ok so i bought a 2000 rm 250 alil while back ...btw it was completely stock , topend and everything... well when im riding at 1/8 to 1/4 throttle and i pin it it will bog for a second and then pull right out to the topend just fine... so ive adjusted the air screw leaner and richer with no real affect on the bog... and played withthe needle clip postion an nothing seemed to help... well the longer i rode the bike i began to feel a surg but only when crusing at a low rpm again 1/8 to 1/4 throttle and it sounds like preigintion or detionation becuase everytime i hear the hammer hitting the cylinder sound it surgs forward alil... it doesnt do it much maybe once or twice every 10 seconds..... so i decided to tear down the engine to check for any damage to the piston and to just lookk around ... well i replace the topend(the piston showed no sides of detionation or anything..looked good) and the bottom end , water pump seal and bearngs so i could start fresh.. powervavle is clean , new gaskets everywhere and did a leak down test and everything is nice and tight and holds pressure..
i also went threw and cleaned the carb and so i could also check the jetting..

main jet- 155
pilot jet- 42
stock needle on the 3rd clip positon
choke clicker- 12 clicks out
1-1/2 turns out on the air screw

i run 93 with klotz technaplate at 40:1
air temp around 70-75
elevation is 768 FT.
the manual recommends 95 or higher octane... could this be my problem? cause both problems r back with the fresh motor...the only thing i changed was the reeds to boyeson dual stage power reeds...pipe silencer everthing is stock.... i do have some spooged running down my silencer but not much... so i figure im alil rich... ill get a pic of the plug today for ya all to see...

Check your PV solenoid, I am not talking about the powervalve. I am talking about the the little solenoid that is hooked to the top of the cylinder with the vacuum line running to it. They get premix in them and gum up and stop working. I am almost certin the  00 and 01 are the only years to have this solenoid and it gets over looked. I didn't know my had it until someone pointed it out to me.

jackson409 said:

ok what do i do to check forr proper operation?

i just rode the bike and it seems the knock sound is 1/4 throttle to maybe 1/2 while cruizing so im thinkin a needle adjustment is where im headed...and it seems as the richer i go on the air screw it gets harder to start and harder to make idle.... im confused with this darn new old bike...lol

My 02 and my 03 do the same thing. My wifes 01 seems to be perfect. I almost think this is just a trait of these motors(moto guys probably dont notice because they never ride below 1/4 throttle). I have tried all kinds of jetting, inspection,ect.... with no conclusive results. Next, I am gonna try a Scaryfast Co. powernow. It helped my KTM 300 so I figure it's 100bucks and hopefully it works, or I will still use it so I didnt completely waste 100 bucks.LOL! It is very hard for me to ride tech stuff with this boglike miss, but I am becoming more used to it and can plan my attack better after some time. As for octane, Euro and Jap bikes claim 95oct, but that is a euro scale which translates to about 91-92 octane here. I am also gonna try a hotter plug to see if it helps. I have tried race gas in full and 1/2 mix. Nothing seems to make it better. I am a bit dissapointed in Eric Gore since I sent him an Email explaining my issues and am willing to spend some cash if needed to fix it but he never replied. I figure he is probably the best to deal with this since all my local shops like PC and Bill's pipes dont know how to help me, they build high performance motor for moto which isnt what I need for offroad. Oh well, good luck and if I get any updates I will relay them here.

yea ive tried a richer pilot, needle clip changes, main jet changes...nothing helps...im stumped....

Check some of my other post,out of the 20 or so bikes i've owned the 00 RM250 has been the worst to get dialed in right.I finally got it though and now she goes the f-ing snot!!

dude help me.... im so stuck an dont wanna just thro my money away ...could the sound just be my pv closing an opening???

both the 42 pilot an 45 pilot seemed to both want the airscrew set at 1 1/2 turns open... i just get more smoke with the 45 than the 42... but power seems to be the same... i dont get it... this bike is weird!!! an ive jetted a few bikes but this one is just a plain biotch!

Im running a 152 main,38 pilot,needle at the very top clip(leantest) and air screw is roughly 1.75 out.I have a few mods and the temp here right now is  45 degress. Michigan temps and elevations are very close to Ontario temps.

I had to completly lean the sh*t out of this bike!! I been running at this setting all summer and just tweak the air screw when the temps change outside.

The only smoke I get is at start up otherwise I have ZERO smoke and my silencer is DRY inside. BTW the 38 pilot jet I got from a Honda dealer,Suzuki only had 45,40,35. I run the bike at 32:1 with Honda HP2 oil

jonnyukon said:

I am betting it is not your jetting I bet it is that solenoid and yes, check to see that is working. I don't know how much voltage is needed to work it but I am telling you without this functioning your bike will ping like crazy. This solenoid works the timing at half throttle and up and it will be way out of time if this isn't working.

jackson409 said:

ok right on.... i went back to my stock jetting 155, 42, 3rd clip , choke at 3 turns out which is 18 clicks, and 1 1/2 on the air screw which is what procircut sugguest and went back to 32:1 and mixed 110 octane and 93 half and half and almost all signs of the pinging sound were gone an it ran pretty good today..with just alil spooge on the tip so the engine temp def came up some..i cant touch the rads for more than a second..... so i def know im on the right track to somewhere.. now knowin that soleniod has an affect on timing.. thank u .. ill check it tomorrow for sure... but i still have the bogg... its anywhere from 3/8 -0 throttle... imma try an get some video tuesday of it doing it ... maybe its just my big ass boggin the bike ... i got 85lbs on the bike..lol

alright... it was froze up so i took it all apart an got it workin again.. imma put it back on an try it after the rtv i used to reseal the top rubber cap an wires back up is dry...

jonnyukon said:

good thing you didn't break it like my dumb ass did:bonk:. it cost 85 bucks:banghead:

jackson409 said:

dang... yea 78.53 is my cost on it ... how did u break it anyhow? lol the pindle on mine was stuck open...i just pb blasted it..let is soak an worked it out an cleaned it up an applied alil anti seize an she was good to go...or did u break the housing? i dont see how it affects timing...12 volts an the valve opens an it releases pressure i guess...

jonnyukon said:

I was trying to take it apart and broke the nipple off that the vacuum line attached to. It was done for after that. I could have got one off ebay for 40 but didn't want some other piece of crap that was gummed up.

I don't know how it works but my bike was pinging just a little and once I broke it and capped off the nipple on the cylinder it is way worse so I am sure mine was stuck open too. I ordered mine from here. Where did you get a price of 78 at?

local guy http://www.shspowersports.com/
yea mine was also pinging just alil bit.... sweet i hope this works

jonnyukon said:

Wow! my local guy wanted 104 for it. He is usually right on with Internet pricing but not on this. I always try to buy from him to keep the small guy in business but got to go where my wallet tells me to. Let us know how it turns out. I should be getting mine any day now. It shipped already so mail man needs to get his as$ in gear.

jackson409 said:

yea he is the cheapest so i got to ride for a second today .... the pinging is gone!!! but the bog is way worse now... and it was harder to start now today too.... took me 5 kicks when its usually one good one... today was 15-20 degrees cooler today then when i was workin on jettin it to but damn.... i can roll it on an its fine but if i just hammer on it the bog will dang near killl it...so maybe im still too rich... i got lotss of smoke...

jonnyukon said:

Okay, glad your ping is gone so I know that would defiantly fix my issue. I tried to go back and see where it is you are at now, but got confused. so where are you at now with the carb, needle pos, pilot, main, air screw, choke idle?? Do you have a fresh plug in it.