Strm Trpr

OP, read that article. You said yourself that you changed your ratio from 32:1 to 40:1 because your plugs looked black and wet, The oil in the pre-mix isn't what's making your plugs look that way, it's your jetting. Your motor was jetted too rich with 32:1 to begin with and now you've added more fuel by going to 40:1.

This is a good read. http://www.chronicmx.com/dirt-bike-tip-reduce-stroke-spooge/ OP, you might want to also make sure your idle is set correctly and that your carbs are sync'd at both idol and part throttle.

Maybe if he was jetted fat with his 32:1 and then switched to 40:1 that might be enough to need rejetting, but maybe not.It would be interesting to see if a 1/2 turn out on the airscrews and lowering the needle cleared it up though. I drop a pint of Yamalube 2R into my 5 gallon jug and that's that. No ratio rite needed. Been doing so for 20+yrs without a failure, knock wood...

On DMC's site, they call for 30 pilots and 280 mains with the airbox lid on. With no lid they suggest 320's. I agree, do the mods, leak down test the motor, if the leak down is good plug chop it.

Well, guess I'm wrong then.

Or you can try what I suggested with your airscrews and needle clip position to see if my theory about you changing your pre-mix is valid.

OK, let me try to explain this. 5 gallons of fuel is 640 ounces. 32:1 pre-mix you need to add 20 ounces of oil to 5 gallons of fuel. << 660 ounces of pre-mix. In a specific volume of 32:1 pre-mix you will have less parts per million of gasoline and more parts per million of oil. Now shoot 32:1 pre-mixed fuel thru your carb mixed with a fixed volume of air. The 32:1 pre-mixed fuel has less actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor. The air/fuel mixture has less fuel for a fixed volume of air and is now actually leaner. 40:1 pre-mix you need to add 16 ounces of oil to 5 gallons of fuel. << 656 ounces of pre-mix. In a specific volume of 40:1 pre-mix you will have more parts per million of gasoline and less parts per million of oil. Now shoot 40:1 pre-mixed fuel thru your carb mixed with a fixed volume of air. The 40:1 pre-mixed fuel has more actual combustible gasoline and is now mixing with a fixed volume of air flowing thru your carb into your motor. The air/fuel mixture has more fuel for a fixed volume of air and is now actually richer. Your motor is jetted for 32:1 pre-mix. Now you've now added more fuel to your pre-mix by pre-mixing 40:1. << more ppm of fuel to oil ppm. Your jets are too large and your motor is running rich and having a hard time getting on the pipe. Try this, turn your airscrews out 1/2 a turn and raise the clip on your needle up 1 groove and report back. By turning your airscrews out 1/2 a turn you've added more air to your idle circuit. By raising the clip up 1 groove you've actually lowered the needle into the needle jet and leaned out the mid-range. I bet it'll stay idling longer and it'll get on the pipe harder. I hope that makes sense...

Running your pre-mix 40:1 vs 32:1 is enough to require rejetting. Now the pre-mix has more fuel ppm and less oil ppm. The motor is now running richer even though your pre-mix is lean, fuel-oil ratio wise...

are you using fresh fuel, same fuel octane, same pre-mix oil and pre-mix ratio?

Pilot is dialed in when you can increase the idle a tiny bit by leaning/turning out the airscrews. But in order to see the tiny increase, (couple hundred rpm) you need a digital tach from eBay. Maybe add some fuel by raising the needle and putting the clip 1 groove below middle or 4th position. Then do a proper plug chop.

This link adds more info. http://myatvblog.com/how-to/atv-suspension-unleashed-easy-guide-precisely-setting-suspension/

Yup, hill shooters and drag racers want as much positive caster as possible for high speed straight line stability.

I used ^^^ same exact write up. I made a tool from 1" sq steel bar as long as the opposing faces of the knuckle are from one another. Drilled a hole on one end of the bar centered and about the same size as the hole in the knuckle where the ball joint seats. Then on the opposite side I drilled the same hole centered. I then fixtured the part held by the holes and faced all four sides parallel to the axis of the holes. With my Fireball LT a-arms mounted to the frame I inserted both ball joints into the holes and held them tight with a soft jawed clamp. Then I used a $30 digital angle finder from Harbor Freight to set caster. I set my caster at 6*. Be prepared to need a steering stabilizer if you go with 6* or less.

Ahh, that explains the 21cc domes and the leaner jets.And FWIW, DGL needles are richer than the CEL needles. That's got me thinking now. OP, how big of a pilot have you ran? Your main jet looks good. Try riding your bike with the chokes pulled on. If it comes on the pipe better than you need bigger pilots.

$1,500 shipped for the entire front suspension is a great deal. I paid $1495 shipped for just my LT Elka Stage 5's and I'm sooo glad I did!

Actually, those JD Performance Max Ground Clearance LT a-arms are pretty sick too. Check'em out here. http://www.jdperformance.net/488%20Web%20Design/a%20arms.html

Sweet!! Pismo is about 5.5hrs south for me. I'll be there the evening of July 5th thru the 9th. Have you seen these sick new Elka Stage 4's? http://bansheehq.com/forums/index.php?/topic/186556-elka-lt-jd-arms/#entry1808161 Might be a good deal if the eye to eye is 19" minimum for Fireball LT a-arms.

Bump for a sick set of shocks. Get the eye to eye measurement off your paperwork, might sell easier if stated.

I stand corrected.VP Racing C12 is not oxygenated but it is leaded.

Damn man, I wonder what your static compression w/21cc domes is?Looks like my suggestions above weren't very far off. What's your elevation?

is your idle set to around 1,500 rpms and are your 35's sync'd with a FAST sync tool? Airscrews must be equal as well. I start at 2 turns out. I use this to tune. http://m.ebay.com/itm/New-Digital-Tach-Hour-Meter-Tachometer-Gauge-For-2-Stroke-4-stroke-Gas-Engines-/331223584733?nav=SEARCH And this to sync. http://farmandsandtoys.com/ocart2/carburetor-sync-tool.html?search=Sync

Fixed it for a fellow DSM'r!!

Edit your post, remove that link and copy paste the "IMG" link.

Man, I can't stand chrome or polished anything on my bike. Brushed/natural Aluminum or 60% gloss powder is the only way I roll. However, I can't wait to see your ride!! Yeah, what motor you gonna run? And aren't you local, like ride Pismo on occasion?

Hell yeah it does!!