Crapola RM...the saga continues....

[Micahdawg]

Ahite. I got my newly cnc'd head back from Eric Gorr in record time. He took some pretty significant material out of it and I now have a very noticable squish band (before it was almost non existant).

I slapped the top end together with a new Wiseco piston and immediately did a compression test. It was pulling 230 psi. Whoa. I chalked it up to all the oil that I caked in the cylinder during assembly and proceded to fire it up on FRESH 93 octane premix.

I will also note that I pulled my jetting back from 162/52 to 162/48. The bike fired up, sounded great...took it for a spin and it bucked around on the bottom, pulled good in the mid, felt flat on top.

I noticed that the bike was smoking pretty good...you could see very noticable trail of smoke streaming out the silencer throughout the entire range.

So I went home, drained the gas tank and threw in some fresh 99 octane premix. I wanted to make sure that the low end bucking was not detonation.

While the bike was sitting after my first ride, I noticed spooge dripping from the pipe/silencer connection. There was a nice trail going down the swingarm...along with speckling on the fender, caliper, etc...

I also removed the carb needle and set it from the 3rd position to the 2nd. Took the bike for a spin and it felt more responsive throughout the whole range, but still bucked around pretty good when you would let off the throttle. Anything from idle to 1/8th was making the bike buck around.

I finally closed my choke screw from 12 clicks out to just 4 clicks out. That seemed to help out and for the last few spins the bike did not buck. Air screw seemed happiest at 1.5-2 turns out.

I checked the spark plug after each ride and it never looked wet. I'm used to seeing a -little- evidence of oil on the plug...so it freaks me out to yank a totally dry plug. The color is uniformly grey/brown. It's not really grey, but it's not brown. Definitely not white though....so I don't know what to think.

Guess it's good enough to go riding with and I'll just keep an eye on the plug and keep tweaking the carb settings a little. Once I get the bike dialed in then I start reducing octane gradually to see if it will really run on 93.

Micah

 

[bikepilot]

I would suggest that you do another compression test to get an accurate figure. This will be a usefull baseline for future reference. If its still 230 you may want to consider adding a base gasket or something as that is quite high. I would call eric first though to get his thoughts.

good luck

josh

 

[Lissa]

Why is your RM crappola?

 

[Micahdawg]

Because it is requiring a lot of "de-screwing up" from previous owners not having a clue. And it's really challenging for me to get it in proper order without going over every friggen part to make sure its not screwed up.

The bike still isn't right. It's bucking on the low end and while I THINK it's a jetting issue, I don't know if it's lean or rich. So that makes it hard to adjust out if I don't even know where to start. Kinda like ramming my head against a wall.

Micah

 

[sick 96 250]

It just sounds like you need to dial in your jetting. Sometimes it can be a real pain in the A$$ but it happens. It took me almost 3 months to get my 96 Rm250 jetted correctly and what do i do, I sell it and now I have a 99 RM250 that needs to be jetted correctly again so the saga starts all over again. With all my RM's I have always had pretty good luck with the FMF tech specs for jetting. Eventhough it says 50/50 race fuel that always seems to get me the closest then i work my way from there. Normally just a few sizes up or down with have it figured out. Hope you get it dialed in so you can stop complaining :rotfl: Good Luck man :cool:

 

[Micahdawg]

Hope you get it dialed in so you can stop complaining

Ha ha...yeah, no shi+. FMF spec calls for 158 main, 48 pilot, 2nd clip. I'm at 162 main, 48 pilot, 2nd clip. The problems are down low so I don't see what going to a 158 would do for me....unless I'm dumping too much fuel in at 1/2 throttle and higher.....then when I slam the throttle slide shut it kinda chops due to excess fuel?

Looks like a WOT plug chop is in order.

Micah

 

[Lissa]

The price thats paid when purchasing used (hair loss and headaches?). :bang:

 

[sick 96 250]

If its down low its possible your pilot jet is off, try a 46 or 47 pilot and try a 49 or 50 pilot and see which direction it gets better, then you know where you need to fine tune it more in that direction. Keep us posted

Try a lower main while your at it and see what happens also. you'll have this solved in no time hopefully :laugh:

 

[ETS]

I really don't think it's your carb or jetting as long as everything is clean inside the carb. I played with the stock 48 pilot down do 42 and ran the 162 main jets. I've cut my slide and played with the air screw and all it did was affect throttle response and such. It would either run crisp or head the other way and burble at certain RPM's. It would never buck like your describing. No matter what I've done to my RM it still runs great, just sometimes cleaner than others. I think you have an ignition deal or possible engine leak through the crank seals. I've done similar to at least 10 different bikes I've owned over the years and minor jetting changes and such aren't going to make the bike unridable and ruin a powerband like yours is doing. Have you checked like someone else a while ago suggested to spray some starting fluid around the flywheel and intake to see if the engine races up?

 

[Micahdawg]

I have considered a crank leak, but if the crank leaked on the stator side shouldn't there be some evidence of oil behind the cover? I've had the cover off a couple times and it's totally dry inside.

I found the thread on that $17 DIY leakdown tester though and might give that a shot.

Micah

 

[ETS]

It could be leaking from the otherside so a leak down tester might be your new best friend.