'79 Scorpion whip 440 questions - Snowmobile Forum: Your #1 Snowmobile Forum

ponchonutty · 06-16-2008, 10:23 AM

Hello again. It's been a while since I've been on here. It has been very trying times since last year at this time but I've made it so far! Anyhoo some of you may remember last year I bought a '81 TK440 that only had something like 600 miles on it but had a burnt piston. The guy gave me another sled for parts. Well, since the better sled only needed pistons I didn't touch the other one. I was told that the Whip runs but the crank case seals are bad. It probably in fair to poor shape otherwise. Most of the mechanicals are there but need severe cleaning. The tunnel looks great and the belly only has one crack. The hood is near perfect, just faded. The seat is toast.

Now, I am not sure if I should try to get this running or not or just scrap it out. I've wrenched on motors before but normally just the upper sides. Never replaced a crank seal. Is it overly hard or are there special tools needed to do this fix??? I originally thought of cleaning it up and getting it running for the kids to beat on since it was free. Or, sell it and get an old El Tigre since that's what I've been looking for anyways.

**RJ Gleason** · 06-16-2008, 08:10 PM

If it is just the clutch side seal (most common one that fails), you only have to pull the clutch and can change out the seal without even cracking the case.
Just pry out the old one and tap in a new one.

ponchonutty · 06-16-2008, 10:06 PM

Well, not sure. This sled was sitting at a shop that mainly deals with cycles and ATV's. The original owner brought it in stating it was very hard to start when warm. It's got great compression and it would fire if I threw some gas down the carb. That's as far as it's gotten at this point. So, how do I determine if ANYTHING is wrong with this sled? This shop also thought my seal was bad on my last sled but I only had them redo the top end and it was great.

JheLrey · 06-16-2008, 11:56 PM

You will need to get it running and idleing... Then you take carb cleaner and spray it around the case where it splits. If the motor revs up, it needs to seals, if not, you are okay.

ponchonutty · 06-17-2008, 07:09 PM

OK. I'll try that and will post back. I'm a little busy here for a while so it'll be a bit before I get back on here unless something gives. Also, does anyone know if this sled should have one of those fuel pulse pumps like the one in my sig does? I looked quickly but didn't see one down on the mounting area about where they were on my other sleds.

**RJ Gleason** · 06-18-2008, 08:34 AM

Easy enough to tell, what carb does it have on it?
Even a Wahlbro or Tillotson use a pulse pump, it's just part of the carb.

ponchonutty · 06-18-2008, 09:12 AM

I think it's a single Mikuni like what the others had but again, when I get the time to look at things I'll report back.

ponchonutty · 07-13-2008, 11:21 PM

Alright. Today I decided to mess around with the sled. Spent a few hours cleaning it. I took a look at the carb and it is a Wahbro with the pulse pump on the top. I took a small container and put fresh fuel in it and stuck a hose from that to the carb. After a few pulls it fired right up. Seemed to idle and rev just fine. I took some brake cleaner and sprayed around the motor to see if it would rev up. Even sprayed water as well but it never changed pitch. It kept running fine. So far, the only thing I saw wrong other than the wiring was that the carb was leaking a little from somewhere. $20 for a rebuild kit should fix that. Need to find a sheet on how the wiring is suppose to be especially for the tach since it didn't work.

JheLrey · 07-14-2008, 12:46 AM

Water will not do it... Its the fumes or actual liquid from carb cleaner that will make the engine rev up as it gets too much "fuel."

ponchonutty · 07-14-2008, 01:45 PM

OK but it should have changed pitch with brake cleaner correct? I don't usually have carb cleaner in the shop. I like brake cleaner because I usually can get bigger cans for about the same price.

**RJ Gleason** · 07-14-2008, 07:32 PM

Brake cleaner would work too as it is flammable.

For the tach, check for two yellow wires.
One will go to the regulator and the rest of the lights. The other one will be used to run the tach alone.

ponchonutty · 07-15-2008, 08:39 AM

Alright good. The story behind this sled is that a customer brought it into a local cycle shop with starting problems. He stated that the summer before he had the engine rebuilt but now when it had been running for a long time it'd be almost impossible to start after that. The shop said the lower seal or crank seal was out of it and that's why he was having this problem. Well, the owner decided that it'd cost more to fix than what it's worth. For 2 years it sat outside the shop waiting for the owner to pick it up but he ended up thinking it wasn't even worth that.

That's where I come in. In my quests to do other Scorpions I actually bought some parts off of this poor sled. Then, when I went to buy another Scorpion, this was thrown in for parts. Well, even with my having picked a few minor parts off of this thing it was still about 90% complete. The only big thing I see missing is the airbox that's right off of the carb. Everything else is there.

Well, my gauge of "is it worth it?" is that if it starts and runs fine then it is worth it! Like I said before I was skeptical about it running because the shop where this was to be fixed originally is a good shop. The even said it was barely good for parts. Now it does look like it's had a rough life. The tunnel is nice and straight but the rear end looks like it bottomed out pretty hard and the front belly pan has been worked on before. The seat is horrid. Most of everything else looks decent so I plan to tackle it.

The hood is being prepped for paint, the seat is waiting for my wife's uncle to recover it, ordered a carb kit, and waiting for new rivits. Those that have followed my other builds know what I like to do, replace ALL rivits!

Here's some pics with about 4 hours worth of work into it at this point. I already blasted the skis last year when doing the '81 tk440. I also re-enameled the skis as well. So far the work has consisted of just cleaning and minor tearing down of the sled. I've got it down to where I'm happy and slowly the reassemble will begin.

**RJ Gleason** · 07-15-2008, 12:42 PM

Another good sled saved from the junk heap and given new life.
Hooray for you!

You use the same criteria that I do, if the engine is good, it's worth fixing up.

ponchonutty · 07-15-2008, 10:04 PM

Yeah this is probably the roughest one I've picked to work on to date. Most of all the controls on the handlebar are crap, the primer is missing, the choke is stuck, and just about every nut/bolt/ or rivet is loose if it's not missing. But I guess if I get it running it'll make it that much more to enjoy.

ponchonutty · 07-17-2008, 07:44 AM

RJ. Have another question. When getting my carb kit I asked the guys there about getting a new primer as well as a choke lever. They said that I didn't need both. One or the other is plenty otherwise I'll end up fouling up the plugs. They said by using the throttle for a few seconds, the motor should be up to where it should be to run without using a choke. What do you think????

**RJ Gleason** · 07-17-2008, 11:18 AM

Someone probably put a primer on because the did not know how to fix the choke.
You do not need both.

ponchonutty · 07-17-2008, 05:28 PM

Well, which one should I use? I liked the primer on my other Scorpions.

**RJ Gleason** · 07-18-2008, 08:30 AM

Your choice.
The chokes on the Wahlbro have always been problematic, I would use a primer myself.

ponchonutty · 07-18-2008, 07:07 PM

OK. I was leaning towards the primer anyways. THANKS!!!

**RJ Gleason** · 07-18-2008, 11:13 PM

Of course, unless you are absolutely wedded to the idea of keeping it all original, I'd dump the Walhbro carb and put on a Mikuni and pump.