HOOT GearBox replacement?

tyrslider · Jan 18, 2009

Yes, sorry I've been soooo busy w/ my website and builds! Here are pics.

I wrote this last night on the other forum: I shimmed up the 8 box Hoot that came originally and will be testing it out in the morning. I'm not so sure that the engineering is the problem so much as the manufacture/assembly is the problem. There was so much slop in the gears that they wobbled, rubbed and wandered. The clutch was mounted improperly, the reduction gear had about 1/4" of lateral travel Keep in mind that they aren't straight cut gears so there is side pressure. the 1:1 gear on the reduction gear shaft had room to wander too. So after shimming up the reduction shaft/gears I shimmed up the clutch to bring it out so that the bell gear was in full engagement w/ the reduction gear and now I believe it is the best it can be. If this works to give reasonable reliability I will manufacture new shafts that won't require much shimming and offer a rebuild kit.

Today: No noisy GB (so that's what the motor sounds like)! Can't say that it will last a long time but it's not noisy. So more riding/testing!

So there's no confusion I'm not talking about the Gearbox below when I mention the 8 box hoot; I was unable to use the box pictured just wanted to show the inside.

NEAT TIMES · Jan 18, 2009

The Box Pictured Is 3:1?? What IS The Hoot Box Ratio?? Thanks Ron

tyrslider · Jan 20, 2009

It's just over 4:1, like 4.1:1. I don't remember exactly; I remember for sure that it's just over 4:1. At 3:1 w/ a 26 in wheel and 12 tooth front 44 tooth rear at 7000 rpm's you get a top speed of 49 mph. The motor doesn't have enough torque for that unless you put it on a road bike and help (pedal) it a lot! @ 4.1:1 w/ 10 tooth front and a 44 rear you get just over 30 mph @ 7000 rpm's. I would like a 40 rear, I think, but I'm willin' to help up hills.

Large Filipino · Jan 20, 2009

milegajo said:
One does wonder that if you could extend that out put shaft and have an extra support you'd have the beginnings of a 4 stroke shifter kit

It looks like you can replace that shaft for a longer one then support it with a bushing to the frame then set it up like Pablo's kit then omg the 3 to 1 gearing wouldn't matter anymore for you can correct it with gearing. But you'll need that freewheel crank but you'll do away with the left sprocket.

That's the million dollar answer.

NEAT TIMES · Jan 20, 2009

I Have A Transmission In My Hand (new Unused) For A Pocket Bike. It Looks The Same As The One Pictured But The Output Shaft Is Shorter (1 Inch In Length). It A Splined Shaft With 17 Tooth Sprocket. The Splined Shaft Is 14mm (.550") Diamiter. The China Girl Kit Chain Is Way To Large The Sprocket Pitch Is .300 In... It Has The 78 Mm Clutch Drum. It Is Chain Drive. You Can Buy Shaft Couplers Of High Quaility. This Box Has 3.25:1 Ratio. If You Extended The Shaft To The Right Side For A Shift Kit Type Setup, The Pedal "crank Sprocket" To Rear Wheel Cassette Would Have To Be Much Much Smaller To Get The Correct Gear Ratio. Of Course You Would Need The Free Wheel And Crank Setup. No Mater How You Try To Build, The Price Adds Up. Has Anybody Ever Checked The Happy Time Crankshaft And Clutch Drum Gear Ratio. The Number Of Teeth On The Crankshaft And On The Clutch Drum?? Ron

vooodooou · Jul 28, 2009

hi all i am new to this forum, so hello. i got one of these kits. sux, sux, sux, even with peddling clutch lasted about a week. way to high gear ratio. it is ether buy a new crank $39 and old type cam cover $10.95 and a old type gearbox $119. or a $89 76 tooth new rear sprocket. plus shipping! the old saying you get what you pay for, and it usually cost more than the best. now on the good side it would make a 20" wheeled bike fly

freewheeling frank · Jul 28, 2009

hey maybe im missing the link here but am very interested how much, and where do i get one?

MotorbikeMike · Jul 28, 2009

Hi Frank, I can't figure out what it is you would like to get? There are many parts available from me, and others.

Mike

vooodooou · Jul 28, 2009

freewheeling frank said:
hey maybe im missing the link here but am very interested how much, and where do i get one?

Hi i got it of ebay about 2 weeks ago. buy now was $239 +54 sh but he has make offer i got min less, still $54 shipping. seller boygofast

i am starting a new thread in "Gear box ratio and final drive ratio vs MPH and MPG. , so maybe we can put are collective heads to together and find out where is the (sweet spot) of these 49cc 4 stroke are. dnut

freewheeling frank · Jul 28, 2009

motorbike mike ,i am looking for a reliable hoot replacement,thanks frank

broHSI · Jul 28, 2009

freewheeling frank said:
motorbike mike ,i am looking for a reliable hoot replacement,thanks frank

if your 4 stroke 50cc HuaSheng motor has an output shaft your only choice for a gearbox is a Grubee for about $120 from bicycle-engines.com
What is the diameter of your motors shaft?
Vooodooou's motor has a centrifigal clutch built into it like a DAX Titian 4 stroke

vooodooou · Jul 28, 2009

hi all here is some pics so we can get on the same page. the clutch sets in side the cam cover. the crank has a taper shaft and no key way. one 10 mm bolt holds the clutch on, the taper starts at 14 mm.

broHSI · Jul 28, 2009

Thanks for the photos

When you bought your kit on ebay from BoyGoFast did you know what gearbox you were getting?
I have looked at his auctions and I could not see any photos of the gearbox except for one of the Hoot gearbox slightly showing behind the HS motor.
BoyGoFast used to sell the Hoot figure 8 box

vooodooou · Jul 29, 2009

hi all
i been scope n out the spec on this transmission, i think i found a new gear for the large one.
this will move the ratio from 3:1 to 4:1. this will make it much more desirable to the (i am going to stick a big honken engine on my bicycle) bunch. we are haven fun now.

broHSI to answer your question. NO lol. I was like you could not see. but i thought it would come with the gears kinda close to what was needed.

but this would be a good kit to put a 142 on a pocket bike, that needed a motor or a mini chopper.

Egor · Aug 3, 2009

Vodo, it looks like the clutch was slipping on the crank shaft? I have noticed that all the sellers that have the chain drive boxes all hide them. I think they are trying to pawn off the junk they got and now can't send back. Are the sprockets the same as the wheel sprockets? there is a lot of room to enlarge the output sprocket. Or the best way to lower the ratio would be at the rear wheel, the 50 tooth sprocket. I would like to try one of those but I would not spend any money for the junk just to give it a try. Have fun, Dave

tyrslider · Aug 4, 2009

They are #25 chain and there are sprockets available if they were smart enough to use 5/8 shaft in the transmission. I just don't see that chain surviving very long especially on a single speed; if it were double strand, maybe .

From the motor to the rear wheel you trade speed for torque; the more you can spread that transition out (w/o adding drag) the easier it is on all of the componants in the drive system. So it doesn't necessarilly work just to change out the final driven sprocket; it will help. The problem is that not enough speed has been traded for torque and the transmission and motor are taking more of the load than is optimal. drn2

Egor · Aug 4, 2009

Slider - I wonder if you could seal up all that mess and put some ATF in there. I think it would then survive. That clutch looked like it needed to run in some lite oil. I ordered two F80 kits today, I am going to stick with them. I do my porting and carb mods and they run like a clock. I got an old Columbia frame also and am going to use it for one of them. Have fun, and keep up the good work. Dave

PS: I think the EZ kit is the only one for the Honda clone.

vooodooou · Aug 5, 2009

Hi all
here is an update. i got a 56 tooth sprocket, makes the ratio 14:1. it still slow off the line but the clutch is not burning any more. i went on a 25 mile ride out through the country side. on a flat its a rocket but if a hill comes in to play better have your speed up or peddle like heck.

I ordered a 12 tooth # 35 sprocket and a 55 tooth raw sprocket. i will go over to a friends shop that has a Bridgeport mill.

that will make ratio 18.3:1 for hills lots of them here. I will post some pics later

tyrslider · Aug 5, 2009

Egor, Your right about price and reliability, however your not going to be able to buy 2 strokes indefinately.

EZ is not the only option my FireBelly Cycles "HardBox" transmission is an option for the honda and the clone. It is (unlike EZ) available w/o the motor/kit for those who already have everything else.

Vooodooou, seems you know already that the 55 tooth won't fit in that box and that #35 is .375" pitch and not .250" like the chain in there now.

What you may not know is that Tsubaki #35 chain is the strongest available and to make sure to use their masterlink (I definately recommend them). Also if you can't seal that chain in lube you're going to need to lube it often because of the high chain speed.

Can't wait to see what you come up w/! Do post pics/results!

vooodooou · Aug 5, 2009

OOOOPSSSS forgot to tell i am changing gear box output freewheel from 12 tooth 415 to 9 tooth no freewheel #35 chain and 55 tooth #35 sprocket on rear wheel. gives me 6.11 reduction. gear box mod not worthy the time and effort.

HOOT GearBox replacement?

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