I know this subject has been beat to death but I need help with 30mm Mikuni carbs on my cl350. I know basically how the jetting should be done. Short history: got the carbs jetted like this: needle jet 159P5, jet needle 6F5 clip in center slot, slide 2.5, main jet 135, secondary jet 27.5, air jet 2.0. Bike is stock bore, electronic ign, cl pipes with shorty open mufflers, pod filters. When I put the carbs on, the bike would not run on main jet. Jetted up in steps to 180 mains and now is a little rich on top end but running pretty well, however it is missing and running lousy right off idle to about 1/3 throttle. I have raised the needle and changed the secondary jets in steps all the way up to 40's and still runs lousy (cutting out and spitting). I don't know what else to do except changing the needle jet and needle, but I don't have cubic dollars to throw at this project and would appreciate any advice.
Geezergen
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did you do a compression test? You can't make the carbs work if the pistons and valves don't want to play, compression test is the quickest easiest way to see if things are behaving as they should inside the motor.
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does it still have points ignition? "cutting out and spitting" sounds spark related. Points and condenser are highly suspect if the firing is hit and miss.
... trust you already realize CV carbs and pod filters is a poor combination with vacuum operated carbs. No mention of year model so I assume you have CV carbs as most do.
Good battery is also very important on a battery/coil ignition, others here might chime in on that.
Spark plugs, ignition wires and plug cap, all good? I've bought brand new plugs in packs of 2 where 1 was DOA, crack in a plug insulator can sometimes result in the spark intermittently happening up inside instead of at the gap, that will also make the bike sputter and fart like crazy. Water in fuel also produces similar symptoms.
... trust you already realize CV carbs and pod filters is a poor combination with vacuum operated carbs. No mention of year model so I assume you have CV carbs as most do.
Good battery is also very important on a battery/coil ignition, others here might chime in on that.
Spark plugs, ignition wires and plug cap, all good? I've bought brand new plugs in packs of 2 where 1 was DOA, crack in a plug insulator can sometimes result in the spark intermittently happening up inside instead of at the gap, that will also make the bike sputter and fart like crazy. Water in fuel also produces similar symptoms.
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Rule out all those things and you might simply be experiencing CV carb combined with shorty open muffler & pod filter syndrome.
Did it run well with the stock air box and an exhaust system that has some reasonable back pressure in place, or was that ever an option?
Did it run well with the stock air box and an exhaust system that has some reasonable back pressure in place, or was that ever an option?
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In very general terms, VM is good, CV can get evil without an air box ymmv.
? maybe a problem in one of the float bowls ? if fuel level is off the venturi effect don't work so great.
... that would do the same symptoms you described.
? fuel level too high maybe, on Some carbs you can accidentally install floats upside down and it's a bitch to spot that.
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... if it was ignition timing related and everything seems perfect I'd retard the ignition to make it work better at low speed, advance it for wot.
But thats usually just a performance rule of thumb thing, not really a trouble-shoot :|
Just throwing it out there, possibly you already tried all these things.
But thats usually just a performance rule of thumb thing, not really a trouble-shoot :|
Just throwing it out there, possibly you already tried all these things.
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show him your video
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Pamco says: "You must use 5 ohm resistor type spark plug caps or resistor type plugs (not both)" ... whats the resistance between your coil and plug now?
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then just drop the main jet needle by one notch,
changing the jet size will affect a change throughout the whole operating range, changing the needle position changes only the 1/2 to wot operation.
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