*Twin Cam CV Carb Rejet Suggestions

[black02flht]

From trial and error this is what I found works best.
I don't like to drill the slide and I shim (lift) the needle with 2-#4 washers for best results.

Glider,

Is it easier to pull the carb off or to raise the tank to gain access to the carb top? I pulled the carb off the intake but could not figure out how to remove the cables. So I put it back together again. ANy help would be greatly appreciated.

Thanks,

 

[glider.]

It can be done either way. If you look at the cables in the bracket on the carb and collapse the cable adjusters, it isn't hard to see how they come out.

 

[Melfunction]

Should I be seeing fuel coming out of the main around the needle at idle? I have a #190 main with the stock needle with a 0.037 washer under it. I'm wondering if it should be set lower to seat properly. It runs fine, but I noticed this today running in the garage with air cleaner off to check plunger movement. Plunger moved properly, but then I noticed the gas gushing up from the main at idle.

 

[fin_676]

Should I be seeing fuel coming out of the main around the needle at idle? I have a #190 main with the stock needle with a 0.037 washer under it. I'm wondering if it should be set lower to seat properly. It runs fine, but I noticed this today running in the garage with air cleaner off to check plunger movement. Plunger moved properly, but then I noticed the gas gushing up from the main at idle.

There is always fuel comming out all the jets all the time the air flowing through the carb causes a depression or suction in the throat of the carb sucking the fuel up through the jets
as the slide goes up it draws the needle up as the needle is taperd it allows more fuel to be drawn through the main jet as the air and suction increase

Brian

 

[BadBob]

Thanks for your reply. We did the two #4 washers and #46 idle jet. I also have SE II slip on mufflers. It is probably at about 2 3/4 turns out. When it is warmed up with enricher fully in, it pops when coming down a hill in 2nd doing about 30 mph. It also sometimes back fires. When I did 60 to 70 mph in 3rd gear and let off, it also back fires.
So what is the problem? Is it too rich? Should I back off the idle jet to 2 1/2 or less?

 

[glider.]

The SE II mufflers are great mufflers but a bit prone to popping on decel because of the low restriction.

The idle screw should be set as described above to the highest idle speed and nothing more to be properly set. Don't use it to lean out the mixture, the jetting is for that. The idle set screw is more for just the idle even thou it does extend up the fuel delivery range a bit.

 

[BadBob]

48 is too big, too much fuel in the low circuits. 46 would be the biggest I would go with 2 washers under the needle and warm it up a bit before riding.

We did the 46 jet and two washers. We started with 3 turns out on idle mixture screw. When riding on cold mornings, in the 40s, I still need enricher out a bit. So, we decided to fine tune. On the weekend, first we warmed up. We went back about 1 turn and it lost rpm. Then went forward 2 turns out is where we had the highest rpm. This is four turns out. Isn't this too far out? Do I need a larger idle jet, perhaps 48? Or should I leave it in the middle at 3 turns out and use the enricher on cold mornings? My concern about the using the 48 jet is that it will be too rich when warmer weather comes.

 

[glider.]

A 48 would be a bit big on a basically stock bike. Leave the 46 and adjust the idle mixture properly. The enricher use is common on a colder day until it warms up. Riding with it out after warmup may indicate an intake leak.

 

[BadBob]

I have SE IIs slip ons and K&N air filter. We installed #46 idle jet and two #4 washers under needle. It has 190 main jets which came on stock.

We do not have a vacuum leak. Rubber gasket around the carb is in excellent condition. We sprayed WD around this area with bike idling and there was no change in rpms.

Right now spark plug is medium gray in color even though been running with enricher out on cold mornings going to work. It does OK without enricher during the afternoons going home.

We adjusted idle jet with idle screw at about 1000 rpm. We had to turn it out FOUR turns to get best idle. You say #46 idle jet is largest we should go. So, should we leave adjustment of idle jet at 3 1/2 or 4 turns? Or should we go up to 48 idle jet?

 

[glider.]

You could try the 48 low jet but on most occasions it is too big. A larger than needed jet is going to give you a mushy response on the throttle at the bottom end and possibly surging as it advances through the different circuits in the carb. I'm still leaning towards a leak somewhere causing the problem.