Horsepower ratings (125cc motorcycle 33 hp!!! 123 cc chainsaw 8 hp)

[oaktree]

re

Heres a rc aircraft engine thats about 5 lbs at 9.2 hp .... Not bad but pricey !
3W-85xi


rt

 

[oaktree]

re

These are some of the highest quality model aircraft engines .... wrong for application ,but interesting engineering .. Lightest weight to power is what there after .

pic

 

[Guido Salvage]

besides, who the hell want's knobbies on their chainsaw??

Good point, but they work pretty well on the wood hauling wagon...

 

[trappermike]

A lot of the Suzuki's were "square",54x54mm. Weimedog I had a TC125 too,my dad bought 3 new ones,I bought the Suzuki race kit for it,basically a TM125 motor parts,it had piston,cylinder,head,bigger carb and intake and air filter assy,pipe,front sprocket and small oil tank. All for $100 new from the dealer!
Saws use a really "oversquare" motor with a short stroke to reduce piston speed,allowing higher max. revs and allowing them to run at high speeds for a long time.
As has been said here saws gotta be very light so have to be a pretty simple design.

 

[rwoods]

FWIW there is a 1974 Alsport TS-101 (A little McCulloch101D powered tricycle) with some manufacturer's literature for sale on eBay. The literature rates the mufflered 101D at 14 hp which pretty much squares with the experimental aircraft rating of 15hp for the MAC 101B. Ron

 

[Team FAST]

I echo the comments on kart engines. Former kart racer here too. On my roadracing 125cc shifter kart, we were seeing 43hp on the dyno at 13,000

On my 250cc superkart with a highly modified CR-250, we were over 60hp and quickly approaching 65hp on the dyno at about 11,000 rpm

Both engines are watercooled. The other significant benefit that my kart engines had over a saw engine is a digital fully programmable ignition which is HUGE. And one other thing kart engines get is a real carburetor with a slide valve....massive amounts of air at WOT.