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96 Summit 670 HAC fuel issue, Help please!!

C
Oct 14, 2013
4
0
1
32
Merritt, BC
Hey everyone, so I bought my first sled a couple days ago and its having some sort of fuel problems. When cold, its the biggest b**ch to start, basically prime it and just keep pulling till it stumbles (10-30 pulls later), prime it again and givr a pull while yaking the throttle, now shes running. Then once its warmed up its 1 or 2 easy pulls (i think the voltage regulator is also on its way out, the headlight doesnt usually flash the first couple of pulls). Once its running it seems to run pretty strong, though i havnt taken it out yet due to a snapped steering post, but lifted the back and ran the piss outta the motor.

So yesterday I pulled the carbs off and took them apart, both are clean clean clean inside, no water, floats and everything are free and clear and jets are not plugged. So put it all back together, pulled the plugs and cycled the motor a few times, and it looks like one of the cylinders is getting ALOT of fuel and the other is getting pretty much non...

Went outside late lastnight before calling it a night and there was a pile of pink snow under it, could not figure out for the life of me where all this fuel came from (leaks abit where primer hose splits from main fuel line a bit but doesnt look too bad). This morning when I went to go inspect it with some better lighting than a headlamp. nothing was dripping but there was lots of fuel in the belly pan. I fired it up and moved it out back out of the way and when i shut it off, the carb that was getting all the fuel yesterday pissed out a bunch of gas from one of the breather hoses... theres my leak im guessing.

Why is this one carb getting so much fuel??

also if anyones got a set of pipes and a can for this bad boy, i would be interested.

Thanks in advanced for any input
 
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L

letrbuck

New member
Jun 6, 2013
62
4
8
Montana
hac

I own a couple of these my self and have dealt with similar issues I'll try to help out anybody else can chime in if I miss something
first thing I would do is fix the fuel leak on the primer line when you do get it going it'll suck air and you'll have hanging idle issues
second thing make sure your running resistor type plugs my 583 wont run worth beans without them like BR9es or BR9Yes
and biggest problem is your HAC take visual note of where the lines all run remove the lines take the HAC out of the air box on the back side there is a screw probably covered in blue locktite scrape it off around the edges of the screw and the slot break the screw loose take it out "towards the motor if mounted" and you'll expose the needle just do it enough to grab it remove punch replace the screw with oil on o ring and threads this will hold the diaphragm out then back the screw out little by little til you reach 3-5mm from face of HAC body to tip of needle measure using calipers may take a couple times but it's simple to try again theres another post here that goes more in depth I read about it on the DOO Talk forum really simple and it works
and lastly with the new plugs make sure you gap them correctly
this is all assuming the carbs are cleaned if one carbs dumping fuel needle valve may be stuck open I'm no mechanic but can't afford to pay one and usually fix by trial and error and info on here from others
 
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R

Red-eye

Well-known member
Dec 3, 2008
1,342
328
83
Sparwood, B.C. Can.
Float bowl needle and seat leaking on one side. Primer has a rep for leaking by. Always shut off the fuel when not in use.(esp on a hill) Change you plugs after fouling.
 
C
Oct 14, 2013
4
0
1
32
Merritt, BC
the hac is in the airbox hey? i dont have an airbox, someone put some mono pods on this thing, could that be contributing to the problem if it hasnt been jetted accordingly?

Ill take a look at the needle on that carb tomorrow, thanks for the info so far
 

Coldfinger

Well-known member
Lifetime Membership
Nov 26, 2007
2,351
538
113
Nebraska
The hac unit on my old 670 was just mounted to air box.

The hac unit can be recalibrated. I came across the info earlier today and I saved it. If needed send me a pm as I don't usually visit this doo forum.

I think I have some info on jetting too.

All the info I have is links to web sites.
 

summit800

Well-known member
Lifetime Membership
Jul 29, 2001
969
153
43
Graham, wa.
so when you have your carbs apart with the bowl off turn upside down and raise the floats just above level ,also check your primer they go bad and will siphon fuel from tank, not a big fan of pods on that motor and if they got rid of the hac your going to be alot smaller on both main and pilot jets from stock application!
 
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