Tecumseh, Dellorto, slide carbs, Black Widow

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cfh

Well-Known Member
#41
#41
It appears Massacre is using that 22mm carb too... i thought he was using the 20mm but apparently not.

Actually the intake plate for an HS50 will work fine on an HS40. It just looks weird because of the D shape. If you don't like it, a minute on the bench grinder will take that "hump" off the bottom side and it will look more 'normal' on a HS40. That's all i do to make it work. That and make sure you use a new gasket. I'm using 7/8" stainless for the pipe and it's round. It's not a D shape (obviously) like on the HS50 - the original HS50 Tecumseh intake manifold has a D shape. But it works just fine for either HS40 or HS50 that way.

Has anyone documented the actual Mikuni 22mm jet numbers for a HS40, HS50, stock or modified? I haven't seen any posts about that here...
 
C

cfh

Well-Known Member
#42
#42
you're right though making them other people would be problematic at best. there's too many variables. like on the picture above that's a Powerdyne. and i had to angle the carb towards the PTO just a few degrees so the air cleaner would miss the frame's seat tube. there's a lot of variables... what carb, what motor, what bike, what exhaust, what air cleaner?
 
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cfh

Well-Known Member
#44
#44
Turns out i have a PZ22 carb at the shop. It is the exact same flange size as the 16mm PZ16 that i am using. So i can bolt on the PZ22 and try it out, without any mods to the new intake manifold.

The 22mm throat size is .866". The 7/8" stainless steel tubing i'm using on the new intake manifold has about the same inside diameter. So no problems there.

 
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cfh

Well-Known Member
#46
#46
Massacre that's a weird ebay description. they call it PZ20 which implies 20mm. But it says 22mm in the description. I like that one, the choke is nice. But it's twice the price of the PZ22 i listed. i wonder how much different they are?
 
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cfh

Well-Known Member
#47
#47
tried the PZ22 carb 22mm that was laying around, so installed it on the Powerdyne and gave it a ride today. This is different than the carb Massacre used - this one has a round float bowl and a plastic choke lever. It did work fine, but frankly, i can't really tell any difference between it and the 16mm variant. In fact I think i like the 16mm pz16 carb better on the HS50. The 22mm seems to 'load up' a bit more than the 16mm. but i will play around more with it.

 
massacre

massacre

#48
#48
cfh said:
Massacre that's a weird ebay description. they call it PZ20 which implies 20mm. But it says 22mm in the description. I like that one, the choke is nice. But it's twice the price of the PZ22 i listed. i wonder how much different they are?
Click to expand...
You’re right I never measured the carb to see if it really is 22mm
I usually don’t buy the cheapest stuff on eBay, try to stay middle ground on prices.
 
C

cfh

Well-Known Member
#49
#49
I received two of the 22mm carbs that Massacre was using. They are much better than the round bowl PZ22 carb i tried. The two round float bowl PZ22 carbs didn't like angle, and would leak easily. The PZ22 that Massacre was using has a rectangle float bowl and didn't leak. Also the metal choke lever is a better design. They were like $18 each on ebay.

But after installing it, the motor would run, but nothing more than idle. Now if you put the choke on full, it would run decently. But obviously this is not ideal.

The motor is a Tecumseh HS50 points motor from the late 1970s. It was off a snowblower, so it has a steel flywheel. All stock except for the carb and an open exhaust.

I also bought a jet kit off ebay. The PZ22 main jet does not have any markings. But the jet kit has jets from 85 to 95 in the kit. Just looking at the 85 jet i could see the hole for that jet was larger than the stock PZ22 jet (whatever size that is).

With this in mind, i replaced the PZ22 main just with a #90 main jet and then a #92 main jet. Man did this help! Like a lot. The performance of the motor was better than the fully stock 16mm PZ16 $12 ebay slide carb i was using.

I will say if you don't want to mess with jetting, the stock PZ16 carb is the way to go. But the PZ22 will give a bit more performance on an HS50 motor (but the main jet needs changed.)

Below are pictures of the PZ22 carb i used and the jet kit. Note i did measure the carb, it came in at 21.75mm. So it is a verified 22mm carb.



 
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