Bought a 2002.. errr 2004 RM 125 and now i need help!

Spagina

Spagina

PR Elite
So I wasnt planning on buying a 125 yet, but sometimes if i find a real good deal ill buy one, tear it to the frame and detail and fix any issues, then sell it for some more money. I found a "2002" rm 125 the other day for 800 - i got there, looked it over and could tell it had not been maintained very well, some kid had it, but it didnt have many hours on it. The footpegs, shifter, brake pedal, kicker, etc were all super tight and fresh. The chain and sprockets were stock, as was the front tire. I get the bike for $500... figure, no matter what i should be able to make some money off this....

I get home, and notice that it has Cr style front brake routing, and what i thought to be twin chamber forks - checked the vin, and yep its a 2004. Great, thats a better bike!

Here's the kicker - he said he bought it off his friend blown up and put a new top end in it (he showed me old piston, hole right through the top, no side scratches so i figured cylinder was good)... he also said he bought a new head. Well he thought the bike was a 2002, so im sure the head is for a 2002 on a 2004 cylinder... Did they change it enough that year that i need a new one?? It is in great shape, and i'm going to make sure its not warped before i put the bike back together.

So i tear the bike down to the frame to check everything out, and I check the numbers on the top of the piston - ITS FOR A 1999!!!! The bore of a 2004 is 53.95... the piston was 53.94!! Almost zero room for expansion... so as soon as i see this i check the cylinder... looks GREAT until i see that the chroming started to chip next to the power valve... GREAT. so now i dont know what to do, get it re chromed, bore and chrome, etc. I want to sell the bike after restoring but i do NOT sell junk. I frame the bikes i buy and make sure i would race it before i sell it... i believe in karma.
 
I have a 2004 that I sent to Eric Gorr and made a 144 out of it. Cost was $500 and he bored, ported and worked on exhaust valve. Runs great after rejetting, and the cost was about the same as rechroming a cylinder, porting and decking a head.
 
I think if I was planning on keeping it that is the route I would go. Since I'm flipping it i think I'm going to go with a new coating done by power seal.

My main question is what is the difference between the 2002-2004 heads? I know they changed the dome for performance, but is it
Still compatible enough to use? I don't want to have to spend an extra 140 if I don't have to
 
Check ebay for a cylinder. I got a 02 RM250 have been finding brand new ones for about $300, also they have a few places that do trade-ins for like $250, but Im not sure if it can be chipped though.

If you decide you dont want to fuss with it. I got a RMZ250, and RM250, and would love to have a RM125 to keep the yellow going in the garage.
 
Nah I can't sell it until its complete! The whole bike is in pieces on my work bench right now, when it goes back together it will be mint!
 
Spagina said:
Nah I can't sell it until its complete! The whole bike is in pieces on my work bench right now, when it goes back together it will be mint!
Click to expand...

I think you answered your own question... if it going to be "mint" then it does not matter if its compatible or not.. its wrong, so get the correct year head off ebay and go with it.

I have learned over the years that if you are going to buy old motocross bikes to re-build then you have to look at it as a Repo home in the ghetto. Assume everything is wrong and 99% of the time you will be correct. $500 my have been a tad high given that you have a "Frank-n-bike" Been there, done that. I bought a '79 Cr125 from "Crack head Kenny" that's the name I gave him since the thing was dirty, and "mostly" together, setting in his kitchen when I bought it. It had a '80 sleeve in the '79 cylinder, a completely different head (never figured out what it was from) and several other mystery parts. Needless to say, I got the correct parts and sold it as "restorable" and made a couple hundred bucks.

Well good luck, but remember, if your going for mint, get the correct parts.
 
Trust me i don't put stuff together half assed I just didn't know if they were compatible. I checked though and it's the same part number. So I'm good on the head.

Sending the cyl to powerseal USA - 179 for re chrome without welding needed. Ill be an extra 250 on the hole but the bike will be brand new inside so that's good.. I figure giving someone all the receipts will make them feel like it's a legit good bike
 
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