Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

I know this is not a moped, but figured a snow bike wasn't too far off. Anyways, I've got 2 Chrysler Sno-Runner's that I can't get started. They both have new spark plugs, replacement carb kits and fuel lines with inline fuel filters. The first bike has a weak spark, so I think a new engine coil would remedy that problem. Not sure why the second bike won't start, it has fuel, spark and compression. The gas cap vent is open and the on/off switch is in the ON position. I also checked out the reeds and they appear to be in good shape, no cracking or warping. I've tried pulling the recoil starter with the decompression button pushed in and pulled out along with the carb on full choke, 1/2 choke and fully open. Any advice would be much appreciated. I want to have these things going before we get some decent snow.

Thanks

Re: Sno-Runner won't start

remove the thick head gasket with a allen wrench

set the idle screw high

then set the H and L screws to the manual.

mine burnt up, but I had em good.

Carb works like chainsaw

checks bulbs for shorts, tail and headlamp

Re: Sno-Runner won't start

Overpriced Parts /

Put a half of a soda straw of gas oil mix in the plug hole to prime

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Thanks Johnny.

I've got the high performance models, so they both should just have the 1 thin head gasket. I'll have to double check that when I get home today.

The H and L screws were both set to the manual specifications, 1-1/8 turns open. The idle stop screw was set to 1 turn open, I believe that is a high idle speed setting, correct? Should I turn it all the way clockwise until it stops?

Also, the manual says the the spark plug gap should be .030, but the guy from snorunner.com told me it should be .035. Not sure if it really matters as long as it's somewhere in that range, thoughts?

I'll have to check both the bulbs in the headlight and taillight, hopefully that's the problem.

Let me know if you think of anything else.

Re: Sno-Runner won't start

You need to make sure your diaphragm in your Tillotson carburetor is pumping fuel. Most likely the needle is stuck in the seat. This is a common problem for Tillotson carbs. I have blown compressed air back through the fuel line to free the needle. You will know if the needle is loose from the seat only if air comes out of carburetor mouth. This is just a quick test/fix. I have only done this on a fresh carb. rebuild that has sat for a season, rather than disassembling the carb again.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Hey Keith,

Yeah, that could be the problem. I actually (mostly) rebuilt both the carbs with new carb kits, but I couldn't get a socket wrench over the nut that the needle seats into, see attached circled in pink. The space is super tight, the socket needs to be incredibly thin if I'm gonna have a chance of fitting it in there and taking it off to replace with new one. The nut also has a new piece of rubber that the needle will seat into. Let me know if you have any other ideas about getting that nut out of there.

Thanks

Tillotson_Carb_1.jpg

Re: Sno-Runner won't start

I never had to replace a seat on a Tillotson before. I just made sure the seat was clean. Use a Q-tip and carburetor cleaner. Twist the Q-tip as if you were polishing it. You may need to remove some fuzz from the Q-tip to make it fit. If the needle is rubber tipped, make sure it does not come in contact with the carb. cleaner, as the cleaner will swell the rubber. Use gas to clean if rubber tipped. Use compressed air and reassemble the stack.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Alright, I'll try that. The tip is metal on the needle, so I won't have to worry about that. I would still like to replace the nut that the needle fits into along with that rubber piece, maybe I'll try to find a thin socket at the hardware store tonight.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

I just talked to a guy at Discount Marine and he said that I'll need a nut driver in order to get this part off. Once I replace those pieces I'll let you know if I get it started.

Re: Sno-Runner won't start

The fuel filter your using should be the type with the check ball inside, so the filter will allow fuel to be drawn up to the carburetor and not drain back into the tank. This is a must have part, because the carburetor is higher and further away from the fuel draw. Also, the fuel line should be long enough so the filter reaches the bottom of the tank, but short enough so the filter moves from side to side. Chrysler Marine states 24:1, you should running between 40:1 and 50:1 with a good injector 2 cycle oil (Amsoil) or snowmobile injector oil. 24:1 is way too thick.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Yeah, both my fuel filters have the check ball inside that doesn't allow the fuel to be drawn back into the carb. My fuel line also goes to the bottom of the tank and is short enough to move side to side. I thought the 24:1 ratio was a lot of oil. That's what I'm currently running with some 2 cycle outboard marine oil. If I still can't get it started after I replace the seat/inlet seal nut I'll dump the gas a replace with the 40:1 or 50:1 ratio of the Amosil 2 cycle injector oil. I cleaned out the seat/inlet seal nut with a q-tip swab and carb cleaner like you said. It got rid of a lot of the gunk that was probably making the needle stick, but I still want to replace that part altogether before I put the carb back on and give it a rip. Hopefully I can find the 5/16 nut driver today to take it off and replace tonight. I posted a blurry pic so everyone knows what carb part i'm referring to.

IMG_2202.JPG

Re: Sno-Runner won't start

Definitely green inside. That should clean up, if you have a new seat and the tool to remove it , perfect!

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

That's actually the green rubber seal that the needle seats into at the bottom of the nut, I had already cleaned it up. Trust me, it looks way better. I just found a socket at Ace Hardware that will fit in that extremely tight spot. It's 5/16 hex socket with an outer diameter of 7/8. Thanks for all your help, I'll let you know if I have any further troubles.

Re: Sno-Runner won't start

Bingo, that's your problem! Take that o-ring/seal out of there. I've worked on many Tillotson carburetors including your HL320a and never have I seen a gasket installed in there. I believe the needle is hanging up because of it. The needle is supposed to sit at the bottom of the brass seat and move freely. The needle is actuated by the fulcrum and diaphragm. Read up on "Fulcrum Adjustment".

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Oh man, I just read your last post. I already replaced the nuts along with the new green o-ring/seals on both my carbs and installed them on the Sno-Runners last night. Both the carbs already had the green o-ring seals and so did the 2 new carb kits I replaced them with, so I would think they were there for a reason. I'll give them a try with them in, but if they still won't go then I'll be sure to take both those seals out and try that. Thanks

Re: Sno-Runner won't start

Yes, I would remove them. Check the exploded view of the carb., no seal, only a gasket beneath the seat. Like I said, I have never seen that before. You have to remember these Snorunners/Snorabbits have changed hands probably more times than you think. That seal was probably put there for some overly rich problem, which was the wrong thing to do.

Re: Sno-Runner won't start

Try this, with the fulcrum removed and the needle in the seat, put your finger over the end of the needle and with light pressure push down on the needle. Then flip the carb. over, the needle should fall out.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Sure thing, if I can't get them running with those seals in I'll definitely take them out and give it a try. Thanks for the help.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Huzzah! I got one of the Sno-Runner's going last night. If I start having issues I'll def take out that green rubber o-ring/seat seal. I'm going to try the other one with the weak spark tonight, maybe it will be enough to get it going before I buy a new engine coil.

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Can't believe it, but the Sno-Runner with the weak spark actually started with very little effort. Just waiting on some snow now.

Re: Sno-Runner won't start

Jumping onto this just over a year later ^^

I think I have the same problem with my Sno-Runner that just crawled out of the woodwork. Replaced all the fuel lines but couldn't get them to draw fuel from the tank. I even manually put fuel into the female coupling and depressed the needle in it to fill the hose that feeds the carb, but no luck.

I attached a copy of the owner's manual, if you jump to pages 32 and 33, I assume it's illustration part no. 9 labelled "Seat and gasket, inlet needle" that needed taking apart and cleaning?

As a side note, I do have one of the Canadian Sno-Runners that has the ignition key as well the bilingual stickers. I highly doubt this has anything to do with either of those differences though.

Thanks!

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

So do you know if your carburetor is actually pulling gas into the fuel lines? Also, did you replace the fuel line and filter that are located inside the gas tank? If the carb isn’t pulling gas then this is more than likely your problem. The fuel lines in the tanks of both of my Sno-Runners were completely deteriorated and in pieces inside the tank, see pages 18 and 19 (Illus No. 19 and 20). I would recommend on using clear polyurethane fuel line so you can see if fuel is actually flowing to the carb.

You need to clean out the carb really well if you haven’t done so already. I would also get a carb re-build kit, it will save you a lot of headaches. I’ve include links to the carb re-build kit along with a carb rebuild video and the fuel line and filter that’s located inside the gas tank. You can find the fuel line and filter on Amazon for way cheaper than the Sno-Runner website, this is just an example of what they look like.

https://www.amazon.com/dp/B0078SQWQI/

http://snorunner.com/products/fuel-line-kit-disconnect

Re: Sno-Runner won't start

Yes, I replaced everything fuel line related both in and outside the tank. I had the carb rebuilt at a carb shop a year or so ago, but lord knows if they actually did anything. I have a clear line that I can see the fuel in, but I am 99% the carb isn't pulling any fuel. As I said, I manually filled the line and that fuel is still there, even after pulling the start hundreds of times.

Will look into the carb when I get a chance and will post back here.

Re: Sno-Runner won't start

Had a day off and took a look at it. Carburetor was in fact rebuilt, never seen one so clean. Started putting it all back together and I heard a rattle in the throttle assembly that attaches to the carb. Long story short, the screw that holds the lever in place had wiggled free. Started after 3 pulls once I had it all back together.

Wasn't idling well so I was adjusting the three screws when the rip cord broke, so that's next. Gotta love tinkering.

snorunner fuel supply

rich almquist /

my snorunner doesn't seem to get fuel past quick disconnect under tank leading to carb. if I push in on fitting in Tank above disconnect with small screwdriver fuel flows fine. how does quick disconnect operate? HELP PLEASE

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

Did you make sure to open the vent on top of the fuel tank cap? If not, then fuel won't flow to the carb. Also, make sure that the hole in the vent screw isn't clogged with any debris.

Re: Sno-Runner won't start

rich almquist /

I will check.is fuel supposed to run through that hose at a steady pace or a trickle?

Re: Sno-Runner won't start

Dr. Mantis Toboggan M.D. /

I honestly can't remember off the top of my head, but I felt like it was kind of a gradual flow until it completely filled up the exterior fuel line to the carb. Make sure that the gas tanks interior fuel line isn't kinked and that the in-line fuel filter isn't clogged with sediment. Also, you have to have a decent amount of gas in the tank in order for the carb to pull the fuel correctly. I have a PDF of the Sno-Runner Service Manual and Owners Manual if you need it. Just send me a PM with your email address and I'll pass them along.

Re: Sno-Runner won't start

rich almquist /

I will check more. THANK YOU

Re: Sno-Runner won't start

Did you manage to get this figured out? I had the same issue when I was dealing with my issues above. Make sure the throttle assembly that attaches to the carb is correctly installed and that the screw that holds the little lever is in fact screwed into the carb. Mine actually isn't holding well and it comes back out. Going to maybe try an aftermarket screw and see if it holds any better. Might require the purchase of a new throttle assembly ($$$$) if it is stripped.

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