Predator 670 carb help again!

[chazdo2]

I pulled the carb again float is working perfectly. It still gets gas in the intake flange by the choke butterflies all the time. There is a small hose right next to the gas inlet port on top of the carb. If I blow in it gas comes out the top by the butterflies if I put a vacuum on it the gas goes back in the carb. Is this hose suppose to be on some intake port somewhere? This looks like it might be my problem. Engine is running so rich plugs are black. Could removing the stock exhaust and running the two pipes into one then out the back into a next to nothing silencer cause some problems?

[slonomo]

Can you post a pic? It sounds like that might be your overflow/vent tube.

[chazdo2]

Yea Ill grab one in the morning1 The end of the tube is expanded like it fits over a fitting of some kind but I cant find it. Thanks you guys are the best!!!!

[chazdo2]

here they are its the one with the hemostats on it. Man they are handy for a lot of stuff I have a doctor buddy!!!!! I fix his stuff he fixes ME!!!! Its the smaller of the two coming out of the top of the carb.

[slonomo]

Yeah I think that's just a breather vent. Usually they just get routed to the intake somewhere or to a catch can. The carb has to have a vent so the liquid fuel inside the bowl is at a neutral atmosphere. Let me see if I can find a manual for that.

[slonomo]

Here's the manual, but it doesn't label that hose, so I just think it's either a vent tube or an overflow for if it gets tipped upside down.

https://manuals.harborfreight.com/ma...1999/61614.pdf

Your exhaust would not cause a rich condition. I'm thinking maybe you have dirt/debris in the pilot jet. You'll have to take the carb apart to clean that. It's common. The pilot jet is the smallest jet and it often gets plugged up. Change your fuel, drain it and flush out the lines, install new fuel filter. I don't like the plastic cheap China filters, I use a glass filter. I've had bad luck with the cheap filter coming apart inside those plastic ones. Don't let your fuel get too low in the tank, that's where all the debris is. Treat your fuel with Stabil with alcohol neutralizer.

[chazdo2]

Couple things first I have been reading your posts for years and not until yesterday did I dissect your screen name. That's funny as hell! Ok back to business I will pull the carb apart again but a plugged pilot jet would screw up the idle and mid range some I thought and on the lean side. Am I wrong? I will go through the fuel system again I must have missed something! I always treat the fuel because I go sometimes weeks without using it. As usual great advice from you guys! Ill get back to you soon see how I made out. Do you know what those jets under the sealed caps do? They are labeled " L " and " R " and I am assuming that means left and right side cylinder adjustments?
Thanks for the manual too! I couldnt find the one that came with my engine I know its the same one but cant find it!!!!

[slonomo]

Yep Slow No More

Pilot Screw:
If your pilot jet is located on the air side of the carb, its a pilot air jet. Adjusting it meters the amount of air allowed through the jet. Fully closed would raise the fuel to air ratio making it rich. So a plugged pilot air jet will run rich.

If the pilot screw is on the fuel side of the carb its a pilot fuel jet. Adusting it meters the amount of fuel passing through the jet. Fully closed it will allow no fuel making the mix lean. A plugged pilot fuel jet will run lean.

I'm not familiar with your carb, but those two screws are the pilot jet screws for each venturi. Since its a two barrel, there are two.

NP on the manual.

[chazdo2]

Thanks for the carb education didnt know that about the placement of the pilot jet I always interpreted one way thanks!!!!!

[chazdo2]

here are some pics. The pilot jets I believe are the ones with the " L " and " R " on the carb. They are the screw in spring loaded needles. I am a little confused if they are on the air side or the fuel side. I figure you guys can help. Also the main jet under the " R " is a 108 and the one under the " L " is a 105. Why and I hope thats right cause the first time I cleaned the carb I was assuming they were the same size so I may have mixed them up. The pilot jets are on the throttle side and not on the choke butterfly side.