,500 rpm Formula 1 motor was "below" this at 15.14 BAR

 

So now after putting all this impressiveness out there you'll never guess who the "King" is in this department?

 

How about a 125cc 2 stroke!! Hence the BMEP of 17 bar for the Aprilia RSA125.I seems to remember having read that Jan Thiel said they reached a max of 56,5hp ( crankshaft power ) at Aprilia. 

 

Interesting stuff but this is why TDC is still refining and putting in hours a day on the dyno. Knowing there is more to learn with 2 stroke engines. Most builders are going off stuff that was developed 20 years ago and that is what they're giving the average consumer.

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