Hoglet carburetor

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seadragonfoundry

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I will shortly be starting to build a Hoglet V twin to the Randall Cox design. Reading through the plans, the carburetor specified is an OS 10, which has been superceded. Can any one suggest a replacement for this, or another that will do the job? Or perhaps an alternative set of carburetor plans? I have built a number of single cylinder engines but not a multi. One further question, the plans also specify viton o rings for the piston rings. I have not gone down this path before and while I understand that it works I am a bit of a traditionalist, has anyone used conventional piston rings successfully or is this a No No?Thanks for your help
 
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trumpy81

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I will shortly be starting to build a Hoglet V twin to the Randall Cox design. Reading through the plans, the carburetor specified is an OS 10, which has been superceded. Can any one suggest a replacement for this, or another that will do the job? Or perhaps an alternative set of carburetor plans? I have built a number of single cylinder engines but not a multi. One further question, the plans also specify viton o rings for the piston rings. I have not gone down this path before and while I understand that it works I am a bit of a traditionalist, has anyone used conventional piston rings successfully or is this a No No?Thanks for your help
OS 10 refers to it's size in cubic inches (.10 C.I.) OS refers to the maker, so any two stroke RC engine in that size range will yield a suitable carb. You could probably go up to a .15 size carb without any ill effects.

I recall seeing some Thunder Tiger engines in the .12 size range also. They would be suitable as well.

The Viton O-Rings will work quite well. Just be careful you don't have too much 'pinch' in the cylinders, you don't want too much drag. I suspect that cast iron rings would work just as well though, but a lot more work.
 
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Jasonb

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The OS 10ER would be the neearest which is for 12-15 size engines, you can get the carb from the OS 10LA engine but that has a remote needle valve.

Funny that link has it with an enclosed crankcase I drew one up the other day that could be cut from a slice of 5" dia bar.

hog.JPG
 

crankshafter

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I will shortly be starting to build a Hoglet V twin to the Randall Cox design. Reading through the plans, the carburetor specified is an OS 10, which has been superceded. Can any one suggest a replacement for this, or another that will do the job? Or perhaps an alternative set of carburetor plans? I have built a number of single cylinder engines but not a multi. One further question, the plans also specify viton o rings for the piston rings. I have not gone down this path before and while I understand that it works I am a bit of a traditionalist, has anyone used conventional piston rings successfully or is this a No No?Thanks for your help
seadragon.
I have buildt the Hoglet and I made up a carb for it from plans I got from a member on this forum. I do not remember who, but the Hoglet runs and perform wery good whit this carb. From 600 rpm idling to 5000 rpm max:eek:
I would like to build one more Hoglet ang that one will have enclosed crankcase.
BTW I run mine with viton-orings no problems . Never run it for long time so it get to hot. But i thinking of using proper pistonrings for the next one.

Regards CS.
 

crankshafter

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The OS 10ER would be the neearest which is for 12-15 size engines, you can get the carb from the OS 10LA engine but that has a remote needle valve.

Funny that link has it with an enclosed crankcase I drew one up the other day that could be cut from a slice of 5" dia bar.
Hi Jasonb.
Nice drawing of the Hoglet crankcase.
This is exactly what I have in mind when I will build my 2nd Hoglett, but I have not a clue how to draw it. Mybee you .can give some dimesions on this one?:rolleyes:
I am sure many on here would be interested.

Regards CS.
 

seadragonfoundry

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Thank you for your help and advice, amazing what a wealth of knowledge there is in this group.
Thanks
Graeme
 

Jasonb

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The crankcase drawing needs a bit of final tweaking then I'll see what I can do.

J
 

seadragonfoundry

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Have made a start on two Hoglets, this is a fun engine to build. Problem, plans specify Stressproof steel 1144 for the cam. This material is not available in Australia to my knowledge, can anyone suggest a source of supply for a small amount of 1/2" diameter or a suitable alternative ? I have emailed the manufacturer in the USA but received no reply.Thanks
Graeme

image.jpg
 

enfieldbullet

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the stressproof is there probably because it machines nicer than a similar strong steel.

drill rod is probably good enough.

in the cam you definitely want some wear strength.
 

waynes world

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for your carby requirements contact model engines in melb or go to there web site they will fix your carby needs as they are the o.s engines import agents in aus. stress proof yes you should be able to get from smorgon steel they had it in a cattle dog that i had.
 

AndrewW

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seadragon.
I have buildt the Hoglet and I made up a carb for it from plans I got from a member on this forum. I do not remember who, but the Hoglet runs and perform wery good whit this carb. From 600 rpm idling to 5000 rpm max:eek:
I would like to build one more Hoglet ang that one will have enclosed crankcase.
BTW I run mine with viton-orings no problems . Never run it for long time so it get to hot. But i thinking of using proper pistonrings for the next one.

Regards CS.
Hi crankshafter
I realise that this is an old thread but wonder if you could help me. I've just completed a Hoglet but struggling with carburation. I have an OS21 carb but I think it might be too large.
Have you still got the drawings of the carb that you made? If so, could you share them with me?
Cheers
Andrew
 

AndrewW

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Thanks Doc. It looks like you lost some of your footage. Do you have any drawings you can share?
Cheers
Andrew
 

mrehmus

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Here is Randy's HOGLET built on a Harley Sportster frame. Randy built custom motorcycles. This one was rideable.
Screenshot - 8_15_2021 , 12_03_05 PM.jpg

The cylinders are from Briggs and .Stratton off e-Bay. Note the open crankcase and gearbox.
 

mrehmus

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With my memory, I'm glad I remember Randy! Wouldn't let me ride it though.
 

bluejets

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Hi crankshafter
I realise that this is an old thread but wonder if you could help me. I've just completed a Hoglet but struggling with carburation. I have an OS21 carb but I think it might be too large.
Have you still got the drawings of the carb that you made? If so, could you share them with me?
Cheers
Andrew
Looks like Doc's engine has a venturi around 6 to 8mm .
What makes you think the OS21 carby is too large?
 

AndrewW

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Hi
The Hoglet build docs mention a carb with a conventional barrel type throttle 1/4" dia with a venturi bore of 1/8" (circa 3.2mm). I guess that the os21 carb I have has a venturi of 5.4mm, but I can't find any technical spec for it.
The Hoglet has decent compression and I believe valve timing is spot on. Ignition set to 30 degrees btdc, which might be a little too early?
The engine starts well but stops after 15 secs or so. My 'MT44 Part 15' video on YouTube shows it running.
Cheers
Andrew Whale
 
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