What is a maxi hi torque head, really?

roots to wings /

Dicken around with my 79 maxi hi torque 2hp and in reviewing the engine specs it looks like all hi torques came with 12mm bing carbs and 14 mm round intakes. Wondering why they never put 14mm carbs in these. I have noticed the hi torque motors have a little better acceleration (almost 2 speeding) but wondering if I can use a bigger carb with the stock hi torque head and if I can keep the hi torque head if I choose to kit it (airsal 65)? Thanks

Re: What is a maxi hi torque head, really?

The smaller the carb the quicker the response thus instantaneous torque down low...anyways you can put a 14 on there and read the reviews off treats sounds like stock head works, might wanna mess with squish.

Re: What is a maxi hi torque head, really?

Yeah the stock head is ok on the airsal 65, but the fins don't match, that kit matches fins to the 'old style' head

Re: What is a maxi hi torque head, really?

roots to wings /

closing the thread. someone on another forum gave me this answer, which is similar to one i found here, but more detailed. very helpful. "...so in carburetors there’s big key called velocity and when you go bigger in carb size you lose velocity unless carb is of appropriate size. Bigger carb is better for reaching higher Rpms being stock carb is limiting factor. Considering high torque cylinder is low rev it’s better setup with small carb better velocity and considering high torque makes power down low rpms it better suits a curcuit which is low rpm torque pipe"

Re: What is a maxi hi torque head, really?

Thats dumb, they just put a smaller carb on it because they can only go 30 mph by law and the high torque don't need bigger carbs to go that fast.

Re: What is a maxi hi torque head, really?

Overpriced Parts /

> Graham Motzing Wrote:

> -------------------------------------------------------

> Thats dumb, they just put a smaller carb on it because they can only go

> 30 mph by law and the high torque don't need bigger carbs to go that

> fast.

Ya it made more power and speed with a 14mm bing so they just kept the 14 mm intake and put a smaller 12mm carburetor on it to keep the power down

Re: What is a maxi hi torque head, really?

roots to wings /

Thanks Graham. So has nothing to do with velocity or the guy was right?

Re: What is a maxi hi torque head, really?

Ah I mean technically sorta right? But the difference between 12 and 14 mm really isn't going to have any significant negative impact. You will need to swap around some tuning parts possibly.

Most people that fuck up bings swap them around and have mismatch tuning parts, they run like crap, and they say things like putting a 14 on a 12 hurts the midrange when it's really just tuned wrong.

I have a perfectly tuned airsal with a 14 Bing at home, I have been meaning to pull it apart and see what's in it, next chance I get I'll try to remember to write it down for ya.

Re: What is a maxi hi torque head, really?

roots to wings /

77 e50 65 cc airsal 15mm bing 15 intake 2.17, 24 slide, 78 jet 14x40 gearing estoril/mesh runs awesome even if it occasionally shits the bed at wot

mystery 70 something stock e50 hi torque with bing 14, grandpa 15 intake, 2.22, 24, 72 jet 16x52, techno circuit/mesh gearing also runs the balls

The 79 e50 hi torque i am playing with now has a bing 12, bing 14 intake, 2.22, 24, 57 jet, 16x45, mlm cali/mesh runs good and thinking to put a 1/14/152 on it but not sure if I have to have an 11 slide or if I can use a 24 and not sure if i'd be better off replacing the hi torque head with a stock e50 head when i put the 65cc airsal on it. Thanks for your continued great advice Graham. Big help.

Re: What is a maxi hi torque head, really?

My setup is:

E50

44mm (65cc) airsal, not case matched or ported

Bing 14

2.17 atomizer

2 ring needle

Second notch from the bottom

51 slide

68 jet

Stock air cleaner derestricted

15deg BTDC timing

Proma GP shortened 3"

16*40 gears

I think I'm going to drop the needle one clip, or maybe go back to a 70 and drop the needle 2 clicks once I advance the timing this spring, it's really close, 99% of Moped riders would say perfect but there is just a tiny little spot where I'm not happy with it, and I know it will pick up a little more speed at 17-19 deg btdc.

Top speed right now is just shy of 45 but it pulls even a biggish hill at 35+ looks stock, nice and quiet, the kind of bike I would let my 65 year old mom ride. I think it will be over 45 and might go back to a 15 front just to help it pop out of the hole a little better and lock the clutch faster.

Re: What is a maxi hi torque head, really?

How far do you go to derestrict the stock maxi airbox?

Re: What is a maxi hi torque head, really?

no groms no blasters /

it's a head that lets you tighten the nuts and studs to 12 foot-pounds instead of 8 so that you don't have as many air leaks

Re: What is a maxi hi torque head, really?

> Mike Boyd Wrote:

> -------------------------------------------------------

> How far do you go to derestrict the stock maxi airbox?

Ahh knew I had a pic somewhere.

IMG_20190201_235112.jpg

Cut it open at the seam with a utility knife, took out the 'filter', got rid of snorkel and all the plugs and junk, and cut the hole where it goes into the frame out to about 1".

I like how quiet they are with the air intake routed in the frame, plus you can ride in a downpour, and your jetting stays more consistent.

Speaking of the original content of this thread... This was on a sport mk2 with the "22" dykes ring cylinder. Fastest stock moped Puch made, look at how much they had to restrict it with the black washer in the snorkel just to get it to stay under 30 mph!

Re: What is a maxi hi torque head, really?

roots to wings /

My e50 airsal is single embossed needle clipped third down from top. Not sure if I am getting past 40 as speedo doesnt go past 40 but with the mesh filter and 14x40 gearing it is screaming loud, especially when I lay off the throttle (i am guessing bearings and seals). I can accelerate up big hills. Need to tune clutch to be able to get off the line with 16x40 and expect better top end but 40 is more than fine really. I like the sound of the mesh filter but I like what you did with the stock airbox. I would like to quiet my bike down a bit and not lose anything. how did you decide on the 2.17 for the 14 as opposed to the 2.22? Is there any difference between a 1/14/152 and 1/14/160 other than when they were made?

Re: What is a maxi hi torque head, really?

Ahh yeah good questions my man. I don't mind helping since I can see your brain is working.

The best resource for bing carbs is https://myronsmopeds.com/category/bing-menu/

If you go down below you can see the different numbers (1/14/152, etc) and what guts came in them. The combo there I posted is just something I've found runs well, the 51 slide has the 'buddy hole' which you can add to any slide, it helps out idle better and gives it a little punch out of the hole when you crack the throttle open.

Myron's really explains it better than I can, Ken posts really good stuff about Bing tuning too but it's always incoherent and one size fits all. I have a recipe that works pretty good on mild PP kits and ported stock, is it the best? I dunno but it runs really good on this kit and like 70 kstar type stuff and ported stock. I would be into trying a different setup but this is just what I happened to stumble onto and I've had the same setup on a few bikes and it usually runs pretty good.

You can always go back to the stock posted combo and modify from there but the air filter makes such a big difference that it's tough to use any of the stock settings on a kitted bike with a performance filter. You can also see what atomizers and needles were originally fitted together as a rough guide.

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