Two Stroke Motocross

Two Stroke Motocross Forum => Technical => Topic started by: FredRandazzo on October 05, 2012, 04:00:51 PM

Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 05, 2012, 04:00:51 PM
Hey guys i just had one question today. My bike loves to run in fair weather, but when the wind picks up or its raining. My bike will not start .
Title: Rain and Wind problem(2000 RM 125)
Post by: arnego2 on October 05, 2012, 05:11:46 PM
First question: How old is the top end? Second: do you clean the carb regular?
Title: Rain and Wind problem(2000 RM 125)
Post by: riffraff on October 05, 2012, 05:44:00 PM
What trouble shooting have you done? I don't see how wind could affect anything
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 05, 2012, 08:39:23 PM
I just rebuilt the top end. In fair weather it will start up in one kick. In windy and rainy weather it will start but will only last for about 30 secs than shut down. And yes i do clean the carb regularly. i need to fix this before MX season starts. lol
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 05, 2012, 08:40:09 PM
Could it be that i have to big of jets and its shooting more gas in than it should
Title: Rain and Wind problem(2000 RM 125)
Post by: riffraff on October 05, 2012, 08:52:52 PM
I still don't understand how wind could affect it. Temp and humidity can but not that drastically. Does it die and then can be restarted? Have you checked for spark after it dies?
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 05, 2012, 09:11:46 PM
it does start after i bring it into a building. but when its outside with it being cold out and windy then it wont start or run.
Title: Rain and Wind problem(2000 RM 125)
Post by: riffraff on October 05, 2012, 09:53:49 PM
Forget the wind, it can't affect anything. The following was copied from a TSM article. Check for spark when it's cold.

The Weather Makes The Biggest Difference!
What are the conditions?The weather can have a profound affect on the carb jetting because of the changes in air density. When the air density increases, you will need to richen the air-fuel mixture to compensate. When the air density decreases, you will need to lean-out the air-fuel mixture leaner to compensate. Use the following as a guide to correcting your jetting when the weather changes:

Air temperature?when the air temperature increases, the air density becomes lower. This will make the air-fuel mixture richer. You must select jet sizes with a lower number to compensate for the lower air density. When the barometric pressure decreases, the opposite effect occurs.

Humidity?when the percentage of humidity in the air increases, the engine draws in a lower percentage of oxygen during each revolution because the water molecules (humidity) take the place of oxygen molecules in a given volume of air. High humidity will make the air-fuel mixture richer, so you should change to smaller jets.

 link to article --->     http://t.co/eryyiBvH
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 05, 2012, 10:12:37 PM
thx   :D
Title: Rain and Wind problem(2000 RM 125)
Post by: SachsGS on October 06, 2012, 04:57:20 PM
Check your electrical - connectors, kill button, everything.
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 06, 2012, 11:10:29 PM
thats not the prob. it has to be my jetting. i put a brand new plug into it today. It ran for a couple minutes then it bogged out and died
Title: Rain and Wind problem(2000 RM 125)
Post by: riffraff on October 06, 2012, 11:27:58 PM
Quote from: FredRandazzo on October 07, 2012, 06:10:29 AM
thats not the prob. it has to be my jetting. i put a brand new plug into it today. It ran for a couple minutes then it bogged out and died

What did the plug look like that you took out? When it ran for a couple minutes, was that at idle?
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 06, 2012, 11:34:38 PM
Um the plug was really black. And it was not at idle. I let it idle for a second and then it start to bog
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 12:00:34 AM
Does it smoke excessively and smell differently from a normal 2T exhaust? It almost sounds like you are burning up transmission fluid...
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 12:07:38 AM
It sounds like a 2 stroke. i just rebuilt the top end so
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 12:32:53 AM
Yeah, but the crank seals are in the bottom end and separate the transmission oil from the crank case where 2T oil and gas go into. When my seals went the bike would run for like 30 seconds and then stall because the plug would foul black. Sounds similar...
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 12:37:14 AM
Quote from: cnrcpla on October 07, 2012, 07:32:53 AM
Yeah, but the crank seals are in the bottom end and separate the transmission oil from the crank case where 2T oil and gas go into. When my seals went the bike would run for like 30 seconds and then stall because the plug would foul black. Sounds similar...

Ok but when its warmer out tho my bike will run no problem same as when im at the track. its only when its rainy and cold.
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 12:39:28 AM
hm... That is the only thing that doesn't sound like a crank seal. What are you running for a main jet? Sorry if you already answered that in a previous post.
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 12:41:00 AM
i didnt but i think that my jets are a little to big because to get it to not smoke i have to turn my air screw out 3 turns
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 12:45:25 AM
Your air screw only affects the engine for up to 1/3 throttle I believe, but that does make it sound like a jet issue, though I fail to see how the slight changes in weather affect it so drastically. What size are you running? Maybe try going down a few sized, jets are dirt cheap. Plug one in run it and plug chop (you are definitely jetted rich seeing as the plug is black). Take a day and nail the jetting with the air screw at stock setting (I think that should be 1 1/2 turns out). You should see a nice brown ish color on the plug when you get it right.
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 12:49:50 AM
Thanks i need to get this fixed before the start of mx season in 2013. lol Also my clutch is going out! Just thought id let u know.
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 12:54:00 AM
How can you tell the clutch is going? Slipping a lot? If you put the bike into 2nd and pin it and the bike accelerates smoothly, than the clutch should be fine. If it slips, than its not so good. Before buying another clutch, take the plates out and check to see if they are in spec. Some times a good cleaning or even a readjustment on the cable can fix a slipping clutch. How long do you go before changing the fluid?
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 12:56:29 AM
Well i think its going because when i put it in gear it the bike jumps and if i adjust it sometimes it doesnt fully disengage. and most of the time it doesnt fully engage. lol unless u think other wise
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 01:03:48 AM
I had the issue once, I ended up by cleaning all the plates, re soaking them in clean transmission fluid, and the putting them back in with some "clutch saver sx" fluid. Then I had to re-torque the springs and it was all set. The only way to tell if your clutch is worn for sure is to take the plates out and measure them with calipers and make sure they are within wear specs in the manual.
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 01:05:14 AM
Thanks another thing. Its hard to push when its in gear and the clutch is pulled in
Title: Rain and Wind problem(2000 RM 125)
Post by: cnrcpla on October 07, 2012, 01:09:39 AM
Mine wont roll freely with the clutch pulled in, its almost like the clutch isn't even engaged, but it will roll freely with the engine running. I have an after market clutch in, so its meant to be tight. But check the plates and if they are good than change the oil, clean and soak the plates, and torque the springs down to spec. Also, when adjusting the cable, you should have about 1/8 of free movement in the lever before it pulls the cable. Good luck and let us know how you make out with these fixes  :)
Title: Rain and Wind problem(2000 RM 125)
Post by: FredRandazzo on October 07, 2012, 01:11:04 AM
Thanks ill keep in touch  :D