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Do I need to jet or just make an adjustment?


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I am hoping that somenone can help me with this problem I am having with my 2001 RM 250. The bike is easy to start, usually fires up in 1 or 2 kicks. However, when riding it is kind of difficult to get into the power-band. In fact, when I am riding at a higher RPM and using around 1/2 or 3/4 throttle it typically will not get into the power band unless I quick clutch the bike. It is like pulling the clutch in and allowing the engine to rev freely cleans the oil off of the plug that is caused by a rich slow jet issue. After the plug is free of built up oil and I am running at 1/2 to full throttle the bike seems to run as it should. My plug appears to be a little rich but it is not too bad and there is a hint of the blackish tan color that it should be. I am thinking that 0 to 1/4 throttle is running rich and any throttle position above 1/4 throttle is jetted properly. I had the pipe off and the power valve appears to be operating correctly and is free of any excessive buildup. beyond this power issue. I have oil coming out of my silencer. I will attach pictures and the pictures were taken after about 4 hours of woods riding and hill climbing. Honestly, I have no idea how many hrs are on the bike. However, I would imagine that I should do a top end fairly soon. So my question is where should I start? If you think it is a jetting issue what adjustments should be made ie. float, needle jet, main jet, slow jet. As far as the oil coming out of the silencer I have no idea. I am using 80w Bel Ray Gear Saver and it is filled to specification. I am sure there is not too much in there.

http://www.facebook.com/#!/photo.php?pid=719096&id=1674907954&fbid=1311019630300

http://www.facebook.com/#!/photo.php?pid=719097&id=1674907954&fbid=1311019750303

http://www.facebook.com/#!/photo.php?pid=719098&id=1674907954&fbid=1311019790304

NOTE: I am currently Mixing my fuel at 36:1 and using Bel Ray MC-1 two stroke racing. Also, my air filter is new and oiled correctly.

Edited by anda1983
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You are jetted rich and that is the wrong oil for your purpose. Its not a bad oil just the wrong one for you right now.

Use a very Basic premix oil at 30:1 or 32:1 like Suzuki CCI. Very Good very cheap! next rebuild your topend, and repack your silencer. be sure to clean up the powervalves and ports. clean the carb and start the jetting process found here:

https://thumpertalk.com/forum/showthread.php?t=749204

here is the direct link: https://thumpertalk.com/forum/showthread.php?t=412662

Good luck

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Ok, as far as repacking my silencer... I just did that before my last ride which as 2 days before my post about jetting. Moreover, I just pulled my carb. and check my reeds. Everything looks good. I am running a 162 main and 48 pilot which is factory setting. However, at one point in time I had set the needle jet to the 2nd notch, therefore, I moved it back to the 3rd notch as it is factory settings. I am going to purchase the suzuki 2-stroke oil that you recommended and mix at 32:1 and see how it goes from there. Is this a good approach? As a side note my Air skrew was turned most of the way in. I now positioned it to 1 1/2 turns out (factory setting). The area I ride has around 800-1000 elevation. Average temp is around 70 degrees with around 70% humidity.

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Well the bike should have a good topend and you mentioned it was in need of a rebuild so I would do that 1st and then re jet. you can always do a compression test and see how good the PSI's are.... it should be about 190psi other than that its a good approach.

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I plan on doing the top end asap. But I am just home from college for the summer and broke as shit. So, I would imagine in the next week or 2 I can earn enough money to order the piston and gaskets. Beyond that, I would like to ride in the mean time. I haven't road the bike in about 3 years. Anyway, you had mentioned that I can do a compression check? I was unaware that a compression check can be accurately preformed on a 2-stroke. Are there any special steps needed to check the compression on the bike?

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(Thats a myth I hear..... open or close doesn't matter to me ! )

Thats a Fact not a myth, Try it both ways and see for yourself

let me correct my qoute.....

Thats a myth, so I hear

After over 30 years of building motors I might have learned something, but I guess not......

Some people crack the throttle, others don't. I prefer my readings via closed throttle roughly at an idle setting.

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