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Missing at constant speed?

Jack Klarich said:
Made it worse? As in still popping? That should have fattened it up if it were lean? You sure you do not have an air leak?
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When I pulled the enrichener very slightly to try and fatten it, it gets worse. I realize that this is a fairly big shot of fuel but just trying to see if it makes it better or worse.

BUBBIE said:
Bodeen,

Sorry Your having Troubles with it working like I thought it would.:small3d023:

Is that carb Seated into the rubber gasket enough at the manifold?

signed....BUBBIE
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Checking manifold seal with some WD40 tonight when I get home. I went together very nicely and seemed to seal good but I will check it.
 
I know you are focused on the carb as the source of the problem but if I read your previous posts correctly, with the exception of the 48 slow jet, seems like the carb is set up fairly close. Checking for vacumm leak is a good idea. Could you have buggered the diaphragm in any way?

It has been my experience in these situations to return the carb to stock jetting and make one change at a time. Starting with the A/F idle screw, then the slow and then main/needle. IMHO, you are at that point. You know the float level is correct, so start with stock jetting. If you still have the popping with stock jetting, that is a good indicator that the problem lies elsewhere.

Does the popping exhibit on accel (under load), decel (no load) or at cruise (light load)?

Have you taken a plug reading? Changed plugs?
 
Checked for intake leak with WD40. No signs of a leak.

I am now back to where I started with the carb. Stock needle shimmed with two washers (the same washers). Newly adjusted float level, same high jet. The only thing different now is the 48 slow and I am going to play with the adjustment on this for a tank full or two.

Haven't taken a plug reading. Plugs are a couple weeks old. First thing I changed.

The symptom is light popping out the exhaust, like a miss under a light load at a constant RPM ie: second gear riding through the hood at a constant speed or going through a school zone. Under load runs great, decel seems fine too.
This isnt like the dreaded cough or loud popping that some experience.

I am going to run with this for a week. I will fo back with the 46 as my next move as I agree that with my setup a 48 should big FAT.

When I bought this bike, I went through all this because previous owner had dyno-super-kitted the stock carb and ran just awful. With the fuel mileage of a trash truck. So I meticulously went through and extracted the Dyno garbage and got it right. This is not a new practice for me to be sure.
 
I have to ask again have you played with the idle mixture screw yet? Or did I miss this
 
Have you done a compression check? A low cylinder will give you that slight miss at a constant rpm, but you wont feel the loss of power when you twist the throttle until it becomes a large uneven compression between the cylinders.
 
Bodeen said:
Oh yeah, Idle mixture screw is being played with.
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Where is the A/F idle screw setting? Have you removed the screw from the carb? Are you sure the o-ring wasn't lost if/when you removed the screw? Did you set the screw on a cold or hot motor? If I were in your situation, I know I am not, I would set the idle screw where the motor is "happy", never mind how many turns that requires but is should be between 2 and 4 and I would replace the 48 slow with the 46 and start from there.

Missing as you describe sounds like a lean condition but it could also indicate a rich condition where unspent fuel is burning off in the exhaust system. It would be interesting to see how the motor reacted to removing one or both of the washers.:newsmile09:
 
Compression check is a good idea!

Idle screw setting is currently at 2 turns is a "happy motor". O-ring (packing) is still intact. Adjustments on hot motor only. I've tried with and without washers and they have no effect on the condition.
 
Bodeen said:
Compression check is a good idea!

Idle screw setting is currently at 2 turns is a "happy motor". O-ring (packing) is still intact. Adjustments on hot motor only. I've tried with and without washers and they have no effect on the condition.
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Almost ready to believe the problem is not carb related but not ready to throw in the towel yet. The problem you describe indicates to me that the needle is in play; the straight section of the needle should be controlling fuel flow as exhibited by the fact that removing washers had no effect. Have you pulled the emulsion tube? Is the tube the Dynojet tube or the OEM tube. You might want to pull the tube and make sure all the orifices are open or if the tube is the Dynojet tube, replace it with the OEM tube.

The emulsion tube is where the raw fuel and air are "emulsified" before entering the intake. The Dynojet tube has much fewer holes than the OEM tube. Worth checking out.:D
 
dolt said:
Almost ready to believe the problem is not carb related but not ready to throw in the towel yet. The problem you describe indicates to me that the needle is in play; the straight section of the needle should be controlling fuel flow as exhibited by the fact that removing washers had no effect. Have you pulled the emulsion tube? Is the tube the Dynojet tube or the OEM tube. You might want to pull the tube and make sure all the orifices are open or if the tube is the Dynojet tube, replace it with the OEM tube.

The emulsion tube is where the raw fuel and air are "emulsified" before entering the intake. The Dynojet tube has much fewer holes than the OEM tube. Worth checking out.:D
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I'll put it on the list of the next thing to check.
 
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