carb issues

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Sep 3, 2009 | 10:00 PM

#11

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

Quote:

Originally Posted by ironsport83

i took the tank off today and cleaned all the junk out of it.The tank filter was full of crud but the inline filter was fairly clean,i think this might solve the problem.I put a bunch of pennies in the tank and dumped about a half a quart of wd 40 in the empty tank and sloshed it all around,it cleaned the tank out great all the nasty stuff is gone.After i cleaned the carb(wasnt dirty at all) and repositioned the acc pump jet twards the center of the manifold,the only thing i noticed was the jet was pushing all the fuel at once in like 1/8 of a turn is that to much and not enough past 1/8 throttle?

In my experience repositioning the acc pump is a mistake. When aimed at the center of the intake mani virtually all of the fuel goes to the front cylinder, none goes to the rear. When i tried this my front plug was very very dark from being way too rich, while the rear plug was too light. Repositioned the jet and it was ok again. IMO the guys who wrote the HotXL mag article got it wrong.

You should not run both an in-tank filter and an inline filter. Two filters in sequence slow down the flow of fuel too much causing lean problems. If the tank is genuinely clean you do not need an external filter.

In my experience the only way to clean up a rusty old tank is to use either the RedKote or the POR product. Otherwise the rust comes back.

The acc pump is working correctly. It gives a shot of fuel at the beginning of quick throttle openings to mix with the sudden rush of air when the throttle plate opens.

Sep 3, 2009 | 10:05 PM

#12

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

Here is a schematic i drew up, calling on my immense artistic skills and imagination, to illustrate the fuel flow with the acc pump jet aimed as original. The box represents the venturi. The blue lines represent the air flow. The red line represents the fuel flow from the acc pump. Note that the fuel will be evenly split between front and rear. If you re-aim the fuel to the middle none is carried by the air flow to the rear. None! Not a single drop!!

Sep 4, 2009 | 06:50 AM

#13

ironsport83

Thread Starter

5th Gear

Joined: Sep 2009

Posts: 9

Likes: 0

i didnt think it would improve anything,i noticed it looks like i can move the spring on this accel pump,would changing this position of this spring change when the accel pump starts coming on?

Sep 4, 2009 | 05:16 PM

#14

IronMick

Stellar HDF Member

Joined: Jun 2008

Posts: 3,179

Likes: 118

From: London, ON Canada

Quote:

Originally Posted by ironsport83

i didnt think it would improve anything,i noticed it looks like i can move the spring on this accel pump,would changing this position of this spring change when the accel pump starts coming on?

You are referring i think to the "fast idle" setting on the front side of the carb, operated by a screw similar to the normal idle screw which is on the back side. This should be set up so that the engine idles at 1500 RPM when fully warmed up, and with the choke pulled out to the first stop [about 1/2"]. This information is in the Factory Service Manual.

Having this set correctly does affect performance. I do not understand how, just that in my limited experience it can have a dramatic effect.

Sep 4, 2009 | 07:08 PM

#15

ironsport83

Thread Starter

5th Gear

Joined: Sep 2009

Posts: 9

Likes: 0

i figured it out,its the d*** throttle cable,i fooled witht his thing all week trying to get it to run right,after messing with it today i tried getting it to run and unhooked the cable it solved the problem.The cable is full of what looks like mud and grit and binding up the cable.Man do i feel stupid lol,i tore the carb apart cleaned it and all that,cleaned out all the tank and filters,changed the battery went through 3 sets of plugs and it was just a throttle cable lol.

thanks mick!