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