weird rich/flooding condition, need help pls.

[RBSDriver]

I took my 95 summit 670 out for the first ride today and was soon met with frustration. When I bought the sled it needed new needle valves and seats to get running. I replaced them it it ran very well started on first pull. It was warmer when I did all the work (probably around 30-40F or so) so when I got it out yesterday is was near 0 F outside maybe a little colder. it started first pull like always, but lacked power and then flooded and stalled after i let it back down to idle. No matter what adjustments I made it seemed to just run rich/ and flood out if i didn't keep the gas on and it had low power no matter what. It would only do 30-40MPH tops at 6000 rpm.

What should i look at now? I'm kind of lost, i tried 1 turn out on the air/speed screws, all the way to 2/1/4 out in 1/4 turn increments. It also will only idle at 1500 with the idle screw even all the way screwed in now, but when it was warm when I did needle valve change and tuned carbs it was idleing at 2000 fine and everything seemed to be in good adjustment.
It also has new gas in it, plugs, and coil from parts unlimited since the last coil the wire clamps where broken off and the plug wires were loose in the oem coil

Now i think i need help to figure this one out a little more...

 

[ak]

Does it still have the HAC?

 

[RBSDriver]

Yes it has the HAC. All the hosesd are in the correct spots according to the diagrams

 

[LRD]

If it has primers those can sometimes dump fuel also.

 

[ak]

As suggested check your primer and the lines for leaks. I suggest removing the Hac they were a pain and when they Fail It will cause the sled to run very rich. You can jet your sled to a Formula ss 670 specs and reroute your vent lines to your carbs. Are you shure the rest of your sled, as in motor is Healthy.

Make shure your Float in the carbs are Slightly turned up it will help prevent flooding. And bring lots of spark plugs.

 

[RBSDriver]

I am sure the engine is in good condition. It looks like it had a rebuild not to long ago as the sled has 3500 miles on it. Cycl walls are great no carbon buildup on pistons and compression test gives good numbers 155 on both cylinders.

If i take the HAC off do I cap the opening in the carb where the HAC lines go into? And then just retune carb? Do i need to change anything else to remove the HAC?

It does not look like the primer is leaking down any fuel i could see air bubbles in the primer line when the sled was running and it's a brand new primer so I don't think that was it.

After looking under the hood alittle tonight i notice a little pool of thick black oil (didn't smell like gas) on the top of the y-pipe heat sheild under the clutch side exhaust valve. Not sure if this might be the sign of a over oiling problem but when I installed the carbs my oil pump was lined up with the hash line like it should be at closed throttle.

I'm still clueless, i suppose i can try removing the hAC to count that out first just let me know what i need to do to properly remove it from the system. Ie:capping off carbs or rerouting any lines...

 

[ak]

did you ever change the plugs when it was doing this? There is one line that runs to Hac from the crank case I think it was around the recoil area remove that line from the case side, some times those will get moisture in there and make run crappy also. To remove the Hac find a parts diagram and compare to formula ss 670. Four of the lines get reused two get blocked off.


www.hlsm.com

 

[onlyrotax]

Does it smoke alot, injection pump possibly stuck wide open ?? On my 98 summit with HAC I had to jet it down 2 sizes to get it to run right then things were fine, sometimes it seems like it will run a little rich until the first time you shut it off them it seems to recalibrate and runs fine.

 

[RBSDriver]

it smoked alot when running and there was a pool of thick blck oil unter the clutch side exhaust valve.

I kept having to change fuel soaked plug yesterday to get it started back up then ran fine just low power it would only do about 40 mph at 6500 rpm it would idle for a while then eventually stall and then i had to change fuel soked plug to get it running again. It would not stall if i kept on the throttle though

 

[RBSDriver]

Does it smoke alot, injection pump possibly stuck wide open ?? On my 98 summit with HAC I had to jet it down 2 sizes to get it to run right then things were fine, sometimes it seems like it will run a little rich until the first time you shut it off them it seems to recalibrate and runs fine.

is there anyway to check if the HAC is faulty? In my service manual is just says replace if suspected the problem and see if the problem goes away but i think the HAC is a pricey metal hockey puck to just throw a new one at it.

Also , i know the guy that owned it before me was not mechanically inclined he never got it running (it originally just needed new needle valves) but I know he had the carbs off. Maybe they are switched? There are no marks on them to tell but is there a way i can tell which numbers the main jets are on them when I take them off? Maybe my problem is just as simple as the carbs got switched around???

 

[rhino]

i had a simular problem with a 2001 summit. turned out to be a problem with the temp sending unit. the wire from the sending unit in the head had broken inside the plastic conector. Not sure if your sled has a computer brain or not but that was the fix for mine. i chased that problem for a month before i found it. good luck

 

[RBSDriver]

i had a simular problem with a 2001 summit. turned out to be a problem with the temp sending unit. the wire from the sending unit in the head had broken inside the plastic conector. Not sure if your sled has a computer brain or not but that was the fix for mine. i chased that problem for a month before i found it. good luck

yeah, it has a computer and a temp sender but i don't see how the computer or temp sender could change my fuel/air ratio or anything like that anyhow. it's not connected in anyway to the carbs gas, oil or air supply i assume it may only change timing if anything

 

[ak]

yeah, it has a computer and a temp sender but i don't see how the computer or temp sender could change my fuel/air ratio or anything like that anyhow. it's not connected in anyway to the carbs gas, oil or air supply i assume it may only change timing if anything

Your sled has HAC and in 01 it was DPM its two differnet things, Hac is manualy operated And Dpm Has electronic sensors.

 

[RBSDriver]

now this oil leaking out of the pto rave valve weep holes does this mean my valve bellow mayt be torn? Could even thius lead to a rich or flooding condition?

 

[RBSDriver]

AK, I was able to dive in to it today and here's what i got:

FUEL PUMP: checked and working properly

HAC: Thats still a mystery may work may not i don't know how to check the functionallity for it and I still have it hooked up to factory specs.

FLOATS: are working properly not fuel logged and are within specs

NEEDLE JETS: I replaced these a few months ago when i bought the sled. They are 1.5's mikuni brand.

****MAINJETS: both carbs have the same size stamped main "420" ******

stock mains are 380PTO and 370MAG I am not sure why both are the same and so large. Maybe possible engine work was done that requered larger mains? The commpression on this sled is 156 in both cylinders which is higher than what I hear most people have so maybe the head are milled or something like that to require larger mains? Or the guy who owned it hadn't a clue and through any old main in?

ANYHOW..

I put them back together and readjusted everything down to the oil pump to factory specs keeping the 420 mains in both carbs and it seems to run much much more powerful now. I punched it a bit down my street and it got rpm's around 7K which is a huge improvement from before and factory max rpm is somewhere around 7500-7800 i think. Maybe just a bad carb adjustment? but I will need to trailer it out this weekend to tell for sure, my street is nothing but an ice rink... It still seems to smell rich though unless thats just the nature of these machines? If i start it up for even 2 minutes my clothes are completely saturated with gassy exhaust stench... does that sound normal?

BTW: I forgot to mention before since adjusting the carbs initially when I got the sled and installed new needle valves and seat I got the pipe, can , and Y ceramic coated. I'm not sure if this would have effected the previous carb settings or notand require a re-tune but maybe just a thought...

Thanks for all the help and suggestions so far!

 

[cdnsleddog]

This sure sounds like it is flooding. Look in through the carb throats at rest and at idle. If there is a fuel running in I would suspect there is some kind of contaminent stuck in the needle and seat on that carb or the float hieght is too high.
Unless there was a stroker crank or big bore done to this engine there is no way the jet sizes need to be 5 or 6 sizes bigger than stock. Check with a doo tech to see if the jetting numbers you have are right. Good luck.

 

[RBSDriver]

380 and 370 jets are stock for this sled for sure... I'm operatiing on temps from -15 to -25 so i'm not sure if that may be reason that i found 420 jets in both carbs or not. I have no clue what the history of the motor was just that it looks like it had a top end not to long ago and the base gasket is farely new as well leading me to believe the lower end was opened up for something as well.

I'm not sure if i could or there is any way to tell if there are some major mods such as a stroker crank installed on this without splitting the case open unless you got one i would be interested...

It doesn't seem like it is flooding after i readjusted everything yesterday. Like i said it seems almost twice as power full and the rpms spike to 7K bumping the throttle. I will see for sure this weekend when I take it out for an official test. But it does leave a big exhaust stench all over your clothes even running it for a few minutes... and i'm not sure if it should be that pungent of and exhaust odor left behind...

 

[ak]

380 and 370 jets are stock for this sled for sure... I'm operatiing on temps from -15 to -25 so i'm not sure if that may be reason that i found 420 jets in both carbs or not. I have no clue what the history of the motor was just that it looks like it had a top end not to long ago and the base gasket is farely new as well leading me to believe the lower end was opened up for something as well.

I'm not sure if i could or there is any way to tell if there are some major mods such as a stroker crank installed on this without splitting the case open unless you got one i would be interested...

It doesn't seem like it is flooding after i readjusted everything yesterday. Like i said it seems almost twice as power full and the rpms spike to 7K bumping the throttle. I will see for sure this weekend when I take it out for an official test. But it does leave a big exhaust stench all over your clothes even running it for a few minutes... and i'm not sure if it should be that pungent of and exhaust odor left behind...

420 are stock for a 95 summit in 96 they went to 370 380. There is no reason you cant jet down some. The 95 forumula ss ran 370 380 also.

Jet it down and go Out and ride the sled a little. If the rave valves are leaking very bad it will affect the performance on top end. You will want to tear that down and see if a bellow is cracked are the oring are gasket is bad in there also.

 

[RBSDriver]

Thanks AK, i was told by someone that the 96 was exactly the same. (that is the service manual I have). I guess they were wrong. Do you know if I can get a adobe reader 95 manual somewhere online or do you have one maybe? If the jet sizes were different maybe alot of other little things are too...

I may just got to 370 and 380 I suppose there was a good reason doo switch to the smaller jets in the same motor and sleds the following year...

On the rave valves from the diagrams i have there are two clamps holding the bellow in place. The metal butterfly clamp on the inside and a larger (maybe zip tye type) clamp holding the outer part of the bellow to the plastic body. This outer clamp is non existent on both of my valve bellows. I even noticed each vavle bellow outer rim was halfway out of the groove on the plactic body. Maybe this is where the entire oil leaking valve issue is stemming from. From what I can tell the bellows look good and when manually moved in and out they seem to have proper resistance holding air inside the bellow. I am going to try and go to the dealer tomorrow and just get the clamp that are suppose to be there.

 

[ak]

Yep there should be a 360 degree spring that held the bellow on to the plastic cap. And a metel retainer that held the black rave caps.

I dont have are know where to get a service manual besides A ski doo shop CC skidoo.

I just look on the microfiche for jet part numbers.


Edit: The old raves had a zip tie holding the bellows in place the newer ones had the spring.