1996 Summit 670 problems

[Toy4Fun]

I recently traded for a 1996 Summit 670 and it has some issues. It has some upgrades that I am trying to figure out. It has twin pipes and a pyrometer, the clutch is reworked, and the HAC system has been eliminated. The previous owner said it didn't perform well when he took it to the mountains, it was starving for fuel. I went through the carbs to see what was in them for jets, 360 on the PTO side and 340 on the Mag side with the needles in the second slot. Does that sound right? The pipe with the smaller jet heats up quicker than the one with the larger jet, yet are about even at wide open throttle. The plugs look good from what I can see. Does that sound normal?

Should I look to put another HAC system on it or look at aftermarket compensator? I've read good things about the ATAAC system from Holtzman, also Tempra Flow. This machine will see some mountain riding.

The oil injection system is not being used and it's been running pre-mix. I am wondering why would someone switch to premix? Everything is there, and now that I have the electrical system working, there is an annoying red light to tell me its out of oil! Should I eliminate the system all together or make sure it is working and refill the tank?

What premix ratio is best for this machine? 32:1 or 40:1 ,I'm using Ski doo synthetic blend.

Finally, the machine has 8 tooth drivers and a 136x 2" track, which is the better track upgrade for this engine, 144 or 151"? I will ride powder and some mountains with it.

I'm already impressed with the power of this machine, with the carbon fiber trailing arms and plastic skis, the front end likes to come off the snow!

 

[magnet]

go with the 151 works great. i ride a 99x model. with pipes and pods 360 sounds a bout right maybe a litle small but your probably higher elevation then i am i am around 2500ft or so. in my x i have went to 420s but still have the dpm. with the 350s in it stock i was running it out of fuel at full throttle.what is your pyro telling you? max should be around 1250 or so depending on sensor location what do the plugs and piston wash look like.one cylinder heating up ,more than the other could be your carbs need to be synced. noticed mine did the same thing when i put on the digitron and the twin pipes. could not believe how far out they were before and machine still ran great with the single pipe. my one carb was probably open 1/8" just about before the other one even started to move.
people took off the injection and went to premix as these doos had a plastic gear drive for the il pump and they failed once in awhile. mixing ensured that you didnt run your sled out of oil. i have 4500 miles or so on mine necer had an issue though. as for the light just unplug it in the gauge pod. if everything is there for the oil inj system not sure why they would delete it. is the crankcase tube linked together or still running out of the tank. if it is still running out of the tank you may be close to running the bottom end out of oil check it out close.
good luck nice sleds love mine.

 

[Toy4Fun]

Yeah, when I saw the pics of how to delete the oil system right my heart skipped a beat. I'll look tonight and see if the tubes are hooked up to bypass the pump. My thought is to hook it back up, or maybe buy a new pump first to ensure its longevity. I'm not hardcore enough to pre mix my fuel every ride. I haven't been able to take it out and really open it up to see how the temps are, in the short bursts of wide open around my house the temps haven't reached 1000 yet.
I'm really wondering about putting an ATAAC on it so I don't have to worry about jetting and just enjoy the riding...

 

[magnet]

not sure if you can do it but it was suggested to me when i sold my 96 that had the hac removed. you can go to projets for real cheap and apparently they work good. have heard lots of issues with the attac system i think there are alot better out there for the same money.

 

[Toy4Fun]

I'm not familiar with projets. Are they like Dial a jets or IntelAjet made by the same company Thunder products?

 

[magnet]

i think so never used them but apparently they a cheeeeeeeppp and its easy to reset for alt. might have to google it.
ithink thats what they were called anyways.

 

[Toy4Fun]

I couldn't find anything, is Power Jet what you are thinking of?

 

[Toy4Fun]

What is the best way to test the oil injection before I rely on it? It all seems to be there and I'd like the ease of not having to pre-mix.

 

[Modman]

What is the best way to test the oil injection before I rely on it? It all seems to be there and I'd like the ease of not having to pre-mix.

??? Premix is just as easy as pouring oil into the tank. not sure why you'd want to go back to relying on the oil pump to fail.....

Powerjets are what you are looking for. Not made by the same company as dial-a-jets. Dial a jets add air, powerjets add fuel. You want powerjets. They are an air jet for a different application (I forget what) and it has a dump tube soldered into them and you cut it to length for your carb throat, depending on where you want to add fuel. 1/4 turn is one main jet size, you set up your jetting so that you can dial it in as you go up - basically u make it as lean as your lowest riding elevation, then you crank the dial in as you go up in elevation and this leans out your fuel. Its just like changing main jets but you can do it in about 3 seconds and you don't even have to shut the sled off. Have them on both my sleds, they work awesome. I have the isntructions on PDF at work, PM me and I will post them Monday, if you search on this website I'm pretty sure I've posted them before, search under powerjets and you will probably find them. they explain everything. Lots of turbo guys use them also to add fuel on the top circuit. I use the one way check valves from Thunder Products though, it keeps fuel right at the powerjet on the top of the carb, doesn't let it drop back down to the float bowl height. So you always have fuel right at the powerjet.

1200PSI on Snowest (Brad Wursten) Power Addiction Motorsports (search the internet for that company) can sell you powerjets, or Jack Harris Racing (search Nitrosherriff on the internet).

 

[DRD]

If you are ambitious you can build your own powerjets, the valves come from a company called Clippard.
I have everything you need to put a 151 on that chassis. Drop brackets, bulkhead "wings" and rail extensions. I also have a skid from a 99 with extensions to go to 159".
I like a 32:1 ratio.

 

[Modman]

If you are ambitious you can build your own powerjets, the valves come from a company called Clippard.
I have everything you need to put a 151 on that chassis. Drop brackets, bulkhead "wings" and rail extensions. I also have a skid from a 99 with extensions to go to 159".
I like a 32:1 ratio.

LOL thanks I was too lazy to go to the garage and read the side of the powerjet....

 

[Toy4Fun]

I'm still having trouble dialing the carbs in. I took it out for a ride and ended up flooding it majorly. Now I can only get it to run on one cylinder? I pulled the carbs and cleaned them and went up one jet size in the main, but can't get the cylinder to fire. It has spark and compression, even a new plug. I've pulled it a bunch with the plugs out to clear it... Any ideas?

 

[posnick]

have you done a compression test? If you have good spark and good fuel, then it could be bad compression.

 

[Toy4Fun]

Compression is 130 per side. I figured out today that there is water in the fuel so the carbs froze and possibly a fuel line. I've got to filter the water out and warm things up and run some Heet through the tank.