1978 Liquifire carb adjustments

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tester007
Posts: 4
Joined: Fri Mar 01, 2024 3:36 pm
Real Name: Andre Sinclair

1978 Liquifire carb adjustments

Post by tester007 »

So I'm close to the end of this 'running sled I bought. Complete engine rebuild bottom up, new clutch (outer sheave on this was cracked)..etc. its been a ton of work and parts. I fired it up for the first time since tearing it down today and it sounds sweet, although sad all this work has wasted the last bit of snow we had, that I bought this for to take advantage of with my son.. but I digress...

I rebuilt the carbs, and noticed they were barely opening and closing. I sprayed some dry lube in the lines and feathered the throttle for a while and it really started to work well. I read in the manual that for serial 80,000 and up, the adjustment is to tape the throttle lever down to handle, then adjust the nut at the top until the slide is flush with the inner intake tube. So I start to do that and the adjustment bolt on the top falls out at max height..( It looks like original setting (have no clue if it was factory or was messed with) was about half extension of the adjustment bolt..), and the slide is still a half inch away from the top of the orifice top. I screwed it back down so there was some thread there to tighten the set bolt onto.. but now I have no clue what the correct 'wide open' height should be.. Shouldn't it be the intake completely clear of any of the slide blocking airflow?
harleysportster
Posts: 2965
Joined: Thu Jul 14, 2005 12:00 am
Real Name: Pat Scott
Location: Southeast Pa.

Re: 1978 Liquifire carb adjustments

Post by harleysportster »

I have the same sled an am able to set the carbs as per the Service Msnual. It sounds to me like the throttle cable had been changed sometime in the past and an incorrect cable has been installed.
'76 440 cyclone
'76 440 liquifire
'78 440 Cyclone
'75 JDX8 (sold to a member here)
'78 Liquifire(CrossCountry Clone)
'80 Liquifire(sold)
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JDGuy
Posts: 501
Joined: Fri Jul 22, 2005 12:00 am
Real Name: Guy
Location: SE Michigan

Re: 1978 Liquifire carb adjustments

Post by JDGuy »

If the lock nut at the carburetor has been overtighten it can brake the cable thread off leaving an inadequate amount to get the correct adjustment. That may have happened in your sleds past life? If you can get the correct adjustment on one carb, compare the thread lengths.
tester007
Posts: 4
Joined: Fri Mar 01, 2024 3:36 pm
Real Name: Andre Sinclair

Re: 1978 Liquifire carb adjustments

Post by tester007 »

Turns out the metal sleeve where the line breaks into 2 for the dual carbs was sliding up the cable and destroying the plastic sleeve. It looks like the plastic coating is all that holds this in place. I forced it back down and clamped in place just to see if adjustment now worked and it did. So I ordered a new cable.
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