340s teardown update

[Sprailfire340]

I've gone through the entire range of emotions in the past few weeks. The excitement of obtaining a raced 340/s, wondering what I have to work with, hoping there is something to work with and dreading there is nothing salvagable. So I dove in last week and started tearing her down. I got the engine removed, but got hung up on a very rusty flywheel. I didn't have the right bolts for my puller and also did not have the appropriate clutch puller. Tonight I solved both those issues and moved onto the heart of the matter. I ran into a little trouble removing the stator assembly, stripped a few of those soft phillips head bolts, but eventually got it removed. Onto the good stuff or so I hoped. Heads look usable. No noticable pitting. Jugs look usable with a light hone. One score I can feel with my nail, but doesn't appear to be too deep. Pistons are another story. 1 might be usable, need to remove and clean up for a closer inspection. The other definitely not. Top is dented in pretty good like a punch of some sort was used to try loosen things up , but I guess I'm not exactly sure what happened. The crank spins freely now that the rusted flywheel has been removed, but it too appears to have a lot of surface rust from what I can see. I was unable to remove the piston pins as they only moved about a 1/4" and then got tight (I removed the cir clips). Any trick to removing stuck pins? Also anyone tell me the significance of the red paint on the inside of the heads or the white dots on each end of both rods? I'm assuming this was part of some inspection, but can anyone confirm? Were different colors used?

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[HoosierDeereMan]

Mitch,

It's a little hard to tell in your picture but I think you have two different heads! I think the head on the left is a 295s and the head on the right is a 340s. You can tell the difference by the taper in the combustion chamber. 295s has a sharp transition into the dome of the head. The 340s is a more gradual rounded taper into the dome of the head. Every 340s head I've seen has that red line. Maybe something from the factory for quick reference? I've attached some pictures for you to compare your heads to. First is a 295s vs. a 340s head. You can see the differences in the taper of the combustion chambers between the two. Second is a close up of the 295s head. Third is of Brian Lindner's 340s crank tore apart at Jerome Kretzman's for rebuild. The rod is stamped K-1. The 340s used a heavier rod than the 295.

Hope this helps.

Troy

[HoosierDeereMan]

295 head close up.

[HoosierDeereMan]

340s crank

[Sprailfire340]

I'm pretty sure the heads are both the same...just a bad pic. That's what I get for dropping the camera one too many times. Upside is the wife got a new one and I got the old one for the garage.

The rods are stamped K-1. My plan is to block up the rods/pistons and use a socket to drive out the pins tonight. Once I get them out the crank is headed to Jerome for inspection. Anyone have a set of pistons they want to part with? or tonight's winning lotto numbers?

[JDT]

You can heat the piston with a heatgun to aid in removing the pin. (just a heat gun, not a torch)

A pin puller is a better tool to use than a socket and hammer.

[Sprailfire340]

I would agree the proper tool is always best, but I don't have one. Do you have a favorite for these sleds or will a universal one like this be fine? http://www.alssnowmobile.com/PRODUCTPAR ... eptid=1005

[JDT]

Looks like the one I have Mitch.
Price is good also.

[Cabindweller]

I made my own Piston pin puller cost me $1.68 down at the hardware. It consists of about 5/16 Carrage bolt 6" long and a 1" pipe 2" long, that and a few washers and a nut. I had to grind the head of the bolt down a little to make shure it was smaller than the piston pin. works both ways too.

Jerry

[ICCSF 108]

You mean that a socket & a hammer isn't the right tool for pin removal? damn I learn'd somethin new today.. Maybe I should purchase one of those or make one like Cabindweller did, those sockets are getting too expensive..

Kenny

[400brian]

At any rate, I think we know why they they retired Mitch's 340/S.

[sledz]

Mitch,
Glad to see you tearing into it so quickly, I'm excited to watch the progress. I have no idea why that one piston is dented like it is, the guy told me the sled ran when he parked it as I asked him specifically. He must have mis-remembered , cause he sure was a nice enough guy.

Steve

[ICCSF 108]

It maybe did run when he parked it, he just failed to tell you they pulled it home or loaded it in the back of a pickup from where he parked it..

Kenny

[lwb140]

mitch , pm me about pistons ,i can fix you up or at least share with you my rescent experience wade

[Sprailfire340]

Thanks to Jerry I made my own pin puller for less than a buck. And Kenny you'll be happy to know I still found a way to use a socket
Crank is out, boxed up, and will be mailed out tomorrow for inspection. Cross your fingers and
Wade you have a pm.

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