Two Stroke Motocross
Two Stroke Motocross Forum => General Two Stroke Talk => Topic started by: eprovenzano on June 29, 2017, 08:09:20 AM
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New Project... Barn fresh 04 RM 125.. My son's girlfriend mentioned to him I know where there's a bike that's been sitting for years (6 years to be exact). Ex boyfriend's... she called his step mother, it doesn't run... she said please come get it out of the barn, please, you can have it... FREE...
Adam picks it up, said the tires were 3 inches down in the dirt, wheels didn't want to turn. Was told by the ex that it has a full aftermarket exhaust, bored 40 over.... Adam didn't care, just wanted to collect the bikes and its parts and get out of there...
(http://i18.photobucket.com/albums/b125/eprovenzano/RM%20125%20barn%20fresh.jpg) (http://s18.photobucket.com/user/eprovenzano/media/RM%20125%20barn%20fresh.jpg.html)
So we gave it a much needed bath... found its missing a few small things, but its pretty complete. As usual I don't take believe what previous owners say they've done to their bikes.. After a quick inspection I see it has the stock exhaust... so I know the PO is full of shit... Before wasting my time I check for spark, yep, got lots of spark. So with that, let the tear down begin (the other RM in the pic below is his buddies, just happens to be a 04 RM 125 too)
(http://i18.photobucket.com/albums/b125/eprovenzano/rm%20125%20tear%20down.jpg) (http://s18.photobucket.com/user/eprovenzano/media/rm%20125%20tear%20down.jpg.html)
I drain the rads, it had engine ice in it... nice. Pull the head, so far good, measures out to a stock bore. I feel a slight scratch in the bore... hmmm I may be able to salvage this with just a top end refresh. I pull the cylinder... somethings not right. It takes me a while but then it hits me... someone resleeved the cylinder but didn't line it up... it's off 3/8 th's of an inch. How that hell do you do that... the ports are partially closed, including the power valve. It was blocked from being able to open...
(http://i18.photobucket.com/albums/b125/eprovenzano/RM%20cylinder.jpg) (http://s18.photobucket.com/user/eprovenzano/media/RM%20cylinder.jpg.html)
I'm dumbfounded as to how stupid some backyard mechanics are... When I 1st saw the sleeve didn't line up with the casting, I assumed the sleeve or casting was broke... nope.... upon closer inspection, it's just bad work... The crank is tight, no play in the big end bearing, and no play on the clutch or flywheel side...
So we'll have the sleeve replaced and of course put in a new top end. The bottom end will get washed out with clean diesel fuel. It needs a new chain and sprockets, levers, grips, and the rear fender stitched back together . Clutch plates are serviceable for now. It will make a fun track bike.
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Nice. Anytime I got a bike for free it ended up being more to get running than if I just bought one already running lol.
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I had one of those for 6 or 7 years. It was a good solid reliable bike.
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gonna be good thread epro
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I keep looking at that sleeve and wondering how anyone thought that was acceptable. It's just baffling.
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Coop I keep looking a it and keep laughing... how could no see something was off... when I first saw it I thought the sleeve was broken... even a dumbass back woods mechanic like me can see that's wrong... wow the mechanical skills of whoever put this together make me cringe.
I need to pull the power valve and look for any damage. If it tried to open, it would be hitting the sleeve.
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I'm going to bet it went something like this:
Cylinder hot -- Check!, sleeve cold -- Check! Now I'll just drop this in here and align it.... Crap, its stuck! Now what? Uh.... Maybe they won't notice!
LOL
--Ron.
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Where's the LIKE button... ;D ;D ;D ;D ;D
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I pulled the power valve... luckily its not damaged... :o...
so at this point, the sleeve gets replaced, new piston / ring and we're good to go.
Now my question... should I just go ahead and go with a 134 kit? If I do does the Power Valve need to be adjusted?
Nevermind... ;D I researched the requirements, and yes the power needs to be adjusted. I'll keep it at the stock bore...
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I do believe this is a fast 125 motor so stock should be good enough. I have heard and experienced numerous horror stories about tuning and reliability of the 134-144 big bores.
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Racer X I agree... I only considered it as a new sleeve is required... but I do prefer stock... plus parts are readily available. If my son decides to flip it, I'll rest easier knowing it was built to the factory specs.
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Quick pic of the power valve prior to disassembly. I pulled the power valve and all is in working order... Other then needing a good cleaning, all is good so far... oh and you got to love the lack of a gasket used on the power valve cover...
(http://i18.photobucket.com/albums/b125/eprovenzano/RM%20125%20Power%20Valve.jpg) (http://s18.photobucket.com/user/eprovenzano/media/RM%20125%20Power%20Valve.jpg.html)
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... oh and you got to love the lack of a gasket used on the power valve cover...
I am surprised it wasn't smeared up with red silicone.
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They are really good motors. Probably the best thing on the bike.
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My son and I was taking inventory of whats needed to put the bike back together. We noticed the rear wheel was difficult to spin... a missing wheel spacer may be the cause...
Parts list so far
New sleeve, piston and ring.
Air filter
Right rear wheel spacer
Front brake lever
Handle bars
Grips
Rear Sprocket
Rear Fender
Rear tire
Kill switch
Gas Cap
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Sorry for the lack of updates... My son is a recent grad from community college with a degree in Welding Technology. Since graduating in the spring, he found a job as a low level welder. He's been keeping himself busy with work, and trying to pay his bills and save up some cash for the bikes parts. ;D. He was struggling a little financially, (1st job didn't pay much, but he likes the work) so this was put onto the back burner... But he just got a call from his welding instructor... "I need for you to get here and apply for a position". He did and now he's just been hired... his hourly pay rate will increase by 88%... yes, 88%... I am one happy dad... maybe now he will move out of my basement, take his toys (bikes, jeeps) with him....
I may actually get my garage back... ;D
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In an effort to move out of dad's basements... my son decided he really needed the cash vs. an extra bike. He listed the RM and was able to sell it rather quickly. The new owner was happy to see where we dismantled the engine and other vital bits so he could see the condition of the engine. He was also happy to see the all parts were bagged and tagged... Where we could, all fasteners were put back where they came from... that's my standard rule... if possible put the nuts and bolts back where they came from... less chance of something coming up missing...
Sad to see the bike go, but happy to know that it's going to someone who will get it going again, and also my son will put the money towards the required deposits to rent a little house... he preferred to rent something with a basement so he can wrench on his bike during his down time...
YES DREAMS DO COME TRUE... He may actually move out some day.... ;D