Summit HAC and/or rejetting info needed

Coldfinger · Jan 12, 2009

For anyone that has the old cannister style H.A.C. like used from 1995-1998, can you tell me how far down the tube the needle should be and at what altitude?

I tried calling a few dealers to see if they stock the part but can't find it in stock. If someone had it in stock they could easily measure the needle depth.

Does anyone know what jets to run in a stock 1995 670 if the HAC is removed? I had a suggestion to begin with the Formula SS specs which seems like a close match but if anyone could tell me what jets work at 8-10k that would be better yet. Which hoses to block off and which ones to leave open?

Thanks!

Zachmandu · Jan 12, 2009

For removing HAC

On my '97 670, I run 280/300 w/ single pipe, 290/310 w/ twins, needle clip 2nd from the top, and 55 pilots. This is sea-level to 3000', and works for me at temps greater than 15-20 degrees. You would have to look at a jetting chart to jet yours accordingly. If I recall, factory MXz 670 stock jetting was 290/310, but they changed jetting requirements just about every year for the different sled variations using this motor. I find that the factory jetting to be just a tad rich.

For hoses, you have bowl vent nipples about 1/8" diameter on either side of carbs that need hoses hooked to them for vent lines, hanging them down under the carbs, about an inch or two under the bottom level of the bowls. You will also have about a 1/4" nipple mounted near the opening of the carb, just above the float bowls that need to be plugged. If you pull the HAC diaphragm out of the airbox, don't forget to tape the hole shut.

You will be MUCH happier once you ditch the HAC. If you insist on keeping it, I have two old HAC diaphragms laying around that I would GIVE away.

Coldfinger · Jan 12, 2009

Z- thanks for the info. Could you measure how deep the needle is in the HACs you have, at room temp? Easiest to use a toothpick to check depth and then measure the toothpick.

I'm not married to the HAC, but right now I'm looking for the easiest way to get it checked/rejetted because I am taking it to the mtns Friday (if I know it will work).

I don't want to spend time on the mtn messing with jetting so if I'm not sure I have it close enough to run, the guy who was going to ride it will have to stay home.

Here are some specs I found for the 670 engines (I assume these are sea level specs). I wonder how close I'd be if I use the SS specs for main jet, like if it would run well enough to do easy riding.

Yr 95 95 96 96
Model Summ FormSS Summ MXZ

Needle 7em73 7eg063 j87dp11-3 j87edy1
Needle jet 224aa4 224aa3 224aa2 224aa

Pilot jet 75 pj40 75 60

main pto 420 360 380 300
main mag 420 370 370 290

Pilot screw 1 1/8 1

float setting 19.6 18.1mm

Adjusting the Formula SS for 8-10k and 14-32 degrees F, the main jets would end up around 280-290 and drop one needle position. The chart indicates a 50 pilot so that goes up for some reason. Also calls for different needle, Z9224.

I was already running 65 pilots and 380 mains, so maybe if I just install 280-290 mains it will be close enough?

??

RBSDriver · Jan 14, 2009

zackmandu, i'm having some problems i think are related to my HAC but same deal, don't have a good one to test and don't want to remove it and mess with jetting. You say you still have 2 spare HAC's? Do you know if they are good? PM me i'm very interested.

thanks!

sledsrock · Jan 14, 2009

HAC info.........

Sorry guys I don't get on here much during the week....................

Coldfinger, I just measured the pin depth of the HAC on my sled, I'm at 4,800 ft. approx. 70 degrees depth of .330 in. (sorry, you'll have to convert it to mm)

Try this web site: www.greenskyadventures.com for a source of a new HAC. Now I have not contacted these guys for a couple of years. Good guys to talk to, they use these on the Rotax Ultra lights. Same exact part that Ski-Doo uses......p/n 09-710-02. You need to call these guys as just the HAC is not listed by p/n, give them your p/n and colored dot, there will be a second number on the HAC, example 12/03, that is the date of manufacture. You will more than likely have to set the pin depth, but it's not hard. Check your old HAC for a colored dot, either blue or yellow, they will need to match the colored dots - I have no idea what the difference is on the dots.

I hope this helps some what.

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Summit HAC and/or rejetting info needed

Coldfinger

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Zachmandu

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Coldfinger

Well-known member

RBSDriver

Free Member

sledsrock

Well-known member

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