Bringing this old thread back, problem still not fixed- new theory with knowledge thrown in from a friend with CV carb experience: Maybe its not the slide and its low float level?? He says no matter what position my thumb is at, the CV slide meters the fuel mix, so if it was sticking the engine would just act like im holding it at 1/4 throttle but still run perfect?? He said me spraying the sillicone on the slide just gave the bowl a few minutes to slowly fill, thus fooling me into thinking it actually did something?
Thoughts? Worth replacing the float seat and valve?

 

Yes...float levels can also be an issue...should be a casting mark to set the dry level at...

 

Extremely unlikely to be the float. Your friend is forgetting the stupid throttle position sensor, holding the throttle wide open and just getting 1/4 throttle is going to upset the CDI's calculations. Also a way higher vacuum, where the fuel enters the airstream, is going to alter things. SU's oil filled dashpot gave an "accelerator pump" effect by slowing the piston's rise. Honda did a quiet recall on 500 manual versions, as the cable routing dribbled rainwater onto the TPS, which then failed, could you have a TPS fault?

 

A TPS on a carb...interesting...

 

That's why I was never to fond of Hondas Keihin carbs when one would come in for service or carb problems.Plus on most of them the seat wasn't replaceable,just the float needle. Mikunis were so much easier to work on Same thing on my old Night Hawk.No tps but couldn't replace a seat. If the seat wears out you had to replace the blamed carb as my manual called for.

 

Wanted to update everyone, more so future google searches will display the fix than updating a multi year problem. I don't ride the Rubicon much, just sits so it was not in anyway a priority to fix But it was a bad iridium spark plug- I had pulled it and checked spark many times, and the color was a nice light grey so I didn't think it was a fault- but after my sons 2 smoke ATV fouled a plug, and ran kind of the same I swapped the plug and now it runs perfect. Little embarrassing to say the least but I wanted to close this up with a fix. Take care guys!

 

Glad you found the fault, and came back, so many post on here, then never post what the fault turned out to be. I regularly write on here about changing the plug first when a machine won't go or runs badly and the owner is convinced it is a carb problem. It may look OK, and spark, but if you replace it and it isn't the fault, you have only lost a couple of £ and should/would have replaced the plug at the next service anyway. I have had overcharging voltage regulators "cook" plugs, so it may be worth checking you are not getting over 14.5v at the battery when revving the engine.

 

yup, fooled a 43 year old gear head here. It was always in the back of my mind with the old saying, storage related failure is carb but if it fails running its electrical