jetting help please

mrfubs · Aug 20, 2013

1 am running the cns carb and got my bike running great after rejetting. my problem is that i jetted and kind of tuned the carb when it was on break in fuel, i know i shouldnt have but i did. so now that im running 25:1 instead of 16:1 it wont hit the power band now. adjusting the idle air didnt do much.

i think i need go up on the main but im not sure?

Pablo · Aug 20, 2013

Well after a hard run and shut down with no idle or turn over, what does your plug look like?

I would say if you jetting for 16:1 oil and now you went to 25:1 I would say you are running fuel rich. (but it could be not related to air fuel!)

mrfubs · Aug 20, 2013

thanks pablo im new to tuning but ill take a pic of my plug and post it the plug looks perfect to me.. but doesnt run perfect. i also have 4 other jets ill try a smaller one tommarow!

Venice Motor Bikes · Aug 20, 2013

Depending on what kind of oil you're using?, I would use 32:1 & THEN re-jet it.

mrfubs · Aug 20, 2013

i went from using 16:1 Klots synthetic with 20% castor oil to 25:1 AMS oil Dominator Synthetic, 2 great lubercants

Venice Motor Bikes · Aug 20, 2013

I would switch to 50:1 if you're using full synthetic!! (seriously)

mrfubs · Aug 20, 2013

50:1 is way to risky on these rough engines cylinder plating would not last as long if you where to use a richer mix and still get optimal performance.

Pablo · Aug 20, 2013

HUh? I've run 50:1 in one engine for 5+ years now. Other junk has broken, internal lubed parts and cylinder/piston are fine. Depends on the lube!

Venice Motor Bikes · Aug 20, 2013

Read up on it here... There are guys here who've been using 100:1 for years in these little engines. (^)

(I wouldn't steer you wrong).

maniac57 · Aug 20, 2013

It's all about the quality of the lube.
The chinese use 16:1 because all they have for oil is bridge-of-the-nose skin grease.

mrfubs · Aug 20, 2013

i simply am amazed to hear that these engines have potential of running such a low mix and last that long, impressive!

mrfubs · Aug 21, 2013

Here is the plug now it looks perfect to me.

i did a few things, i raised the fuel level a little bit in the bowl i also drilled out the pilot jet a few sizes bigger and turned in the idle air all the way in and backed out 2 turns.

Bike hits power band faster and runs good!

Thanks for the help all.

mapbike · Aug 25, 2013

mrfubs said:
Here is the plug now it looks perfect to me.

i did a few things, i raised the fuel level a little bit in the bowl i also drilled out the pilot jet a few sizes bigger and turned in the idle air all the way in and backed out 2 turns.

Bike hits power band faster and runs good!

Thanks for the help all.

View attachment 62373

Just for fun and reading search 100:1 mix in the forum search option and be prepared for interesting opinions but most importantly the personal experience with 100:1 mix anda few more, these engines perform well on lean oil mixture as long as the right oil is used andthe carb is properly tuned.

Many have thousands of trouble free miles on Opti2 oil including myself.

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jetting help please

mrfubs

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Pablo

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Venice Motor Bikes

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Venice Motor Bikes

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Pablo

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Venice Motor Bikes

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maniac57

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