Jetting a TM24 on a GT186.

[Pepot]

Hi people! I'm on the run in process of my new GT186 cylinder kit. I tried most of the jettings I've found in the carb section of this forum but I still have a little problem: When ridding at slow speed,at less than 1/3 of throttle the engine fourstrokes.It accelerates well and works fine past this point but is very annoying driving in slow traffic.
I matched the cylider to the cranckase,use a bigbore exaust,an italian LI 150 gearbox with a 16 teeth front sprocket and a BGM stator set at 19º BTDC.The plug is a B7ES.The filter box is been drilled and use a standard air filter.Having had a problem with a reed valve due to my old ignition I replaced the ignition and fit two reed petals on the boostport side to prevent it happens again following the advice of Richard Taylor.
I tried this ssettings :
ND H7 needle on second clip from top,185 main and 17,5 pilot. perfect spark plug colour,but fourstroking at first 1/3 throttle
5N14 needle 185 main and 17,5 pilot . Spark plug black and oily even on top clip and fourstroking anyhow...
4D H7 needle 186 main and 15 pilot . Haven't checked the plug but it keeps fourstroking at a1/3 throttle.
It's difficult to find anybody in Spain with this cylinder,so I hope to find any GT186 owner that can lend me a hand.
Thanks in andvance (hope you can understand my english...)
Greetings from the sunny Majorca!

[corrado]

Standard needle jet [atomiser] is a Q0, next leanest is P8, next richest is Q2. I'd try a P6, that should help lean it out below 1/2 throttle.

[Pepot]

Thanks for answering Corrado!Yes,you are right I'm using a Q0 atomiser. I'll try to find a P6 and try.
Thanks again!

[Pepot]

Just one more question:Do you think that having two reed petals in one side of the reed block can make setting the carb more difficult? I've been thinking of removing the reed block and leave it as standard before trying a different setting.
Now that I have a new ignition it makes no sense doubling the reed petals in the boost port side.I did this because one of the reed petals was pushed away into the reed block due to my old ignition when I tried the engine for the first time.

[The prisoner]

What are the news concerning your jetting problems?
TM24 is my second choice after 25 PHBL, mainly 'cause not a lot of feedback on it but Mikuni seems to be a very good carb option.

[Pepot]

Well prisoner,I had my Lammy tested by an old man who knows much more than me about 2 stroke engines and he said that maibe it wasn´t fourstroking due to a rich mixture ,but having problems due to a lack of fuel when the throttle is just a bit opened.In this conditions the engine sounds louder and misfires a little,so he suggested me not to ride the bike till I fit a bigger pilot jet. I'll let you know when I try the new 20 or 22.5 I´ve ordered.
When the throttle is just crack openned the engine sounds like a four stroke,but as my older and wiser friend made me notice it also misfires,shakes and sounds louder than in the middle range,where the engine sounds fine,so it could be a symptom of detonation due to a lean mixture.After having read the article about detonation in this forum I prefer not to risk and try a richer setting.
I went to a KTM service for some advice since some of their models fitted a TM24,and a tecnician told me that one of their 65cc bikes with a TM24 had a 22.5 pilot so a 17,5 was in his opinion very small for a 186cc...
Cheers from Majorca!!!