The center hole is for the jet needle. Will that change after break-in? The bike started first kick and idled beatifully stone cold, even down at about 600rpm, right from jump street. Don't read the plugs until the fine tuning has been done and then make sure you use new plugs. I'm going to print it out and read through it. The Service Manual will provide valuable information on repairs and maintenance of your bike. Remember Bernoulli's effect in the venturi? These parts are needed for reassembly of the carburetor.
I don't have a degree finder to make a proper stand. I think I'll go ahead with the switch-back to the Keihin 38mm that I've got and see what happens. Some links below to a good magazine article old Easyriders? Mark where the adapter should be permanently aligned on the carb so that the carburetor is horizontally level. I rode it to work tonight. I'll try that, but I just can't seem to get a good idle no matter what I do. The accelerator pump is the gizmo at the right in this pic.
Did you get the Harley or did he make you ride the ricer? I am having the same trouble with mine, cutting out occasionally at the lights but the motor is still so tight - only about 200 miles on new pistons - I am not spending much time worrying about it. I am trying to find somewhere locally I can buy a 0. So as the throttle opens from idle, more gas is allowed in to match the extra air flowing in. I've had no problem with mine so far. Hi guys, I am reading this thread and the posted articles on adjusting our carbs and it mentions plugging the small hole on the accelerator passage. That's why I'm prepping my 'known good' Keihin butterfly for Ironhead duty.
Then I found a 1. The jet hole is in line with the lefthand edge of the pencil, but you get the general idea. This is the best this bike has ever run with this carb on it. I checked the original jet with a thread gauge and it had 28tpi. I think I've got a 165 main in there, I kind of like the sound and feel on the highway.
And then I can ease it out to. Mine was about that, hard to measure because the end is not square, but was still sticking out beyond the carb body at idle and pushing on the diaphragm. I do not agree with what the article says about aiming the pump. The accelerator pump jet should spray thru about the middle of the cutout when the choke plate is fully open. More of a lameness than a real misfire, no backfiring or farting, just kind of weak firing compared with the front jug. Seems the 1976-78 models with the 38mm carb like to have about an 88 slow jet and 175 main. Or gas will leak out there instead of getting squirted into your engine where it will do you some good.
The Keihin has a better metering cuircuit. So you can reduce the amount with the screw. I would guess that the pilot screw is set incorrectly, either too rich or too lean. Luckily he's got highway bars, so much fairing and and floorboards, so it stopped when those hit the ground, no noticeable damage to the bike. . Is there a point at which a Keihin carby needs throwing away or can they always be got to work again.
This was a trick I saw on YouTube, it works. Its all about the keihin 27029-88 carb. Here is what it took: 1. The float level is the first thing that needs to be checked when tuning your carb. Assembly Tricks for the diaphragm The diaphragm is easily mis-aligned or pinched. I wonder how accurately the needle enters the jet, seeing as it's mounted in the bottom of the float bowl. Screw in the new main jet and replace the float bowl.
Each time the piston goes up and down, two of the four strokes , one revolution has occurred. It's another factor to consider if you replace your carb. Make sure this hole is a clean straight hole. The flange is flat with no o-ring groove 3. This made it real hard to start and idled rough. I don't know which model you have. A lot of times they will be recessed inside of the two holes on the intake side lower portion of the carburetor.