250 The 1999 YZ250
- Thread starter Trfsrfr
- Start date
I am down with a stronger heavier steel sprocket, and I certainly dont mind the extra weight at this point.
It runs like crap right now, but is already way fast for me.
I've even considered installing a 3-wheeler thumb-type throttle just to keep myself from losing control. But I must say that going back to the XR200 after riding this is near impossible.
Good times.
It runs like crap right now, but is already way fast for me.
I've even considered installing a 3-wheeler thumb-type throttle just to keep myself from losing control. But I must say that going back to the XR200 after riding this is near impossible.
Good times.
Like the time I gave up my WR YZ250 for my daughters CRF230. She wanted to ride the 2 stroke so I let her. Couldn't get her off my bike even after lunch and beers. 
Thanks for the link Mike. I picked up 2 sprockets, 2 qts Yamalube 2R that Palmer recommended, about 7 different jets, a 5 gallon fuel jug, and some gloves for $110.00 with free 3-day shipping. Be here Thursday.
About the jetting - wouldn't it make sense for me to raise the needle up a notch and go run it, just to gauge whether or not I'm going in the right direction? That alone would fatten up the mix in the throttle range I am working in, would it not?
make sure the bike is sufficiently warmed while doing your test runs, cold two strokes run like shit. once you get it warmed up, if it still is going flat on overev lay it on its side for a bit while running to make sure the bowl is full up, than take another pass. If it screams on top but then goes back to usual, you have found your problem. Try it once or twice for good measure.
Went to the FMF website and they recommend a 50 pilot and a 178 main jet, so I took out the 172 and put in a 178.
I left the 50 pilot jet in.
Gas is a mix of 2 gallons 100 low lead and 3 gallons 91 premium mixed at 32:1 w Yamalube.
Went for a ride yesterday and did another plug chop. One side of the insulator has a darker spot near the tip, and when I look deeper into the plug, there is an even darker spot or line underneath that spot. Unfortunately I cant get a decent photo of it, and since I'm colorblind I cant tell you what color it is.
Below is a photo of the spark plug after yesterdays ride.
This is the plug chop with a 172 main jet.
I left the 50 pilot jet in.
Gas is a mix of 2 gallons 100 low lead and 3 gallons 91 premium mixed at 32:1 w Yamalube.
Went for a ride yesterday and did another plug chop. One side of the insulator has a darker spot near the tip, and when I look deeper into the plug, there is an even darker spot or line underneath that spot. Unfortunately I cant get a decent photo of it, and since I'm colorblind I cant tell you what color it is.
Below is a photo of the spark plug after yesterdays ride.
This is the plug chop with a 172 main jet.
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Says it is still rich to me. If i was worried about it being a crankshaft seal I would kind of backburner that thought. usually when i see that the plug is wet. Yours is over fueling or so low on compression that it looks like it is over fueling. If it wasnt missing I would probably tell you to leave it for now, since a little bit of chicken on the side of the jetting, especially during the time of year that the temp can drop further is not a bad idea.
I have a Bausch & Lomb lighted Lenscope, and I wish I had a way to take a pic of a spark plug through it.
I swapped out the 178 main jet for the 170 I have trying to be conservative, and took it around the block at my place twice (asphalt residential neighborhood, so couldn't get too crazy with it), and pulled it into my garage and gave it some revs.
I am not sure it was entirely hot cuz I didn't want to risk getting a ticket...
The brand new plug is totally different than the one I cut open, seen above. It's no longer grey and ashy.
The insulator is more like a mocha chocolate brown, with a darker wet looking ring around the top of it and has some silver speckles on it, and the center ground electrode looks like it has accumulated some silvery build-up on it.
Here is a pic;
I swapped out the 178 main jet for the 170 I have trying to be conservative, and took it around the block at my place twice (asphalt residential neighborhood, so couldn't get too crazy with it), and pulled it into my garage and gave it some revs.
I am not sure it was entirely hot cuz I didn't want to risk getting a ticket...
The brand new plug is totally different than the one I cut open, seen above. It's no longer grey and ashy.
The insulator is more like a mocha chocolate brown, with a darker wet looking ring around the top of it and has some silver speckles on it, and the center ground electrode looks like it has accumulated some silvery build-up on it.
Here is a pic;