29cc cy engine mcd wont start fuel spraying onto air filter

[raykhan786]

hi all,
i have just replaced the piston and ring and gaskets etc on a 29cc cy engine that was previously a bit slow on the top end.

I have put the piston on the right way, the inlet manifold block holes are lined up, i have a very good spark, good compression, standard needle settings on a 688 carb and it just will not even fire! please help.

I have noticed lots of fuel has been spraying onto the airfilters and when i removed them the was a fair bit of fuel in the airfilter box, is that normal, whats happening their?

any help would be very appreciated, thanks

 

[46u]

Does it pop or hit at all? Did you have the flywheel off?

 

[raykhan786]

No i haven't had tge flywheel off. When i first replaced the puston i faced the arrow to the carb which did cause a clunking sound so i faced it the itger way and their is no noisebut it just will not start

 

[46u]

Week ago Sunday I heat cycled a tank through my 30.5 I put together and it took some doing to get it started but I got a tank through it. You did not say if you can get it to pop or hit at all. Does the plug get wet with fuel? Did you try putting the carb back to factory settings? Did you try a new plug? I have seen plugs that would fire when they where not under compression but would not fire under compression.

Before you did all this you did not have a problem starting it?

 

[whittron]

Pull the plug and pour a tiny bit of gas into the cylinder and try starting,mine did the same for some reason ounce it fired up it started to pull the gas from the carb,and ran fine just make sure you put the plug back in before starting lol.

 

[46u]

Pull the plug and pour a tiny bit of gas into the cylinder and try starting,mine did the same for some reason ounce it fired up it started to pull the gas from the carb,and ran fine just make sure you put the plug back in before starting lol.

MAX drop or two and small drops at that. Make sure you do not flood it. My concern is he is getting a lot of blow back in to the air filter.

 

[Timmahh]

im wondering if when you initially installed the piston backwords (mark on top toward intake) if the ring snagged the roof of the exhaust port.

 

[raykhan786]

okay an update then:.....btw thank you all for responses

Previously the engine started fine but i got the kit as the top end was really crap.

after ages of bad luck i decided to restrip the engine but as i did so i thought i would check the parts sent to me...well the piston was a 35 not a 36mm so instantly i though thats it. I swapped pistons back but put the new ring on as that is correct.
tried and tried but still no fire.
I was suspicious of it flooding si i disconnected the fuel, primed the bubble, took the plug out pulled the starter and then put the plug back in and pulled and we got a bit of a pop but obviously with very little fuel that wasnt going to do much so then i reconnected the fuel removed the airfilters, had the throttle fuly open and it finally started to fire!

This is really wierd, i am on normal fuel settings 1 1/2 H 1 1/4 L. anyways i have just been running it in for the new ring but im still feel that the top end is going to be slow judging by the first half of the throttle.

so to conclude:

engine starts when airfilters are removed and throttle is fully open
top end is still slow
anymore problems and its going in a ditch

any suggestions at this stage?

 

[raykhan786]

Also i have realised why the top end is slow. my gear ratio was something like 30/33 23/26. i had know idea about the gears! i have changed it to 33/30 23/26. i was tempted to do 26/23 aswell but i thought this may really killl the acceleration and possibly clutch??

is 33/30 23/26 a good set up, good top speed but not to slow off the line? do i need to buy other gears to improve my setup. I use it on fields and gravely roads if that has anything to do with it........?

thanks

 

[46u]

I just got done breaking in my 30.5 and factory settings where WAY RICH! After I got it break in and started tuning I had to go bellow what HPI recommends and still a little rich. But I ran a tank out like that and next time I run it I might lean it out a littler more.

Do not know about your gearing as all I have is a HPI 5b SS RIGHT NOW.