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196cc clone rebuild help..

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Dodgdatona

New member
I have a 196cc motor that ran fine with a mini 22mm carb, header before I took it apart last week.
I added a dyno cam billet rod, cl-4 clone cam, pvl billet flywheel, 18lb springs and I ported the head lightly. But now it will only fire up with a high rev and die after I blow air into one of the fuel vent lines(so it drops out of the carb).
I got the coil set to .038", valves to .003", flywheel key isn't sheered l, got spark(plug not flooded), and new unleaded gas.
And I know the cam is lined up on the dots.

Any ideas on what could be causing this?
 

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Dodgdatona said:
I have a 196cc motor that ran fine with a mini 22mm carb, header before I took it apart last week.
I added a dyno cam billet rod, cl-4 clone cam, pvl billet flywheel, 18lb springs and I protest the head lightly. But now it will only fire up with a high rev and die after I blow air into one of the fuel vent lines(so it drops out of the carb).
I got the coil set to .038", valves to .003", flywheel key isn't sheered l, got spark(plug not flooded), and new unleaded gas.
And I know the cam is lined up on the dots.

Any ideas on what could be causing this?
Click to expand...
Here's the cam install pic
 

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What size air jet and main jet are you using?

I have a similar motor on a genuine 22mm mikuni.......if it helps I found it only run properly with a 42.5 air jet......if I went above or below it ran like a dog......main jet started on a 120, but then worked down to a 100. Last dyno pull was 16.3hp and 8200rpm. Im on 95 octane pump gas.

I'm now pushing for 18-19hp around 9-9500rpm

The air jet size is critical. With all the mods you have made the fuelling characteristics change massively.

Also be sure you set the lash properly.
Set the inlet when the exhaust just starts to open
Set the exexhaust when the inlet just starts to close....... if not done properly you could have a valve hung open on the compression stroke 🧐
 
Knightly, where did you get your extra keys for your mikuni? Did your want to start like mine after I did all my work? And this may be a dump question, but where exactly is the air jet located at?
 
Lots of mods but the only fuel signal change was a little more valve duration. I'm not sure that would cause a no idle situation.
 
Dodgdatona said:
I have a 196cc motor that ran fine with a mini 22mm carb, header before I took it apart last week.
I added a dyno cam billet rod, cl-4 clone cam, pvl billet flywheel, 18lb springs and I ported the head lightly. But now it will only fire up with a high rev and die after I blow air into one of the fuel vent lines(so it drops out of the carb).
I got the coil set to .038", valves to .003", flywheel key isn't sheered l, got spark(plug not flooded), and new unleaded gas.
And I know the cam is lined up on the dots.

Any ideas on what could be causing this?
Click to expand...
It ran fine before you took it apart . Now it doesn't run fine .
You did something wrong .
 
Dodgdatona said:
Knightly, where did you get your extra keys for your mikuni? Did your want to start like mine after I did all my work? And this may be a dump question, but where exactly is the air jet located at?
Click to expand...
Just found the air and main jets on ebay. Im based in the UK but they are very common. To get at the air jet you need to take the float bowl cover off, then you can remove the air jet with a flat blade screwdriver. Its worth doing to find out exactly what you have to start with.

Also check the lash using the method I described.
 
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