Need help reading numbers stamped on vintage mcculloch saws

[Danny Newman]

I need help how to read the numbers, right to left, stamped on bottom of vintage mcculloch chain saws. I have one saw that reads left to right: 74_? (last number looks like a 0 and to the right are the numbers 30 80. Just below that number on the left is 84__? (last number unreadable, also looks like a 0. No number to the right of that one. My 450 chain saw has, right to left, 400 and 450, which I assume is the model number, and the number to the right is 3760. And lastly, I have an old saw motor I have had for several years, and the only number stamped on the bottom is 62481 . I did find out on one site that the 450 is 90.4 cc and 5.5 C.I. , with 2.165 bore and 1.5 stroke. Does anyone know the horsepower of this 450 model? Help with reading the other numbers on the other saws would be greatly appreciated. The 450 is destined for a vintage go kart, and I am not sure if it has enough power for casual riding.

 

[heimannm]

The numbers on the left side are the model numbers. 740 is direct drive and 840 is gear drive version of the same engine (99 cc, 2.165 bore x 1.635 stroke), normally they would strike the model number the saw did not become so if it had a gear box it would be an 840 and the 740 would have been struck through and vice versa.

The numbers on the right are the Serial number, there is no hidden date codes, just sequential Serial numbers.

I have not seen reliable HP numbers for either model but the 740 would be a better choice as a kart engine all things being equal. The 740 is the "Super Series" and shares certain features with the SP105/125 chassis.

62481 is either a 250 or might be a Super 250, the notes I have are not very clear on the point.

Mark

 

[Danny Newman]

The numbers on the left side are the model numbers. 740 is direct drive and 840 is gear drive version of the same engine (99 cc, 2.165 bore x 1.635 stroke), normally they would strike the model number the saw did not become so if it had a gear box it would be an 840 and the 740 would have been struck through and vice versa.

The numbers on the right are the Serial number, there is no hidden date codes, just sequential Serial numbers.

I have not seen reliable HP numbers for either model but the 740 would be a better choice as a kart engine all things being equal. The 740 is the "Super Series" and shares certain features with the SP105/125 chassis.

62481 is either a 250 or might be a Super 250, the notes I have are not very clear on the point.

Mark

Do you know where I might find new rings for the 740? Without taking the piston out, it appears one of rings (the top one) is broken. There is not much compression. The 450 has good compression. I very much appreciate this information.

 

[heimannm]

Start with Bob Johnson, 607 638 9297.

Mark

 

[Danny Newman]

Do you know where I might find new rings for the 740? Without taking the piston out, it appears one of rings (the top one) is broken. There is not much compression. The 450 has good compression. I very much appreciate this information.

Start with Bob Johnson, 607 638 9297.

Mark

Start with Bob Johnson, 607 638 9297.

Mark

Thank you once again. Tear down and cleaning and polishing the 740. If it is the same bore as the 450, I should be able to use a ring out of it for the 740, right??

 

[PogoInTheWoods]

I show two ring sets for the 740 with one matching the 450. Difference is in the ring thickness. That said, if you have the saw torn down, why not put new rings in it just because? 58881 is what I show for the 450 and is standard for the 740 which also came with a thin ring piston assembly. Coupla sets of 58881's on eBay right now for around $20. Bob Johnson may be more reasonable.

 

[Danny Newman]

I show two ring sets for the 740 with one matching the 450. Difference is in the ring thickness. That said, if you have the saw torn down, why not put new rings in it just because? 58881 is what I show for the 450 and is standard for the 740 which also came with a thin ring piston assembly. Coupla sets of 58881's on eBay right now for around $20. Bob Johnson may be more reasonable.

Appreciate the info on the rings. I didn't realize the ring thickness was different on the two saws. I dont have the pistons out yet. Will be checking them out soon.

 

[Opps]

The numbers on the left side are the model numbers. 740 is direct drive and 840 is gear drive version of the same engine (99 cc, 2.165 bore x 1.635 stroke), normally they would strike the model number the saw did not become so if it had a gear box it would be an 840 and the 740 would have been struck through and vice versa.

The numbers on the right are the Serial number, there is no hidden date codes, just sequential Serial numbers.

I have not seen reliable HP numbers for either model but the 740 would be a better choice as a kart engine all things being equal. The 740 is the "Super Series" and shares certain features with the SP105/125 chassis.

62481 is either a 250 or might be a Super 250, the notes I have are not very clear on the point.

Mark

Hey Tree freak can you tell me anything about my Mac 15...Serial number 77771

 

[heimannm]

Not much other than it is surprising McCulloch was able to see so many of them. Seriously detuned 80 cc engines, gravity fuel system, bone shaker grips. At least they look like an early vintage saw.

Mark