Tuesday, January 29, 2013

Closing in on the finish

Headed out to the garage tonight all ready to pull one of the carbs and clean it within an inch of its life. I decided I'd start with the mag side and pulled the choke cable. Thats when I noticed how little slack there was in the choke cable which prompted me to remember how the choke lever had felt weird yesterday. I pulled the other cable and it seemed short too. I followed the cables back to the lever and found the back had popped off and pulled back on strangely so the choke was always half engaged. Got that re-arranged, got the cables back in place, fired the sled up and it still ran like crap. For some reason I kept it running and after maybe a minute it make a little noise and idled perfectly!

I think that yesterday in running with the choke on I'd loaded some gas into the bottom end of the engine and what I saw today was that burning off and once it did the sled running right. It was late when I started so I didn't want to run the sled too much, make a bunch of noise and piss off my neighbors but I'm pretty pleased.

Unfortunately I noticed the headlight is out, I put my trouble light on the line to the seat and it lit up so either the bulb is burnt out or disconnected. I wouldn't be surprised if its burnt out.

Anyway I decided that since the carbs don't have to come off (probably) I'd put the seat on. That was an exercise in frustration. Here's a free hint that I should have already learned from farting around with the Ski-Doo, test fit the plywood before attaching it to the seat. I didn't make the cutout at the front deep enough or wide enough. Now I need to take the seat apart again, recut the base and reattach. I'll definitely trial fit the base before I reattach the foam though!

Anyway, getting closer, nearly there!

Monday, January 28, 2013

One other note on brakes

I got chastised by the boys around the table of truth over on the Yahoo Group "Vintage-Snowmobiles" for adding DOT 4 brake fluid in my Cobra. Apparently it originally came with DOT5 and as DOT 4 and DOT 5 are not interchangeable or even compatible my using DOT 4 is bad mojo. I'm reasonably sure what came out was DOT 4 as one of the guys says DOT 5 is usually tinted.

Anyway on Saturday I picked up a bottle of DOT 5, they sure don't give that stuff away! I pulled the drain at the caliper and mopped out the master cylinder. Then I refilled with DOT 5 and left the plug out of the caliper until only purple DOT 5 ran out. Its handy that its tinted... With any luck since I only topped up with DOT 4 it won't have had time to hurt anything.

This whole incident makes me wonder if the leaking brake on my TX-L was inadvertently caused by my use of DOT 4...

Straighten out!

Dug into the steering on my '79 Polaris Cobra today, the tie rod was bent badly:
It was a bugger to get out, had to shift the engine out of the way... I bent it back straight using an old brake disc as a mandrel and my 3# hammer to finish it, got it pretty good but apparently forgot to take a picture.

Installation was no big deal and I moved on to welding up the turn stop. It'd been welded, maybe several times before and I had to grind off a lot of old weld. Then I learned what the last welder knew, its a hard spot to weld in, the engine is really in the way, this is something that should be done with the engine completely out of the sled. Anyway I got it welded back on, its such an ugly job I won't post a pic, just know that its there!

So finally all ready I took it for a shake out ride before installing the seat and found its bogging badly on the low end, won't idle good once it warms up either and when it quits won't restart unless I hold the throttle wide open. I'm guessing I didn't get one or both of the carbs clean enough when I cleaned them. Interestingly this is similar symptoms to my Pantera. I'll have to pull the carbs and do a better job this time...
I also noticed that the sled doesn't seem to shift gears, which is to say it doesn't seem like the secondary clutch is opening. That said its really hard to tell what with the short space I've got to run it in my yard and the problems with the carbs. The secondary moves, I've had it open a couple times to remove and re-install the belt. I'll lube it good and see if that helps.

Oh well, one step forward, one step back. Fortunately we're closing in on the finish!

Take a seat

The seat on my 1979 Polaris Cobra was basically trashed. The cover had pulled back from the base which is a pretty common problem, and the sled had been left outside. That had caused the foam and wooden base to get totally saturated with water. I let it sit near the woodstove for a few days which got it basically dried out but the wood base was totally ruined. So I got a sheet of 3/8" plywood (which will help me with the '70 Ski-Doo as well) and cut out a new piece. Its actually a fairly complicated shape, it needs to fit around the light assembly at the rear and then around the lip that holds it up front. Plus there need to be two holes to attach at the rear. I painted the whole thing in a thick coat of black Rustoleum which makes it look original and should protect the wood. If I get another 30 years out of it I'll be satisfied. :)

The original base was molded into the foam so getting them apart without destroying the base (which I needed for a pattern) took some doing. When done I'd cut the foam in a couple places. I glued those back together and then glued the base onto the foam to keep them from sliding apart. Finally I wrapped my new seat cover over the top and stapled it to the base.

I bought the seat cover on eBay and I'll warn you that there are 2 versions, 1 is black, one is blue. I didn't notice that until I'd bought and received the black one. The original cover was blue. At this point after I'd cut the cover to make a hole for the taillights I'm not going to spend the money to get the correct one, after all it gives me a story to tell.

Anyway, once I get the rest of the sled completely ready (which means fixing the ski that only makes right turns) I'll mount the seat, but at this point I'm so close to being done I can taste it! If we only had some snow...

Friday, January 25, 2013

Whoops!

After coming to grips with the grips I decided it was a good time to take the Cobra for a rip around the yard. I'd had a little difficulty getting it started but considering it'd never really run enough to warm the engine up properly I'm not really concerned. This would also be the first ride since freeing up the brake, on the maiden voyage the sled was dragging badly because of that brake.

So the good news is with the brake released everything feels pretty spritely. The bad news is this:

Turns out the stop which should keep the ski from getting into that position is broken. It looks as though it was broken and rewelded poorly at some time in the past. Further forcing the ski back into place has bent the tie rod so that the right side ski is perpetually turning right. I'll have to fix the stop and straighten or at least shorten that right side tie rod to fix it.

On another note the seat is nearly ready. In getting the seat foam dry I finally had to resort to ripping the plywood base off. It was soaked and badly degraded. I got another sheet of plywood (which will help me with the Olympique too), cut and painted the base. Now I'm just waiting for it to dry before I finish. I'm debating gluing the base to the seat. Not sure what to do about that.

Got my grip on!

Last jobs on getting the heated grips wired up were to connect ground and power. For ground I pulled one of the screws that holds the handlebars in place, the Polly Heater grips come with a ring terminal that fit perfectly though I should have shortened the leads a little before crimping it together.
Finally for the hot lead there was a wire with a banana plug lying next to the fuel filter which was t-tapped into the voltage regulator. My test light show it was hot, I ran it through a 4a fuse to the switch.

I couldn't get the spade lugs Polly Heater provided to work with the wires since with the exception of the hot lead you're connecting 2 wires at a time so I used some other larger (and more protected) ones I had.

With everything connected I fired up the sled and flipped the switch, the headlight dimmed so clearly 2 things are true:
  1. Everything is wired up correctly
  2. The electrical system is marginal for these heaters.
On low its not so bad, the headlight dims but its not the end of the world. I don't think running the electrics full on will hurt anything but I should ask. Maybe I'll look into swapping in the lighting coils from a newer sled.

Wednesday, January 23, 2013

Work continues

Got just a few minutes to work on the Polaris today, got one more fuel line cut and installed. I'd started this last weekend but ran out of zip ties. I always zip tie the fuel lines on since the time I had them fall off the El Tigre while I was riding...
I tried to reinstall the left carb which I'd removed Sunday to install a jet I'd accidentally left out. I'd left the carb off because it made it much easier to install the fuel lines but I found with the carb boot cold (about 5F) I couldn't get the carb to go into it, the rubber was too hard.

So I'm kind of stuck, I can't finish wiring the grips until I can run the sled to prove the wire I think should be a hot lead really is. I can't run the sled until I get the left carb installed and I can't get the left carb installed without it being warmer. I dare not run a heater near the carb boot because the left fuel line is disconnected and I don't want to start a fire. Until I figure out how to warm that carb boot up I'm sunk.

On the seat front I finally had to tear the plywood base off the seat, it was holding moisture like crazy and I didn't want to install the seat with the new seat cover knowing I'd have to redo it soon. Although in the spring I still want to pull the seat, sand the tunnel and repaint. Clearly the moisture buildup there has been a problem for some time. Unfortunately I don't have any 3/8" plywood on hand and Angie took the pickup truck to work today so I could put the snow tires on my car. Tonight I'll plug in the car's block heater (its supposed to be below zero tonight) so she'll have no excuse not to take the car tomorrow.