Building a SP125C / 101B Kart Saw
- Thread starter blsnelling
- Start date
Help Support Arborist Forum:
I've looked at those, but it would point straight back at the operator.
nmurph
ArboristSite.com Sponsor
- Joined
- Nov 26, 2007
- Messages
- 16,162
- Reaction score
- 7,167
That thing doesn't even sound like mac until it idles down when he is switching it off.
Not only that, but those help narrow the powerband. If you want a wider torque range, then get the full boxed-in muffler or the round steel muffler.
cpr
Addicted to ArboristSite
JJ, so I understand it, is that because the megaphone acts as the diffuser cone on a pipe, sucking exhaust out and charge in, but without the convergence cone to reflect the pressure wave that pushes the new charge back to the cumbustion chamber? Is this the net effect of raising the exhaust port relative to transfers "leaking" useful new charge before the compressing piston can close the port?
The same seller sold a siezed 101B for $750. Now that is a bit much......
eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices
Last edited:
Somewhat. It's a very crude diffuser in that sense. I don't think it's quite the same effect as raising the exhaust too high. I've never used one of those cones, but all the old-time kart guys that I trust have said that those cones make a narrow window of power and that they're only good high RPM and the motors have less torque, even with a stock block.
I don't know what the hell is wrong with these people. Stock 101 parts are not that hard to find. McCulloch made literally millions of these engines.
Merry Christmas to me, and thank you Dr Ives!
One new piston, new rings for both, new rod bolts, gaskets, seals, crank bearings, rod bearing needles, and head bolts.
The remaining defects aren't high enough to be an issue and shouldn't affect performance at all. They're well below the top of the exhaust port. I'm sure glad I sent this block to Terry for a professional opnion before declaring it dead!
It only took .056" to clean it up.
One new piston, new rings for both, new rod bolts, gaskets, seals, crank bearings, rod bearing needles, and head bolts.
The remaining defects aren't high enough to be an issue and shouldn't affect performance at all. They're well below the top of the exhaust port. I'm sure glad I sent this block to Terry for a professional opnion before declaring it dead!
It only took .056" to clean it up.
Last edited:
Here you can see the differences between my block and this other 101 saw I'm working on.
The exhaust was not raised as thought, just hacked on a little with a file. I'll clean it up before assembly.
You can see how much thinner the liner is on mine. One is .010" over and mine .056".
The exhaust was not raised as thought, just hacked on a little with a file. I'll clean it up before assembly.
You can see how much thinner the liner is on mine. One is .010" over and mine .056".
Brian13
Addicted to ArboristSite
Looks great!! Now get to work
.
.
MechanicMatt
Cut Split Stack Burn
Brad, My buddy I work for at night got a speed boat with a Big Block chevy 454 we punched it .030 on the last rebuild brought it up to 468 there is NO replacement for displacement, get that saw running already!
Looks good Brad. By the way, does Mr Ives sell other parts for karting engines besides those being built for saws?
Lookin good Brad.
Looks like Terry took good care of ya.
Lee
Looks like Terry took good care of ya.
Lee
RiverRat2
Serio Tree Freak
Looking really nice brad...
Yeah that narrow power band was described by some of the oldtimers I Motocrossed with as (Pipey) that would make it a dog on lowend coming out of corners not very desirable,,, with a saw for racing I suppose it would require a very light hand and keep the RPM up to stay in the power band???
Yeah that narrow power band was described by some of the oldtimers I Motocrossed with as (Pipey) that would make it a dog on lowend coming out of corners not very desirable,,, with a saw for racing I suppose it would require a very light hand and keep the RPM up to stay in the power band???
Last edited:
I'll have to figure out what I've got now.
Bore 2.28" + .056" = 2.336"
Stroke = 1.835"
Displacement = 7.87 CI = 129cc
Last edited:
Dennis Cahoon
Addicted to ArboristSite
Terry Ives works on racing go karts. His love is racing karts and teaching others about them. He has tons of stuff. He only does the saws because they are the same as his vintage engines for the karts. I have been to his shop and he has been to my saw competitions but I think only to see the kart motors run and as a courtesy to us who have had him work on our stuff. He is a real old school gentleman and good to know. Mike
parrisw
Tree Freak
Sounds like a really good guy. Its a shame there are fewer and fewer of them around these days. Its pretty cool to hear that he enjoys sharing and teaching others about what he does, otherwise it would be lost forever.
There's a few of the kart good old boys around that are good engine builders. Terry of course is a legend, Vince Hughes down in Oceanside is another really good one. He's bored a couple of engines for me and does really amazing work. Another legendary character was Jimmy Yamane. He worked at McCulloch motors and was part of McCulloch's original kart engine design team. Jimmy had some pictures of one of his first karts that had two 790 chainsaw engines on it that he was beating the Homelites with.
