78 Spitfire project

[400brian]

I think we are ready to install the track. I cleaned up the bearing flanges and have the driveshaft configured for installation.

The clutch side bearing is installed into the tunnel, and I am fighting the urge to toss the track in before the grandson is here to witness it.

[400brian]

The Grandkids were out on Monday, and we got to work on getting the track installed. As you can see, we tossed the track into the tunnel, and got the drive and idler shafts installed.

We have yet to be able to bolt the suspension in. With the sled on its back, we cannot pull the suspension back far enough to get the front arms anywhere near the holes in the tunnel. It appears that we are going to be forced to lay the sled on its side, and try it that way. I have been putting tracks and suspensions in JD sleds for 20 years, and have never had problems as I have had with the last two sleds in getting the suspensions bolted in.

[400brian]

Success! Today we we broke down and laid the sled on its side and installed the suspension like the book suggests. It took a bit of messing around, but with my wife holding the sled on its side, myself wiggling the suspension around, Galen was able to get the front bolts in and snugged up!

We then set the chassis back on the horses, pried the rear shaft into the tunnel, and then quite easily installed the rear bolts and put the rear springs back on their perches. With a final tightening with a breaker bar, we declared victory!

[400brian]

Big day, the Spitfire is on the lift!

Once the track and suspension is in, it all seems downhill for me.

I installed the handle bar today, the steering needs to be installed now for best access. The tie rods and spindle arms haven't been painted yet, so that is the next priority.

[400brian]

Cleaned up and painted the steering parts, and pulled the engine off the bench from where it has sat since 2020.

The engine needs to be cleaned up a bit, but I did install the base plate in preparation of installation.

The grandson wants to be here to see the engine set back into the sled, so we are working on getting that set up.

[snowmoer]

Great progress! It is looking like a snowmobile again.

[400brian]

Monday I cleaned up the hardware for the steering components and the motor mounts in preparation for a Tuesday workday.

The grandson arrived Tuesday afternoon and we got right to work.

We started by knocking out the original spindle bushings and replacing them with new ones. Once that was done, we put the shim washers on and added a bit of grease before we slid the spindles into place. Two more shims went on, then the steering arms. I had marked the position of the arms with a chisel before disassembly which helped a lot. The bolts were then installed in the arms to hold everything in position.

I then pulled out the 5/8" rod I had bought to align the 78 LF steering, and slid it through the spindles to lock them parallel to each other. With the handle bar pointing straight ahead, we then adjusted the tie rods so we could get the center bolt in. With that done, we went to work installing the custom fabricated steering arm stop I'd had fabricated to replace the one that was missing. That had the steering system looking pretty good, so the only thing left was to toss the engine in.

Looking back to the beginning of this thread, I noted that it has been 6 years since I did the work on the engine. So, the engine has been sitting on the bench collecting garage crud for 6 years. I blew the loose stuff off, then we wiped it down with Simple green and Windex to get it looking better. I lowered the lift a bit, then grabbed the engine and set in place.

I handed Galen the rear motor mount bolts and told him to crawl under the sled and poke the bolts through the holes in front of the track. It took a bit of trial and error, but he figured it out and I soon had the nuts and washers on the bolts. We then moved up to the front and installed the front two bolts, which went much better. We then tightened all four bolts and declared victory!

It was pizza and cookie time at this point, but I said; "one more thing". I dug out the Spitfire clutch alignment tool that I had never used before, cleaned and oiled the tube, and slid it on the driveshaft. It was quickly revealed that just as had happened back when I was finishing the 78 LF, despite the fact that I had put the motor plate back on the engine exactly where the witness marks indicated it had been previously, the engine is too far to the rear, a 1/4" or thereabouts.

Galen wanted to know what we had to do to fix this? When I told him that I had fixed it on the LF by pulling the engine back off and moving the plate on the engine and re-installing it, he indicated that he was not all that happy about going through all that again! Yeah, I hear ya! I have a plan on how to loosen the 4 bolts under the engine to move it forward a bit, I'll share it if it works.

This was about as much obvious progress we have ever made in one short work session, and it comes on the heels of getting the track installation finished, so he was pretty happy about what we had done.

[400brian]

On Wednesday I removed the recoil, and with 3 different wrenches, I loosened the 4 engine mounting bolts and slid it forward until the alignment tool dropped into place. With that done, we were go for any part we wanted to bolt onto the machine! I started laying out parts and getting ready for the next work day.

Thursday we got a lot done in a short amount of time, as I had things ready to go.

I had polished up the brake disc, the half moon key, located a new anti-rattle spring, cleaned the brake housing, the actuating pins, and painted the lever, then assembled the NOS speedo kit.

As soon as the grandson and I were settled in the garage, we bolted it all onto the sled. It is now waiting on final adjustment.

Next we pop riveted the rebuilt fuel pump on, slid the carb into the boot, and started running the fuel and pulse lines, putting spring clamps at each end.

The required shims had been placed on the driveshaft, so after brushing a bit of grease on the shaft and inside the secondary, I slid it on the shaft, and started hunting for the groove with the key. After flipping the key end for end, it slid into place. A bit of locktite was applied to the threads of the bolt, it was wiggled into place, and he tightened it down.

We were working on the muffler bracket when his mother arrived to take him to swimming lessons. I took the recoil home and cleaned on it, it was just too gray and furry to tolerate.

It was a good day!

[400brian]

On Friday June 12th, I was working on bar controls. I installed an NOS throttle block because the original was cracked. I had a new aftermarket kill switch in inventory, so that went in. Both the kill and dimmer switches on the Spit were seized, and I could not salvage them.

I also did a trial fit of the exhaust parts, figuring out what I needed for hardware and such.

And lastly, I pulled out the new 3D printed brake block I had gotten from New Breed, and did some trial fitting of it.

[400brian]

On Saturday the 13th, I finished re-working the 3D printed brake block, I had to open up the holes for the brake cable and the brake switch, and I re-shaped the area that the hand lever fitted to. Satisfied with it, I installed the cable to the brake actuator and to the brake block and lever. I now have brakes!

I looked in my inventory of parts and found I had seemingly used the last aftermarket dimmer switch on the 78 Liquifire last winter. I thought I had a handle bar out in my used parts pile, and when I found it I discovered it had two good switches! So the dimmer was cleaned up and installed in the Spit.

The area of frame in front of the brake disc was discolored with kind of a rust color, I assume from the brake pad dust deposited on it over the years. It took sandpaper and a Scotchbrite pad to get that looking better. The voltage regulator attaches to this same chunk of frame. I removed it and installed a new one, then finished the session by bolting the polished recoil on.

[400brian]

Sunday the 14th I got in the garage and began by installing rubber grommets in the handle bar around the bar warmer wires. The grommets that came with the NOS kit were too hard to use and I had get some off the Jungle website. I finished the bar warmer installation by applying some liquid electrical tape over the fiberglass insulation in the ends of the bar.

I then turned my attention to modifying a bar pad to fit the Spit bar. This was a pad that had come off a Cyclone I think. Many of the attaching studs were twisted off, which made it a good candidate for this project. The spit bar has a different curve in it than the earlier sleds, and is narrower between the grips. I spent quite a lot of time measuring and pondering, but eventually I had to start cutting. I took off a little at a time with a hobby knife, eventually coming up with something that kinda fits. The only way to get it on and off is by sliding the brake grip out to provide the room, so I can't put the rubber hand grips on until I get to the very end.

As I was finishing up for the evening I decided to pull the engine over and check for spark. With the plugs out and sitting where I could see them, I grabbed the rope and gently pulled the engine over just to see how it went before I pulled for effect. The rope stopped dead in just a few inches! Not knowing what was going on, I moved over to the clutch end and carefully rocked the engine back and forth . I was hearing crunching sounds as if I was chopping acorns or walnuts. Not good.

I pulled the heads off and looked in, and saw nothing out of order. I started pulling the flywheel, but I was short one bolt I needed for the puller.

[400brian]

On Monday the 15th, I was back in the garage with the puller hardware I needed, found the flywheel holding tool on the bench, and quickly had the flywheel off. The flywheel housing has a 1/2" hole in it to allow you to time the engine with a timing light. There is supposed to be a plug in it, but I have never had one. It had occurred to me that over the 6 years of sitting on the bench, something could have fallen into the hole, and was the source of my problems. With the flywheel in my hand, I found that was not the case. However, I had sourced a plug to close the hole to that possibility which I then installed.

This left me with the certainty that whatever was making the crunching was coming inside the crankcase. I had put my ear to each bore to try to localize it, but I really couldn't tell. I began by removing the airbox, carb, and the outer half of the intake manifold. As soon os the manifold was open I saw the source of the problem.

[400brian]

On Wednesday my mechanic was out, and we got the cylinders pulled off to see what had been going on in there.

Most of the problem was on the mag side. I was expecting to see cracked corn, instead we had corn meal. Remember, the engine had never even been pulled over vigorously, much less run.

We began by vacuuming the loose stuff out of both sides, that got the bulk of it. I then carefully picked the corn out of the lubrication groove of each connecting rod, then blew everything out with shop air.

Thursday I was in the garage by myself. I used brake kleen to dry the oil out of the case and underside of the piston, and then blew it all out.
I looked everything over closely with an LED penlight to make sure everything was clean. The throws of the crank pretty much completely cover the bearings, so I really couldn't see into them, but then it made it hard for the corn meal to get in there either. I imagine it was just a few kernels that got ground up, but what a mess it made.

I lubricated everything with 2 stroke oil, and carefully slid the jugs back over the pistons. The top ring on these pistons is an "L" ring, and I deem them to be fragile. I successfully got the jugs on with the ring gaps where they were supposed to be, and got the 8 nuts started on the fasteners. The pto side are bolts that go all the way to the underside of the case, the mag side are studs. The difficulty of getting a wrench on the bolt heads on the underside was increased by the engine being installed in the sled and bolted to the plate. But I got all eight started, and the intake manifold installed to line up the cylinders.

[400brian]

On Friday Galen was back out. We tightened up the cylinder hardware, removed the intake manifold, tightened up up the nuts behind it, and re-installed the manifold. With everything in position, we rolled the engine over and felt nor heard anything amiss.

We moved on to dropping the heads on, getting the washers and nuts onto the studs, and then torqueing them to spec. With that complete, we installed the flywheel and recoil.

We were now back to where we were last Sunday; checking for spark. I pulled it over and he reported he saw spark. I shut off the lights and had him pull, and yess there was spark on both sides. Not nearly as impressive as what we see on the Hewtech ignitions, but there was spark.

We closed out the work day by installing the exhaust.

It was a good day!

[400brian]

Saturday June 20th; Galen and I attended a local farm auction. There were 66 tractors for sale, mostly from the 40s and 50s. I bought a couple of old Case's, because I don't have enough junk. We got home early enough to get in the garage and install the las track cleat we had been missing, but had recently received. Galen got under the sled and I handed him the hardware with the Loctite applied.

On Sunday I did the final cleaning on the gas tank. The broken tool box cover had let water stand in the box, which apparently rusted the tools within, which left rust stains in the box. I cleaned the tank inside and out to get it ready for paint.

Monday evening, I had a bit of daylight left to shoot a couple quick coats of Krylon Fusion on the tank. Looks good t o me!