76 liquifire rev problem

Deleted User · Post by **Deleted User** » Sun Oct 16, 2005 8:53 pm

ok. i have a 76 liquifire 440 mounted in the rear of a home built off road go kart. finally got it running, but it seems to want to run at full throttle as soon as it starts. carbs are clean, but im not entirely sure if i have the fuel (IN) and the return fuel connected properly... the kart sat out on the farm for 2 years and was never touched other than by random farm animals... haha.

any help on this would be awesome, i wanna get this thing out and hurt myself ASAP.. i will also post pictures sometime soon as well....

also, i remember now. when u kill the motor, fuel just dumps out of the carbs till u turn the fuel valve off.... please, help!!!!!!

harleysportster · Post by **harleysportster** » Sun Oct 16, 2005 9:44 pm

The original style mikuni carbs do not have a return fuel line. The fuel inlet is a 1/4 inch O.D. fitting which receives the fuel line from the fuel pump.
It sounds like a throttle slide valve in one of the carbs is not installed correctly. The throttle slide valves have a groove cut in them length-wise, which fits over a pin installed in the carb sled bore. When installing the valves, the jet needle extending from the bottom of the slide valve must be fitted inside needle jet and then align the groove of the slide with the pin .
If fuel dumps out of the carbs when the engine is off, the needle/seats in the carbs need cleaned or replaced.

Deleted User · Post by **Deleted User** » Sun Oct 16, 2005 11:16 pm

the carbs are installed correctly. but now that u inform me of how they have no 'return' fuel line.... there are 2 fittings on each carb...well actually 3. 2 small ones for the 1/4 hose, and a single upright 'vent hole' i believe. but the 2 1/4 fittings are on each side of the carb, left and right... and on both carbs, i need to kno which to use to put fuel into...

so where does the unburnt fuel go from the carb? if there is no return??

also, like i mentioned the 2 1/4 fittings...maybe this thing is running full bore because i have both of them connected to the gas tank. due to me thinking one was a return fuel line... so maybe its actually sucking DOUBLE fuel into the carbs, causing it to run so fast? also, i pulled apart and cleaned the piss out of those carbs this morning, and made sure everything went back as it was.

so all i need to kno now is which inlet to use for the going in fuel....

400brian · Post by **400brian** » Mon Oct 17, 2005 12:55 am

Your Mikuni is a float regulated carb, no return line. One inlet, the rest are vents.

Deleted User · Post by **Deleted User** » Mon Oct 17, 2005 2:20 pm

ok, so which do i use for the fuel in then? or does it matter. when i had just the one fuel in hooked up, when the machine shut off, fuel pours out of those "vents" you speak of.

harleysportster · Post by **harleysportster** » Mon Oct 17, 2005 6:29 pm

The fuel inlet on each carb is a 1/4 inch barb fitting. The vent lines are small 1/8 inch fittings. The original color of the vent lines were a pinkish-red color. If gas is coming out the vents, the needle/seat is dirty or worn
and needs replaced.

400brian · Post by **400brian** » Mon Oct 17, 2005 6:30 pm

Sure it matters. My reccolection is the the inlet is for a 1/4" hose, the vents 1/8".
If you have it plumbed correctly, and it is overflowing, you have a float problem, or more likely a needle / seat that needs replacement.

If you have had this carb apart, you should have an idea of how it works. Are there two composite material floats in the bowl? Is the seat tight with a gasket under it?
With the carb body upside down, is the needle lever level? Look at the needle, does it have a groove in it? The last rebuild kit I bought, the new needle and seat weren't even close to being correct.

Deleted User · Post by **Deleted User** » Mon Oct 17, 2005 9:02 pm

ok, the carbs are plumbed correctly. i went to a local RV shop and they informed me for what to use. now. having said that. this thing still rev's out the roof upon starting, and only one cylinder is firing. i think that may be a bad coil, im getting it checked tomorrow. but , when the throttle is closed, should those slides be touching the bottom of the carb, or should there be a gap....(when lookin into the carb from intake side...)

so any help on this problem would be greatly appreciated.... thanks

harleysportster · Post by **harleysportster** » Mon Oct 17, 2005 9:27 pm

A small gap is normal, here is how to set the carbs.
Looking from the rear of the carb to the rubber mounting, there is a thumb screw with a slot in it for a screwdriver, which is the idle adjuster on the left side of the carb.
-Loosen the cables on both carbs at the top adjuster
-Loosen the idle adjuster and seat the throttle slide in the bottom of the carb
-Turn in the adjuster until a slight resistance is felt while placing a finger on the slide as the adjuster is turned.
-Turn the adjuster another 4 turns
-Set both carbs in the same manner
-hold the throttle lever against the handlebar with a rubber band or tape
-look inside the rear of both carbs and adjust the cables so the front bottom edge of the slide is flush with the top portion of the slide bore of the carb
-Set both carbs the same way.
-Remove rubber band or tape and see if throttle slides close to idle adjuster
The carbs are synchronized fairly close at this point but the idle speed could be off. Adjust both idle screws together to set idle

Deleted User · Post by **Deleted User** » Wed Oct 19, 2005 5:14 pm

ok, another problem just occured.... trying to access the points, in the magneato, and the magneto cover(?) will not come off the crank bolt.... ive busted 1 gear puller already, and do not want to bust another. is there some sort of trick/hint to getting these off? my old sled (76 ski-doo 440) wasnt nearly this hard to get off.... so is there a hidden clip or something??? ive tried heat, tried liquid wrench, and still nothing. one point is screwed i believe, so i need to see it.... any help???

harleysportster · Post by **harleysportster** » Wed Oct 19, 2005 10:07 pm

BRNYRD,
You need to remove the crank nut and washer on the end of the crank. Then using a steering wheel type puller( Y shape ) and high grade metric bolts( 6 mm ?) about 5 inches long, thread the bolts in the holes that are predrilled and taped in the flywheel. Tighten the puller and the flywheel should pop off. If after tightening and it does not pop off, rap the end the puller bolt with a hammer using a medium force and it should pop off.

400brian · Post by **400brian** » Thu Oct 20, 2005 12:49 am

Ahhh Harley, Wouldn't a '76 anything have a CDI box? Not that I know much about them, But wouldn't that have a bearing on what is going on here?
Can you lose just one side due to the Box? Or would that have to be a coil issue, I don't know, and my manual only goes to '74.

harleysportster · Post by **harleysportster** » Thu Oct 20, 2005 2:47 am

Brian,
You are correct, all '76 and up engines came with a cdi ignition. I am just going along with what he wanted to know, how to remove the flywheel. A few people have actually converted the cdi back to points. Anyway, if the engine has a cdi setup, the cdi box is mounted on the outside of the crankcase, behind the starter recoil . If you lost spark on one side, the first thing I would do is switch the external coils and see what happens. If you still don't have spark, the most common thing is the cdi box is bad. Check the coil swap and let us know and I will go farther into it.

400brian · Post by **400brian** » Thu Oct 20, 2005 2:13 pm

OK, but there must be a triggering device under the flywheel, am I correct?

I realize he wanted to know how to pull the flywheel, my question I guess, was if he even needed to. You pretty much answered that .

Deleted User · Post by **Deleted User** » Sat Oct 22, 2005 1:05 am

ok, update. got it running on two cylinders. now, the problem still occurs that it revs out the roof. WHY? can someone tell me how to reset those carbs, and start fresh? where things should be, how things should look.... thanks....