urgent. regarding rm 125

[obaja]

Hi i have a 2001 rm 125 and was wondering if anybody knew how to check the compression on it with a compression tester or if anyone knew what the stock compression should be? Thanks in advance.

[2005GZ250]

Just install the compression tester and kick the engine over until you get the higest reading on the gauge. My '73 GT750 3cyl 2-stroke makes about 120-130psi per cylinder with the engine cold and thats 250cc per cylinder. If you get a low reading add a few drops of oil to the cylinder and try again, and if the reading is still low then you may have worn rings or a head gasket problem. Post your results.

[nateW]

Originally Posted by 2005GZ250

Just install the compression tester and kick the engine over until you get the higest reading on the gauge. My '73 GT750 3cyl 2-stroke makes about 120-130psi per cylinder with the engine cold and thats 250cc per cylinder. If you get a low reading add a few drops of oil to the cylinder and try again, and if the reading is still low then you may have worn rings or a head gasket problem. Post your results.

You said that wrong. If you add oil and the reading comes up then you have bad rings. If the reading remains low then you have bad valve problems. Or a very big hole in a piston. lol

Also for a proper compression test, take out all the spark plugs to run the test.

[2005GZ250]

He has a single cylinder 2-stroke engine and there are no valves to worry about and when I tested my 3 cyl I did remove all the plugs.

[obaja]

Cool thanks a lot guys, now does anyone have the specs for a 2001 rm 125, what the compression should be in psi?

[2005GZ250]

I don't know the specs but what kind of problem do you have?

[obaja]

My problem is a lot of oil coming out of the pipe. I got the bike with a rebuilt engine including main bearings and piston and rod and everything. Rod about 8 times, 6 hours a piece. When i first got it it didnt put a drop of oil out for the first 3 rides, now its been constant. Starts and runs just like it did day one- perfect. Its got the fmf fatty and turbine core 2 with v force reeds. Have never had a problem starting or running this bike. and performance hasnt dropped at all. Also i have been using the exact same oil and oil mixture since day one,32:1 So why is all this oil comming out of the pipe?

[Robbie C]

It should read around 120 psi. If it starts within the first few kicks....usually means no need to check compression however. Check to make sure. When the bikes compression drops too low it will start getting harder to start and your saying it starts fine, so how much oil are you mixing with the gas ? 32:1 are you sure ? If you add too much, the bike will spit out oil from the pipe. Your tranny (GEAR) oil has no contact with combustion chamber...thats why you have to mix the gas with oil for 2 stroke engines. Buy a mixing funnel and measure the mix...the key is don't over/under the mix ratio. Refer to owners manual. This you probably already know....Try using a different 2 stroke oil. I use redline - it says you can mix as little as 100:1 but I mix a 25:1 with no problems. I also suggest (if it running good) get out there and giv'r sh*t and burn all that extra oil up in the pipe. Run it hard ! If you still seem to be having problems, drain all the gas and take off the pipe and clean it - refill tank, then your starting from scratch. If it still smokes bad or spits oil *you need to check with a dealer*.

[Rickster]

When was the last time you cleaned your air filter?

[obaja]

O trust me, i service my bike like crazy! I cleand the air filter 2 rides ago. No difference if i clean it or not, but i still clean it at the most 3 rides, say if i go for a short ride then i let it get to 3 rides. But the filter im always cleanin because thats like the heart of a 2 stroke- gotta have clean air goin in. Hmm

120psi??? wow, i got 174psi. for the compression test. But anyways i do have a "ratio rite" measuring cup and always measure exactly 32:1 in my gas. Maybe carb needs to be cleaned out or what? I have v force reeds, would that have something to do with this problem?

I have already repacked the exhaust btw, it even leaks out of the little conjunction to the rear silencer... hmmm

[the_privateer]

spooge means you're running rich. learn to read the plug. If its black and wet, you're too rich, if its white you're too lean. A brownish tanish color is perfect. when rejetting (do it yourself, its easier than you think and they way overcharge at any shop, just use the manual) go down one size at a time on the main jet and do a plug test after every change. for the pilot and needle jet, going by feel is the best way to decide adjustments.

btw 174psi is good, 120 would be ok for a bike made in the 70's but for a modern bike it'd be time for new rings

you should probably repack the silencer also

[obaja]

Originally Posted by the_privateer

spooge means you're running rich. learn to read the plug. If its black and wet, you're too rich, if its white you're too lean. A brownish tanish color is perfect. when rejetting (do it yourself, its easier than you think and they way overcharge at any shop, just use the manual) go down one size at a time on the main jet and do a plug test after every change. for the pilot and needle jet, going by feel is the best way to decide adjustments.

btw 174psi is good, 120 would be ok for a bike made in the 70's but for a modern bike it'd be time for new rings

you should probably repack the silencer also

Thanks a lot for the reply. I will re-read the manual on how to adjust it and take the carb off and re jett it. hmmmmm, ok ill give it a try. Thanks again

[the_privateer]

let us know how it turns out (I thought my bike ran good until i learned how to jet) and remember if its too rich you may foul some plugs-no big deal, but if its too lean you can seize it up, so check that plug often when making adjustments

while you're working on it, take the expansion chamber off and hang it vertically so all the oil can drip out, if theres carbon build up inside it you can drop a half dozen or so nuts in it, plug the ends and shake the %%%%% outta it and it will loosen that crap up so you can shake it out, just count how many nuts you put in and make sure you get 'em all out

I just noticed you said you already repacked the silencer, is this when it started spooging?, that would make sense because the 'glass was probably so saturated with oil that no more could get through and that is why it started spooging when you repacked it. not that it changes anything but just trying to figure out why it didn't spooge for the first few rides. spooge is a funny word

[obaja]

Originally Posted by the_privateer

I just noticed you said you already repacked the silencer, is this when it started spooging?, that would make sense because the 'glass was probably so saturated with oil that no more could get through and that is why it started spooging when you repacked it. not that it changes anything but just trying to figure out why it didn't spooge for the first few rides. spooge is a funny word

No it started spooging maybe after 3-4 rides after i bought it. Im so lost. After i changed the packing, there was no difference. wich is interesting. I would expect the packing to at least suck up oil untill it was full then start spooging again out the tail pipe but i did it right off the bat- if i remmeber correctly. O and wich way do i hang the expansion pipe upside down? With the big opening(end that comes of the head) to the top or bottom?

[the_privateer]

you could probably hang it either way, i did mine big end up

again the spooge has very little to do with the packing and everything to do with jetting