Power products AH47 kart engine

[loneagle]

I just picked one of these up. Does anyone know where to get parts for these? Also what is the power band on the little motor?

 

[Russ2251]

Originally a chainsaw engine. Mid '50's (?). 3½ HP. Perfect for mini bike.
Try Ebay. May get lucky and find some NOS parts from somebodies inventory clean out.
Am curious as to part # on carb, located on carb flange.
Does it run?
Can you post close-up pic of engine name plate?

 

[loneagle]

Thanks Russ! I'm a sucker for these little engines! I don't have it in my possession yet. When I do, I'll get some pics along with the carb info. It's supposed to run. I'd like to take it apart and inspect it, maybe some new rings, etc. What do you guess the RPM would be?

 

[Russ2251]

What do you guess the RPM would be?

Can't guess, but higher than so called 'multi-purpose' engines. Were known to outperform equivalent Mac's.
I had an engine similar to this but was 4½ hp.
Got it brand new for $12.00 back around '67 or '68.
Seems the shop owner couldn't sell it as 4 cycles were starting to overtake the 2 cycle market.
I've been hooked on 2 cycles ever since. I am not a 'crowd follower' and refuse (for the most part) to deal with the weight of 4 cycle 'anchors'.
The 4 cycle guys in this forum don't know what their missing.
Sorry for rambling.

 

[sayre315]

thats awsome

 

[loneagle]

Russ, Keep on rambling, I enjoy what you have to say!

Well, I looks like that motor will be going on the minibike. I ended up losing the minibike engine a few minutes ago. I believe the con rod let go. Looks like they don't handle the RPMs too well after all. My son is going to tear it down when it cools off. Oh well!

 

[2or3wheels]

what engine did you bloe clone? briggs?

 

[loneagle]

Tecumseh 2 cycle. I shouldn't have removed that governor!
Here's a few pics-

 

[jr dragster T]

Is that a bent crank or is it made that funny looking way?

 

[Jerryburger]

WOW! So you CAN detonate a Tecumseh 2 cycle! (Oops!) Hopefully you son's okay. Sometimes those guys will lock-up solid, causing an unexpected skid.

 

[Russ2251]

What is drive ratio? Sprocket, clutch and tire size?
What brand oil and what mix ratio are you using?
If known, what is history of engine?

 

[kibble]

OH DANG!!!

 

[jr dragster T]

Looks almost like a goner...Not as bad as my carnage photo's!

 

[loneagle]

What is drive ratio? Sprocket, clutch and tire size?
What brand oil and what mix ratio are you using?
If known, what is history of engine?

The engine let go when I was adjusting the high speed mixture on the stand. Not under load. It was returning down to idle when it broke.

15 tooth PTO
16 jackshaft in
13 clutch out
72 rear sprocket
11" tall tire

I'm using Maxima Castor 927 mixed at 30-1

I can't tell if the crank is bent just by looking at it. It may be because the engine had quite a bit of vibration at idle. More than I remember for a 2 cycle.

I have no idea on the engines history. I got it on ebay!

 

[Russ2251]

The engine let go when I was adjusting the high speed mixture on the stand. Not under load.

This is probably reason for failure.
I always do my high speed adjustments with load and a fully warmed up engine.
Loads tend to smooth out combustion pulses.
I purposely set high speed needle rich then test drive on kart/bike.
If starts to four cycle at WOT, I stop and lean high speed screw by ⅛ turn or less. May take several attempts to get final adjustment correct.
You'll know if you've gone too lean if engine sounds like it's losing power/rpm at WOT.
Better slightly rich than anything lean.
Check plug insulator for light chocolate color.

 

[kibble]

Looks almost like a goner...Not as bad as my carnage photo's!

Almost? I think it is. Look at the damage on the piston, I bet the cylinder got dinged in a few places.

 

[jr dragster T]

And If I remember correcly I was the one that told you not to rev a engine on a stand.

 

[Russ2251]

This caught my attention:

 

[jr dragster T]

Was that one of his engine picture's russ before it blew up?

 

[Russ2251]

No. I just cropped and re-sized his pic.
Extreme right of 2nd pic.
Engine would not run if this was pre-existing hole.