eng tune probs

[dmckie]

took my Dirt Demon out today to tune it .26 eng everything is set to factory settings high needlle out 3 1/2 out low set to flush started just fine ran it 1/4 to 1/2 throttle to bring it up to temp before doing any adjustments bring it in at WOT to see ho it responds and it surges kind of like waaaa nn waaaa nn waaaa nn and get a nice puff of smoke each time it surges so i bring it in and it gopes from high idle to low in about 2 seconds so I'm thinking i need to lean the low end so i do about a 1/16 of a turn and take it back out and same thing .it dies and now wont start . take the plug out and its wet and glossy .so i wait 30 minutes and try again starts up runs for 1/2 tank and dies can't start it again it has done this same thing over and over i havent been able to tune it because of this problem .??????????????????????? oh yah, the temp was 230 and i do see a lot of air bubbles in the fuel line but i visualy checked everything and put new fule lines on and it all seams to be ok plus the surgeing seems to be pretty steady not random

 

[Robie6]

Sounds like ya still have an air leak homie. Bubbles in the fuel line is only 1 thing to check. Check the front bearing for leaks. Check the back plate for same & the carb seal, glow seal, shim seal. The low speed needle your talking about if your running the factory .26 is actually the mid-range needle adjustable seat if yours like mine has a 3 needle carb. The low speed needle is on the other side in the slide. Factory settings are 3 1/2 hsn, 3 1/2 mid range seat & 3 1/4 low speed. You'll have to re adjust to suit yourself but that'll get it running. Read up on 3-needle carbs to understand that mid range bugger. The mid range needle seat is usually set by seeing 1/3 of the seat showing as you look into the venturi or flush with the carb on the outside. The position of the seat has to do with when the venturi vacume passes over the seat drawing out the fuel. If not set far enough in the venturi the low speed needle will be completly out of the seat at about 1/4 throtle. If to far into the venturi the needle wont be completly out of the seat till near wot. Set the mid range flush with the carb & the low speed needle about 1/16 completly out of the seat at wot. Some damn thing like that, hope it works. I to have a dirt Demon. Expecting all four billet aluminum a-arms in the mail soon. You can email me with any problems ya may have with your D.D. I have had mine tore down several times now. Just like taking things apart-lol

 

[dmckie]

Well, robie6 did everything you suggested i did find that i had a screw loose on the back plate tightend it down and still the same thing. called hot bodies and he told me to send it in and they are going to send a repacement engine no questions asked (I thought that was pretty cool).My lhs isnt going to break this engine in .this time i am going to be able to do it .