Reed valve problems

can anyone tell me why i have seem to have a fuel starvation problem on start up with my reed vavle setup.
i have to pour some petrol down the carb to get her to go, but when she starts it’s fine can run all day long.
everything sems to be ok everything bolted down, nice strong spark, just a problem starting.


ok you have a PWK I guess 28? (I think you made a mistake writing, it is a keihin not a mikuni ),
but , with which kit and exhaust and reed block and crank?

thanks guys, did have to strip one thing though, clutch fell apart on me!!! damm thing.[:’(]


you could start with:

Check your slow jet it is of correct size or not blocked

If you are sure it is not due to slow jet then check if you have a minor air leak. What kind of reed bloc you have? If it is a Malossi
go an check my net address below and see few prob. related to malossi reed block.

If doing this the problem is still there then ask again.
We have to proceed by esclusions if not it will take longer to solve your prob.

i noitced that as well on the block & filled it down, poss not enough so will take it back apart, i’ve got a mikuni PWK carb on same as in your pics what’s your set up jet wise?


check as beerace suggested your start choke meccanism.
You don’t have a starter jet to change so just check the meccanism works well.

for the keihin as starting try to ger this
main 135
slow 45
Needle JJG (clip 2nd position from top)
slide cut away 3.5

you know this will serve you as a guide so you should get some spare jets smaller or bigger to get it right.

yes are the same since both are keihin pattern (copy).

and if next time you tell me your set up I will be able to help you a little more.

yep got it wrong, keihin 28/30, standard crank, malossi 210 with reed block, sito race exhaust not sito plus.

Once youve put petrol down manifold does it tick over ok? If so the choke jet is incorrect or the cable isnt pulling it open enough. When checking for an air leak, use an oil can and squirt two stroke oil around suspected area. If air leak exist youll get a different running sound and plumes of smoke from the exhaust. No need to strip anything.

think i’ve may have found the problem, slow jet 38 & main 142.


now i haven’t really bothered to sort out the carb that’s what it came with so now i’ll get cracking.


after you change them let me know if you solved the prob.

check your plug with plug chop tech. to be sure about the142 main jet. For me it is too big but I don’t have your engine here so can’t say 100%, so check.
The 38 slow jet is too small for your engine. It will give you hard time starting in cold weather.
Put on either a 42 or a 45.

but you never said which set up you have.
I guessed was a Malossi 210…

scootrs only seem to have a max 40 slow jet, are the koso ones on the sip web site the same, as the moody keihin i have from scootrs.[?[]