Fuel question

Hey gang!

Okay as per my last thread carbs cleaned (church of clean ...clean), synched and ColorTuned pre YICs tool and post YICS tool...bike was running really nicely.

Added fuel and put premium in...now it seems as though once op temp is reached she is idling high.

Is it possible that because I synched and tuned with plain jane regular gas and switched that this could be the culprit?

Are these bikes even rated for the higher octane fuels?

Kinda wanna rule this in or out before I yank the carbs.

 

Don't yank the carbs, just turn the main idle knob down a hair.

I had the same problem when I went to CANADA...

As for the fuel choices, good old regular is supposed to be fine; but personally I'm sticking to premium.

 

Ah cool thanks as that is a huge relief!

 

nope...didn't work

 

Okay trying to wrap my head around this so maybe better brains/experience can help.

A few more details may help so for starters by "high idle" I mean in the 1800-2000 rpm range.

I tried BigFizs suggestion of adjusting the main idle but to no avail.

I then drained the tank of the Premium, replaced it with regular which helped marginally. Then I re-synched the carbs.

It has helped lower the op temp idle down to 14-1500 rpm.

Another thing I noticed after the Premium was that it was running hotter as well. Did a sniff of the oil and yep, fuel smell there. Checked the airbox but it was bone dry so....I guess it could still be residual gas smell as I have only changed the oil twice since the carb rebuild but I have sniff checked it a few times before the Premium and had not noticed the smell to be this strong. It does seem to have faded a bit since I replaced the Premium and seems to be running a little cooler again.

I'm gonna wait a bit before I touch anything else but thoughts/explanations would sure help me think y way through this.

 

What method did you use to set your float levels?

 

dry then wet to make sure, does this sound like a float level thing?

 

Could be, or an enrichment plungers not all shutting off fully thing, it was the smell of gas in the oil that made me suggest it.

 

Yeah I'm kind of leaning the same way unfortunately...

How would I determine if the enrichment valves aren't seating properly?

The floats i can (hopefully) handle ;-)

 

I have seen high idol problems before in the sync of the carbs. The carbs could be spot on. If it will not idle down with the screw they need to be re sync. First check the slack in the cable make sure its not whats holding it off the screw. I have seen people sync their carbs with the idle screw backed all the way out they just opened the butterflies to get the rpm right which will mess you up every time. I am not saying you did it that way but have seen it happen

 

hey it's worth checking for sure...anything that means I don't have to pull the rack LOL! ;-)

 

Check cable routing too, make sure your throttle cable isn't hanging up on anything.

Also, you **could** have a small air leak that get worse when it warms up. If the mixture is a little rich, and air can get to the engine without going through the carbs, then the engine speed picks up with the extra fuel/air mixture.

When you adjusted the idle, did you make small adjustments, when the bike is warmed up and level? You'll play with the idle forever if you try to set it on a cold engine.

 

yep all synch and colortune was done after engine was at op temp...

also checked for leaks via propane method

After riding around today a little bit it seems as though it is back to "normal"...idle staying down around where it should be so maybe it was just the premium after all...weird.

I'll let things go for a few days and see what develops, hopefully nothing ;-)

 

Well decided to go ahead and drain the oil last night and there was definitely gas in it...not nearly as much as when I had done it prior to carb clean/rebuild but it was there so....

I left the petcock in the ON position overnight with oil plug in (did not replace oil). Checked this morning and a slight amount of oil came out, about what one would expect as far as volume from draining down overnight. Did not seem to be any gas in it.

Right now it is sitting with petcock on Pri and I will check it in several hours.

IF I have gas at that point would my problem be floats, petcock or possibly both? I am figuring probably floats.

One thing that dawned on me while thinking last night was the one thing I did not clean was the float pin passage of the float itself...in other words the inside of the "loop" where the float pin passes thru the float arm. I didn't have anything readily available to scrub with and at that point was paranoid (as I am new to this) of damaging the float.

I'd guess 1 or more of the floats is sticking slightly.

BTW, all needle valves/assemblies are brand new.

 

I'm confused by your troubleshooting in regards to the petcock.

If the petcock is working correctly, in ON it shouldn't flow without a vacuum signal.

In PRI it's an open faucet.

If you're concerned about the petcock, disconnect the main fuel line, leave it in "ON" and put a clean piece of white paper under it, and leave it for an extended period. If it drips it will stain the paper.

 

Ah okay I misunderstood how it works...I thought it was the opposite.

So we should know now that it doesn't appear to be leaking vigorously as no gas appeared after sitting all night in ON position, correct?