Mcculloch 797, Super 797 thread

[Bigmac]

I have added washers, I get gold grade 8 for a metric application, they are smaller O.d.

And sometimes hardened machine washers, they are thicker and don’t deform.

 

[B Royals]

Quick update. Christmas came early. I received my block and new piston from Terry today. Mark has a package in the mail for me. The 090 carb should be here shortly. I need to order one more seal for the Flywheel side of the crank, a little confusion between Terry and I. I have a question for you guys about the crank bearings Terry sent me. From everything I've read, the crank bearings need to open on both sides and most people pick the seal out once installed. These have a metal seal on the side, and I don't see a easy way to pick it out. Any suggestions?

 

[hacskaroly]

These have a metal seal on the side, and I don't see a easy way to pick it out. Any suggestions?

I think Mark @heimannm may have an answer for this (not sure if he is still traveling or back yet). If I remember correctly from a previous post he made, I think he drills a small hole and then screws in a sheet metal screw far enough in that he can then leverage the the metal part out. You might be able to search it, I think is was a post in the McCulloch thread sometime between Dec 2024 - February 2025 possibly.

 

[Woodslasher]

I use a wee little screwdriver and a few love taps when I pop them out. Just dig a corner of the blade into the seam by the inner race and you can pop them out.

 

[heimannm]

That is a "shield" and not really a seal. I don't think it would hurt anything to leave it in place (position the shield towards the outside) but as Dan noted, they will just pop out.

I use the drill and slide hammer with a sheet metal screw to remove seals when the steel housing is large enough like the 61618 seal on the 10 Series.

.



Mark

 

[B Royals]

I have a chain question for you guys. My S797 came with a 36"(40" total length) guide bar, but no chain. It has a 7 pin .404 rim sprocket on it. Do I need a 108DL chain for this application?

I see west coast saw sells some Oregon .404 chain (68JX). Do you guys have any recommendations for chain purchase?

Edit: I forgot to mention I can't find a marking one on the bar.

 

[Bigmac]

I have a chain question for you guys. My S797 came with a 36"(40" total length) guide bar, but no chain. It has a 7 pin .404 rim sprocket on it. Do I need a 108DL chain for this application?

I see west coast saw sells some Oregon .404 chain (68JX). Do you guys have any recommendations for chain purchase?

My cannon roller nose takes a 108,i it’s 40” overall. I hate .404 skip round file chisel, square ground skip is fine. The round file chisel is too rough, especially on a rigid chassis. Semi skip or fill comp are fine for me, I like 3/8 skip with an 8 pin too, it’s smoother.

Even the sp chassis with skip .404 round chisel is a bit rough for my liking

 

[B Royals]

I went to install my crankshaft and bearings into the side cover today, and it's not a press fit anymore. It's not sloppy per se, but not press fit. I was reading on some of the karting pages about using Loctite 609 and drilling a hole for a set screw on the bearing.

Is this a reliable fix? Do you guys have a go to fix for this problem?

 

[heimannm]

The bearings are not a press fit per se in the housing, they are pressed onto the crankshaft. They slide into the crankcase when the engine is assembled.





Mark

 

[B Royals]

I thought I'd check-in with a little progress update for everyone. Slowly but surely it is going back together. I used a bulkhead fitting from McMaster-Carr with a rubber sealing washer I found at Ace hardware, coated with Seal-all. I'm using 1/4" gas line as the 090 carburetor, the bulkhead fitting and the Stihl filter I found are all 1/4". Is there such a thing as too big on the fuel line? The factory molded line seems tiny.

 

[Bigmac]

I thought I'd check-in with a little progress update for everyone. Slowly but surely it is going back together. I used a bulkhead fitting from McMaster-Carr with a rubber sealing washer I found at Ace hardware, coated with Seal-all. I'm using 1/4" gas line as the 090 carburetor, the bulkhead fitting and the Stihl filter I found are all 1/4". Is there such a thing as too big on the fuel line? The factory molded line seems tiny. View attachment 483218View attachment 483220View attachment 483221View attachment 483222View attachment 483223

I don’t think it’ll be a problem having a larger fuel line, the only problem I’ve had with larger fuel line is it’s a little stiffer and doesn’t want to drop to the bottom of the tank and conform to direction changes. And it might take a little longer for it to pick up fuel in the larger line, but could be wrong too.
You might have to have a pretty heavy filter. Did you open up the opening in the tank to match your larger carb there is a small mismatch usually..

 

[B Royals]

I don’t think it’ll be a problem having a larger fuel line, the only problem I’ve had with larger fuel line is it’s a little stiffer and doesn’t want to drop to the bottom of the tank and conform to direction changes. And it might take a little longer for it to pick up fuel in the larger line, but could be wrong too.
You might have to have a pretty heavy filter. Did you open up the opening in the tank to match your larger carb there is a small mismatch usually..

I did as exactly as you discussed in an earlier post. I port matched the carburetor and gasket, as well as a touch of grinding on the reed plate, with the larger reed. I believe the reed plate work was well worth the time, I didn't hog it way out, I just tried to shape it for better air flow.

Jeff

 

[Bigmac]

I did as exactly as you discussed in an earlier post. I port matched the carburetor and gasket, as well as a touch of grinding on the reed plate, with the larger reed. I believe the reed plate work was well worth the time, I didn't hog it way out, I just tried to shape it for better air flow.

Jeff

Awesome! Should make a great runner

 

[B Royals]

Hello everyone. I have my saw all assembled except for the clutch assembly. I don't know if my stack-up is correct, and was hoping you guys could help me. I have the oregon 10624 clutch drum with replaceable floating sprocket. Starting at the inside, I have the felt washer, a big thick steel washer, the clutch drum and sprocket, spring, clutch and nut. It doesn't seem to pull up tight enough for the clutch to have a nice fit on the crankshaft. I've noticed on some instruction packets when replacing the fixed spur type drum that you change the washer/shim setup. Does this appear correct? I haven't torqued it down yet, because I'm not sure it's right. If you guys tell me it's right, I'll run with it and give it a try.

 

[hacskaroly]

Here is a snapshot of the IPL for your reference, looks like you have the correct order, attached is also the full IPL for the saw incase you don't already have it:

 

[heimannm]

Your arrangement seems correct and does match what the IPL shows. Make sure the key is fully seated in the crankshaft and that any burrs have been filed down so that the clutch slips on easily. Also, be sure to torque the nut correctly, too many of those clutches and crankshafts have been destroyed by being too loose or too tight.

Documents say 265-325 In/#

Mark

 

[B Royals]

I completely finished the saw today. I primed it up, and it fired off for about 5 seconds and died. I couldn't get it to restart after that. I pulled the plug multiple times and it didn't appear flooded. Tried two different spark plugs to no avail. While I had the plugs pulled I verified if I had spark or not. I have an intermittent spark issue I believe. Bummed out, but got one heck of a workout today.

Jeff

 

[heimannm]

I would start by pulling the flywheel, cleaning the points again, and rechecking the gap. The spec's call for .020" but I target 0.018 just to be on the safe side.

Also, make sure the points can open and close as the crankshaft rotates. I had a D-44 with the points terminal nut so tight the spring could no longer close the points reliably and repeatedly. I spent a few hours chasing that one.

It is also possible that the plug wire or connector (in the boot) are making intermittent contact. Check continuity while moving the wire around.

Mark

 

[B Royals]

It's alive! I pulled the flywheel off, and the timing had went retarded somehow. Re-set the timing and it fired right off. It sounds really good to me. I think I may have an air leak though. I set the high and low adjustment screws at 1.5 turns out to get started on the 090 carburetor. The idle didn't want to settle in for me, and if I even breathed on the low screw to the rich side, it would die. It's getting there.

 

[Lee H]

Definitely reclean your points even if they are new. New points i clean with 1200 grit sand paper then rub clean white paper through them.