Gas smell in oil

I'll give it a try

 

I have a Colortune also and my experience is not successful either.
Starting at 2-1/2 and tweaking 1/4 turn each way until it responds nicely has been my method. I haven’t given up yet with the Colortune, just need a rainy day with nothing to do.

 

Set them back to 2 1/2 turns out. Synced again. I did 3&4 not much change. Did 1&2 started to race, so I turned back the idle screw so it idled at 2000. Did 2&3 and it raced again but also surged and bogged down the surged again. I did the propane torch to see if there were vacuum leaks and no change. When I flip the throttle it takes forever to come back down.

 

Sound like it may be pulling fuel from main circuit.. Are the slides hanging?... and their bore silky smooth?

 

I'm pretty sure they are good and clean. I don't think they are hanging. I'll check again tomorrow. I'm almost tempted to pull everything apart one more time, but I really don't want to.

 

Well you said propane test passed, so its either pulling main circuit fuel, or carb pulling internal air leak past main circuit...etc

Start and idle it, throttle slightly so diaphragms activate, and visuall watch the slides, they should drop fairly quick once throttle flys close.

 

I think I should pull them off one more time and hit them again with some 1000 and WD 40

 

No!... Polish the bore's with #0000 steel wool. Not grit paper. the paper removes material, where as wool will polish. also make sure the main needle jet in bowl is pulling and seating the washer and emulsion tubes tight.

A seep in this area can cause even idle level vacuum to suck fuel.

And note the 2 1/2 to 2 3/4 turns is an estimated starting point, you can even start at 1 3/4 to 2 turns, just keep mental note of each carb adjusters position. And your end position may not all be exactly the same on each, but should aim for them to be.

Me (personally) I turn them in tighter (less) increments than 1/4 or 1/2 turns.
I treat them like the seconds marks on the clock not the minutes marks as most seem to do.

 

Steel wool and WD 40 or just by itself?

 

Make sure its #0000 steel wool, and use mothers, or any other aluminum polish.. Use finger to apply verry little to surface (light coating) all the way around bore, and then polish with wool. then clean rag to wipe clean each time. Repeat as necessary

Make sure whatever amount of polish used does not get into any ports etc...
Also keep carb bodies upside down while using the wool, as the fibers will break down, and could clog into carb holes etc...

Slides may not be your issue, but can eliminate it as a possible cause afterwards. Helping you narrow down the actual issue.

 

Not sure what you mean when you say " also make sure the main needle jet in bowl is pulling and seating the washer and emulsion tubes tight."

 

I'm coming into this thread late... Not sure of your bike and carb model, but in the bottom of the carb base inside the bowl. You have your two brass jets.

The center largest one is for main circuit fuel delivery and is controlled by the needle on your slides, you know the long needle on the end of them when u had them out?

Throttle controls the carb fly's, metering the amount of vacuum the engine is producing, thorough the carb venturi. when throttle is. closed and up to to 1/3rd of the way open the controlled vacuum is fairly low and carb uses (idle) jet for fuel and is limited by your top air adjusting screws for the idle jet and air mixture (ones u been adjusting).

As you keep rolling on the throttle vacuum level increases, the (main) jet circuit takes over, the diaphragms in top actuates and pulls that center needle away from the hole in main brass jet, into the exit of the carb (part that you mount into the rubber intake boots) while mixing with the air passing thorough the carb opening and into cylinder.

The part the needle feeds into when closing (letting off throttle) is brass and removable and called (emulsion tube)..... when the main jet in bowl area is removed. The main jet will have a brass washer with it. The jet, when tightened pulls the the emulsion tube towards it sealing top side of It, and washer seals the tube at the bottom, as main jet sits submerged in the fuel in bowl.

(now to my point..lol). If the tube is not sealed after main jet being tightened the engine vacuum can suck fuel straight out of the bowl.
Imagine you put a straw in a soda can and suck...... Same principal if emulsion tube is not sealed.

 

My bike is a 1982 xj650 Maxim that had been sitting since 1994. Original Hitachi carbs. This is my last piece to complete. Did the gas tank, the brakes, fork seals, and many other little things over the last two years. So frustrating, because I just wanna ride! Lol. I get at it tomorrow.

 

Ok, I have no hands on experience with the Hitachi carb rack, but the general theory and operation I described will still apply if they have (CV) rubber diaphragms on top side.

 

I'm sure the top hats have no cracks or rips and are fine, but I'll check them again also.

 

Took the carbs out again. There was gas in the boots that hold them in place. Took the steel wool to them and they do slide much better. Changed the oil again. A bite to eat and try running it again.

 

Had one more quick check. Do I have the pilot and main Jets reversed?

 

FYI - Those are the air jets you're looking at there. The fuel jets are located inside the float bowl.

 

I used the wrong term, but if they are backwards would that cause more vacuum to draw gas to the cylinders?

 

? hard to tell, those are the air jets and their backwards