Which HS engine?

[Dr.Ben]

I have a question please.

From all I have read, the classic HS carb is a bowl affair. My particular variant of this engine uses a primer bulb carb and and has a shroud that completely covers the cylinder head. This issue is that I had intended to fit a bit larger bore carb to improve performance a bit, but I do not see how this is possible with this arrangement because the stock carb has a much narrow bolt spacing. The intake manifold plugs into the intake casting on the crankcase and is sealed by what I presume are Viton orings. Do other HS engines simply use a different manifold to accommodate the wider bolt spacing of the bowl carbs, or do those carbs actually screw up to the block itself? I am also not seeing how a performance gain is to be had with the larger carb if its bore is larger than the hole in the intake's casting.

Educate me please or if this has been covered in a thread I missed, please refer me there.

Thanks,
Ben Minor

 

[MotorBicycleRacing]

From all I have read, the classic HS carb is a bowl affair.

My particular variant of this engine uses a primer bulb carb and and has a shroud that completely covers the cylinder head.

Educate me please or if this has been covered in a thread I missed, please refer me there.

Welcome to the forum.

What Hausheng motor do you have?
what is the size of your motor or cc?
where did you buy it from?

Only the 50 cc Huasheng motor uses a butterfly carb.

 

[HeadSmess]

huaheng 50 lf42 or whatever it is, has the bowl carb, and from memory its directly bolted to the head/flange.there may have been a spacer, but the carb clamps it on, not seperately bolted on like most brushcutter type motors.

i made up an adaptor plate to take a standard pitbike/crf50 style carb... not sure if theres any direct bolt on replacements.

if you have the standard pipe bomb muffler... change that before worrying about the carb. they go better when they can exhale easiest way is chop out the 10mm outlet and replace with 5/8 or similar tubing...


now if you have the huasheng copy of the robin/subaru...ie, a 25 or 35cc "brushcutter" type motor, it will have a diaphgram carb. this sounds like what you have with a primer bulb, enclosed in the shroud. in which case, any carb suited to the (small) 4poppers will do the job. starter bolts on with 4 bolts and is square, while the 50cc has a 3 bolt starter that is attached to the shroud/cover

once again, muffler first! if they have the little box bolted onto the cylinder under the shroud, replace it with a straight pipe. let the thing breath and forget about the silly emission/noise level requirements!



was running the 50cc yesterday with no muffler at all. they are surprisingly quiet. can watch the valve going up and down, see the odd flame and spark, and dont need earplugs

straight pipe, aerosol can welded to the end, another pipe welded into the can makes for a pretty good general 4popper muffler and match the port/flange with pipe sizes!

this bit depends on area you intend operating. i live country. i can do such naughty things as straight pipes

you need to give more info when you ask about an engine. each manufacturer makes many varieties, all different. ;

 

[Dr.Ben]

Thanks so much for the kind replies guys. I understand the need for more motor info, but I spent several hours prior to putting up this post researchingwhich HS engine this happens to be because its appearance and intake configuration are inconsistent with any 49 cc HS engine. This engine is for all the world consistent with the brushcutter variant including the butterfly carb and three bolt starter, but HS labels it as a 49cc on the shroud which completely covers the valve cover. I don't know whether they simply bored the jug for a larger piston or not, it is an oddball 49cc variant, or is it simply a case of the Chinese playing loose with the truth on the true displacement of the engine. I will play with the exhaust too. I wish I could find a carb with a bit larger choke area, because this one is choking the engine down. If any of you has a suggestion in this area, I would love to hear your thoughts. Thanks so much! Ben Minor

PS and almost forgot: Could one of you please tell me the bolt spacing of a true 142 49cc on the crank shaft side of the engine that would receive the usual gearbox? I am weighing options for a possible motor swab using my existing gearbox.

huaheng 50 lf42 or whatever it is, has the bowl carb, and from memory its directly bolted to the head/flange.there may have been a spacer, but the carb clamps it on, not seperately bolted on like most brushcutter type motors.

i made up an adaptor plate to take a standard pitbike/crf50 style carb... not sure if theres any direct bolt on replacements.

if you have the standard pipe bomb muffler... change that before worrying about the carb. they go better when they can exhale easiest way is chop out the 10mm outlet and replace with 5/8 or similar tubing...


now if you have the huasheng copy of the robin/subaru...ie, a 25 or 35cc "brushcutter" type motor, it will have a diaphgram carb. this sounds like what you have with a primer bulb, enclosed in the shroud. in which case, any carb suited to the (small) 4poppers will do the job. starter bolts on with 4 bolts and is square, while the 50cc has a 3 bolt starter that is attached to the shroud/cover

once again, muffler first! if they have the little box bolted onto the cylinder under the shroud, replace it with a straight pipe. let the thing breath and forget about the silly emission/noise level requirements!



was running the 50cc yesterday with no muffler at all. they are surprisingly quiet. can watch the valve going up and down, see the odd flame and spark, and dont need earplugs

straight pipe, aerosol can welded to the end, another pipe welded into the can makes for a pretty good general 4popper muffler and match the port/flange with pipe sizes!

this bit depends on area you intend operating. i live country. i can do such naughty things as straight pipes

you need to give more info when you ask about an engine. each manufacturer makes many varieties, all different. ;

 

[HeadSmess]

the 49cc looks NOTHING like a brushcutter.

http://en.hsztgroup.com/en-us/#2


this used to be a good site. i cant navigate it anymore or find the 142f anywhere.

now forget everything ive said cause i see they have 49cc brushcutters, so who knows what you have? a lot more models listed than three years ago!

 

[Dr.Ben]

Yeah, no shi......Now you see why I got so confused when I did the research prior to coming here. Right now the best piece of info I can get would be the mounting dimensions ie the bolt spacing on the crankcase) for gearboxes mounted to the 142 so I can see if my existing one will retrofit to a true 142 or whatever the heck they want to call them now.

Thanks so much.

Ben Minor

 

[dchevygod]

The big 4strokes use the industry standard 76mm shoes and a 78mm drum. I've never needed the bolt spacing measurement sorry but knowing that its the standard pretty much any trans should bolt up. I just helped a friend put a hs142 under a lifted red rider wagon with paddle tires and matching trailer to haul the party supplies up the dunes Top speed 8 mph but with a high hp motor this setup with cart slicks did 32 and did not wait long to get there. The cart and trailer matches his red vw sand rail. Wish I still had pics my HD got wiped.

 

[darwin]

Any pics of this mysterious motor?

 

[dchevygod]

Darwin, Is that at me? ^^