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Hif44 Struggling To Tune

Posted: Tue Apr 20, 2021 6:35 pm
by Zeemax_mini
Hi all,

Hoping someone can offer me some advice!

I've got a 1380 with a HIF44 fitted, the engine is fairly new but has just had a recon ported and flowed head fitted. It wasn't smoking before but now really is. The plugs and exhaust tip is black so I'm assuming it's running very rich, but the mixture screw doesn't seem to be doing much at all and if I lift the lifting pin slightly there's also no change (unless I pull it right up and the engine dies).

Anyone able to offer any wisdom?!

Cheers, dom

Re: Hif44 Struggling To Tune

Posted: Tue Apr 20, 2021 7:14 pm
by jay weinstein
Check the float level and needle and seat

Re: Hif44 Struggling To Tune

Posted: Tue Apr 20, 2021 7:29 pm
by bwaminispeed
Also check the needle and jet, make sure you don't have a .090 needle in a .100 thou jet......

Re: Hif44 Struggling To Tune

Posted: Tue Apr 20, 2021 7:40 pm
by Stopped-again
On the HIF carbs the mixture screw works the “wrong way round” turn clockwise to richen and anti clockwise to weaken. Hopefully not teaching Granny to suck eggs.(never really understood that phrase, never saw my Granny suck an egg)

Re: Hif44 Struggling To Tune

Posted: Wed Apr 21, 2021 12:11 am
by LuisM
Another tip when an engine runs Rich with an HIF carb is the cold start mechanism, if the the o-rings are cracked/perished the fueling will be hard to set up and on the rich side .

Cheers
Luís

Re: Hif44 Struggling To Tune

Posted: Thu Apr 22, 2021 8:48 am
by Zeemax_mini
Thanks all, that gives me a few things to start on! The carb was rebuilt with the engine so it shouldn't be the choke seal, but I'll take the carb off and check its fitted OK.

How can I check if the needle is the right size for the jet, and if it was the right size but the wrong needle for the engine would that give the symptoms I describe?

Cheers!

Dom