RMX 250 hard starting issues

[Sazooka 250]

Hey guys hows it going?

Recently bought myself a beautiful example of a 99 rmx250.

Upon buying this mean machine, i found it utterly impossible to start. Did some research and found that the stock PJ carburetor was a pile of poo, so i quickly purchased a short body PWK38 Airstriker with tps and solenoid.

With the new carb attached it starts after 4 kicks when cold with the choke on, when warm it will not start unless A) clutch start or B) let it cool down for about an hour. Jetting is #178 main #52 slow jet and the needle clip is 2nd from top. Sometimes when hot it will start with 1/8 throttle cracked, so im thinking maybe the pilot is too rich? Reeds are brand new as well pretty sure they are boyesen powerreeds.

Also did a compression test and it came back 150psi, upon pulling the top end there was some serious blow by on the piston, the bike has 9000kms on it leading me to believe its only been rebuilt once in its entire life.

Is my float level too high? too low? pilot jet? or compression?

Any help would be great guys!

[hybrid]

You could try playing with the idle screw to see if that helps.
Did you try the compression test when it's hot?

It's unusual to see hard starts when warm. It's normally the other way around.

[Sazooka 250]

Idle screw is at 2 turns out, any more and it runs on when closing the throttle at 80km/h and pulling the clutch in, plug is white/brownish on idle so the mixture seems ok. I know the main jet is way too big at 178.

Could never get it started to do a compression test when hot, and the only time i needed to restart was in the bush after having a break and it REALLY felt like the compression was way down, it would just slip straight past TDC, once it cooled it would be a little tighter and would eventually kick over after 5000 kicks. However hill start it would fire right up no worries at all and run like a champion, 1st and 2nd it pulled the front wheel up easily.

any more ideas? does the idle circuit seem ok? i have a feeling that the pilot is a bit rich?
Heres a photo of the piston

received_m_mid_1406543868145_56cf24171bb533be59_0.jpeg

(73.23 KiB) Downloaded 21 times

[hybrid]

You don't need to start it to do a compression test.
Take plugs out, screw in the tester and kick it a few times.

You need a tester that holds the pressure between kicks.
My 500 had pilots that were too big, but it didn't have trouble starting hot or cold. Just fouled plugs eventually. If your plugs look nice, it doesn't sound too rich.

[Sazooka 250]

Haha yeah, too many beers. never got a chance to test it while hot, but i can only assume it had less compression cause i could never get it to stick at TDC to kick it in the guts, it would get to TDC then just slide right past without much effort. when i did the cold test it took about 10 kicks to get it to 150psi. it bled off at about .5psi per minute.

I'm putting it back together next week when i finish the porting and chamber reshaping.

It was blowing a lot of oil out the rear silencer so i repacked with steel wool and cleaned the perforated tubing, had alot more midrange and bottom end after that but still blowing mass amounts of spooge out the tailpipe on full throttle, had to clean the plugs a couple times to hot start it, sometimes it took 4 kicks other times it took 45min to cool down then another 6000 kicks to start haha.

[hybrid]

You might need to take the pipe off and get rid of the oil. It will probably keep coming out after the rebuild if there is excess in the pipe. Some people seal the pipe and use caustic soda to clear it. Others throw it in a fire.

I'd say a fresh topend is going to go a long way to curing your starting issues.
I can't comment on your jet sizes though, as I'm not familiar with the bike/carb.