Can't get new motor to fire up

Ok I just added a jellow jacket head kit from HKmotos along with a full circle crank. I got the squish to .050 and added an IP2 pipe . After putting it all back together I can not get it to even sputter let alone run. The only carb mod I made during this was to drill thru the petcock. I had already bored and polished the carb prior to this and it was running fine, I also had it jetted correctly for the last mostly stock combo. It has a new fiberglass reed also. The spark seems strong also , nice and blue . I just can't seem to get it to catch and fire. It is not even close . It has a lot more compression than before and is harder to pull but i can still get it spinning pretty easily. Any ideas ? It is driving me nuts . I even took the carb apart and cleaned it again along with checking and resetting the gap to the coil.

Well sounds like it had to do with the petcock mod, but i'm no expert lol

I was thinking that also but it is not leaking past the float at all . The float seems to be able to hold back the extra fuel so i don't see how it could make a difference . Somebody correct me if I am wrong on my thinking . I am new to 2 strokes but not engines. I have worked with many different 4 strokes including many drag racing engines for more than 20 yrs. This little bugger has got me at the moment though . LOL

Take out the plug and check it to see if its wet or dry...

If its wet your coil may not have enough kick to ignite the mix under the higher squeeze and may need a stronger coil or the stock carb is so small and the engine so potent now the engine is drawing in more fuel to air ratio because of the increased velocity and pull of the new head kit.....youre most likely gonna have to go with a bigger carb with the same jetting as the stock carb to get it to fire without flooding the plug...

If the sparkplug is dry add fuel directly to the cylinder and see if you get a kick and the engine runs or sputters........... you need more fuel or theres an intake air leak somewhere.If not you may need to get a juicier coil....................Peace

Well my thought wasn't exactly that. I was thinking during the drilling of the petcock you could have somehow clogged up the fuel flow. Can you tell if fuel is flowing through?

Hows the plug look??

Cam beat me to it

hahh

You can also unsrew the drain plug on the bottom of the carb to see if your getting enough fuel. There should be a nice flow coming out of it.

did you mill your head to get that squish or did it come like that?

have the same headkit and it started up no problem but check the drain screw on the carb just to be positive your getting gas

Juanitoboy93 asked
(did you mill your head to get that squish or did it come like that? )

Yes, I did mill the cylinder to get that squish . Stock was .170 . There was fuel in the bowl but I have not checked to see if it flows well yet. I'll check that tonight or tomorrow am. The plug was completly dry so i'll start with that first and let you guys know . Thanks

Ok , checked to make sure fuel flow was good . The 1/4 tank I had emptied very quickly so I know the carb has fuel . I have the biggest jet that came in the jet pack from daves in the carb also. It is a .72 I believe. I double checked the gaskets and I don't believe I have an air leak anywhere . I'm still stumped. I may try ordering a dell rep 14 from daves . I want to make sure I am not overlooking anything easy also first. Cam , you mentioned a hotter coil ? Any idea where I can get that other than PBU ?

i would try a 68 instead
check for spark

Ok here's something you may of over looked. You may have the dome on crooked and it's leaking. When you put the dome on and the head you need to put the bolts in and only screw them down until they just touch the head. Than tighten each bolt a 1/4 turn each in a criss-cross pattern until they are tight. Kinda like you would tighten the lug nuts on a car tire. Than after you have riden it some recheck the bolts.

I wouldn't add a del rep unless you're ready for the stock jet size its .78 and the jet pack goes .80.85.90.95 hahh..
this site's actually goes lower: MT-A4/C-1 Water Cooled Pocket bike Carburetor Jet Pack (set of 6 jet).
but the price is iffy.. think I woulda rather gone with a real Dell'orto now that I need those.
cheers

Well I finally got it started . I used starting fluid and it fired right up and ran fine . Although I have no idle control at all and it idled very high. It seemed to run fine but after running the compression went from very high( hard to pull over) to very low (less hard than stock) . So I definatly have a problem someplace. StrayDawg63 said (You may have the dome on crooked and it's leaking.) I will have to check the crooked dome issue out as that would make sense on the starting and loss of compression after running. Thanks for all the input guys I really appreciate it. I'll keep plugging away till I figure it out . BTW my IP2 pipe I modded sounded great on the little quad. Way better than the stock piece of junk. I did also order a dell rep from daves just to try out .

i did the YJ BBK,petcock mod,CF reeds and .70 jet all at the same time and it fired up second pull and starts first pull every time now. but i did not set the squish maybe you took to much of the head. and check your crank seals mine were toast

did you center the crank in the case when you put it together so the bearings dont bind?

Ok , I checked the dome and it may have been off as one of the head bolts actually hit one of the screws that hold the case halves together. I shortened that bolt and ran a die down it and retapped the hole and it comes down evenly now .That definatly made for uneven torque on the head. Either my carb is toast or I still have an air leak somewhere though . It runs on the choke at very high RPM's , engaging the clutch high. With the choke off it sputters and dies. All the gaskets are good and in place. This thing is fighting me tooth and nail. Thanks for all the help so far guys .

Well get someone to hold on to the bike while it's started on the stand and check for a airleak by spraying some carb cleaner around the intake area but don't spray any in the airfilter and the seem between the 2 case halfs,the base of the cylinder and dome area. If the rev's change while spraying the carb cleaner around you found your airleak.