Crf250f jetting being used on a modified apollo250rx

OBrienx · 07-23-2021, 04:52 AM

crf230f jetting suggested on a pwk30 carburetor and wondering if we could replicate these setting to a zong 250/233cc engine since theyre clones of the honda motor

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suggested crf230f tuning for a PWK30 30mm

132 main jet
middle clip on needle
45 pilot jet
2 turns out on screw
neutral/stock float adjustment(nothing touched)

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since the zong250cc engine is a replica of the crf230f engine and a few of us have done big bore and piston kits and cams on our bikes intended for a honda crf230f then why are we all running these low 115 main and 30 pilot jetted mikuni carburetors? cant we get better performance and less lean conditions running more close to a rich condition since its safer to do so?

Let me know what you thing ill leave updates below if anyone is interested in conversing about the topic. I know i was looking for info like this when my bike started to spudder and bog at high rpm higher gears and it turned out to be lean not a rich bog. i love pwk carb now theyre the goat 100% never using mikuni vm26's again.

*UPDATE*

Got it working using and very well also. i clocked my max speed at 116km/h but havent tried higher jets yet ran out of daylight but will tomorrow and post results (july 24 2021) and maybe some videos if anyone is real interested in seeing what a pwk can do for these bikes given your intake and everything is set and solid.

Main 115
pilot 35
#5 needle/slider clip (lean) (top slot)
1 1/2 turns of the air screw
93 octane gas

(612 above sea level) (15-72% humidity) (74deg f)

(Bike and mods are in my signature)

Notes:
-my compression would lower the amount of fuel needed so iv dropped the jet sizing from the recommended and 42 seemed like quite a jump from the 32 is was using but the 35 improved my ride so much no more hesitation bogs at throttle anymore it was very very fun and could finally walk wheelies with this carb installed. My 11:1 Wiseco on apollo vs the 9.0:1 CRF230f stock compression the suggestions are based off of are the reason i dropped the jetting down so much at first.

-didnt have a 120 main and still want to try it that on my todo and prob my best main jet to use but i have a 125 if this pilot jetting works well i might change my main to a 125 and see what happens.

-i know its hard to see a lean condition with unleaded gas but it wasnt rich at all and if anything it looked stoichmetric(slightly brown bu not white ish) but the ceramic below the electrode was still kind of white but also a new plug so wasnt sure how to read the plug here but i did notice my top end was somewhat blah and i didnt hear a loud bog yet so i assume im running lean still so im going to add more fuel to the tuning

ghostdancing · 09-13-2021, 01:01 PM

Impressive mods on your bike.. any piston deck height issues with the wiseco piston? Im also interested about your porting job..

OBrienx · 10-01-2021, 10:41 PM

piston kit changed piston throw, head height a bit, and the combustion head pattern to a better design..no deck clearance issues not sure if theres a kit people are using that change that a lot i used a honda kit

ghostdancing · 10-02-2021, 03:48 PM

what i would like to know is the following: i know that the honda 230 motor comes stock with the piston down in the hole a bit at TDC (lower compression), while the zong clone (zs169FMM) has the piston slight proud at TDC (honda static CR is around 8,6 while zong CR is around 9,0).. the chinese knock off is a slight warmed up honda motor.. my doubt is: if i use an athena big bore kit (67mm bore)i will have the piston deck height slight down in the hole, as in the original honda setup? (= not ideal)

07-23-2021, 04:52 AM	#1
OBrienx Join Date: Jul 2021 Location: London, Ontario, Canada Posts: 30	Crf250f jetting being used on a modified apollo250rx crf230f jetting suggested on a pwk30 carburetor and wondering if we could replicate these setting to a zong 250/233cc engine since theyre clones of the honda motor ---------------------- suggested crf230f tuning for a PWK30 30mm 132 main jet middle clip on needle 45 pilot jet 2 turns out on screw neutral/stock float adjustment(nothing touched) ----------------------------------------------- since the zong250cc engine is a replica of the crf230f engine and a few of us have done big bore and piston kits and cams on our bikes intended for a honda crf230f then why are we all running these low 115 main and 30 pilot jetted mikuni carburetors? cant we get better performance and less lean conditions running more close to a rich condition since its safer to do so? Let me know what you thing ill leave updates below if anyone is interested in conversing about the topic. I know i was looking for info like this when my bike started to spudder and bog at high rpm higher gears and it turned out to be lean not a rich bog. i love pwk carb now theyre the goat 100% never using mikuni vm26's again. UPDATE Got it working using and very well also. i clocked my max speed at 116km/h but havent tried higher jets yet ran out of daylight but will tomorrow and post results (july 24 2021) and maybe some videos if anyone is real interested in seeing what a pwk can do for these bikes given your intake and everything is set and solid. Main 115 pilot 35 #5 needle/slider clip (lean) (top slot) 1 1/2 turns of the air screw 93 octane gas (612 above sea level) (15-72% humidity) (74deg f) (Bike and mods are in my signature) Notes: -my compression would lower the amount of fuel needed so iv dropped the jet sizing from the recommended and 42 seemed like quite a jump from the 32 is was using but the 35 improved my ride so much no more hesitation bogs at throttle anymore it was very very fun and could finally walk wheelies with this carb installed. My 11:1 Wiseco on apollo vs the 9.0:1 CRF230f stock compression the suggestions are based off of are the reason i dropped the jetting down so much at first. -didnt have a 120 main and still want to try it that on my todo and prob my best main jet to use but i have a 125 if this pilot jetting works well i might change my main to a 125 and see what happens. -i know its hard to see a lean condition with unleaded gas but it wasnt rich at all and if anything it looked stoichmetric(slightly brown bu not white ish) but the ceramic below the electrode was still kind of white but also a new plug so wasnt sure how to read the plug here but i did notice my top end was somewhat blah and i didnt hear a loud bog yet so i assume im running lean still so im going to add more fuel to the tuning __________________ 2013 Apollo 250RX -Zong db36 233cc engine w/ titanium valves, ported exh. -WizeCo 11:1 piston -CRF230 Athena big bore cylinder -Powercore 788 Exhaust -HF K&N Pod Filter and intake -1/4 fuel lines and valves w/ plastic tank -HR handle bars and MX pully controls -CRF230 SHOWA fork -Oversized MX brakes & rotors -17T 46T (3.07 Gear ratio) JT Sprockets with a D.I.D gold MX chain -Keihin pwk30 30mm carburetor 115main/35pilot Last edited by OBrienx; 07-24-2021 at 06:42 AM.
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10-01-2021, 10:41 PM	#3
OBrienx Join Date: Jul 2021 Location: London, Ontario, Canada Posts: 30	piston kit changed piston throw, head height a bit, and the combustion head pattern to a better design..no deck clearance issues not sure if theres a kit people are using that change that a lot i used a honda kit __________________ 2013 Apollo 250RX -Zong db36 233cc engine w/ titanium valves, ported exh. -WizeCo 11:1 piston -CRF230 Athena big bore cylinder -Powercore 788 Exhaust -HF K&N Pod Filter and intake -1/4 fuel lines and valves w/ plastic tank -HR handle bars and MX pully controls -CRF230 SHOWA fork -Oversized MX brakes & rotors -17T 46T (3.07 Gear ratio) JT Sprockets with a D.I.D gold MX chain -Keihin pwk30 30mm carburetor 115main/35pilot
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09-13-2021, 01:01 PM	#2
ghostdancing Join Date: Jul 2021 Posts: 62	Impressive mods on your bike.. any piston deck height issues with the wiseco piston? Im also interested about your porting job..
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10-02-2021, 03:48 PM	#4
ghostdancing Join Date: Jul 2021 Posts: 62	what i would like to know is the following: i know that the honda 230 motor comes stock with the piston down in the hole a bit at TDC (lower compression), while the zong clone (zs169FMM) has the piston slight proud at TDC (honda static CR is around 8,6 while zong CR is around 9,0).. the chinese knock off is a slight warmed up honda motor.. my doubt is: if i use an athena big bore kit (67mm bore)i will have the piston deck height slight down in the hole, as in the original honda setup? (= not ideal)
	0