KC's new 4-stroke Jackshaft base

[ajoh]

wow so glad you did this I just bought the jackshaft kit and the HD freewheel from SBP. And a decent hard tail MB with disk brakes. Looking for the right priced and compatible engine kit. I want the 4g but haven't seen anybody ells put all these components together. So does the SBP jackshaft not bolt directly to the 4g, or does it?

Also where is the best place to buy the engine kit? BlowbyU? (is the Honda he sells really worth $300+ more, meaning is it really that much more quieter? quiet is really important to me)

O and how many gears do you have and how fast can it go?

NO the honda isn't worth the extra you'll pay for it Hua Sheng engine (or HS engine) will be more than good enough some guys here have 10,000 miles
on HS engines an still going strong

as for where to buy i've been dealing with http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html
these people an they've been awesome to deal with an i'm all the way in australia! my orders always turn up within 2weeks normally just over 7days

i tried dealing with gasbike first as the first engine i got is a tapered shaft model
but got nothing but the run around an the tapered shaft 4g is never in stock so i gave up on them an deal with bicycle-engines who as i said are awesome to deal with

ps, the motors from bicycle-engines are 5/8 shaft hence yes i ordered full kits from them (my tapered shaft engine collects dust atm)

 

[KCvale]

As for where to buy i've been dealing with http://www.bicycle-engines.com/49cc-4G-T-Belt-Drive-Complete-Gas-Powered-Engine-Kit.html
these people an they've been awesome to deal with an i'm all the way in australia! my orders always turn up within 2weeks normally just over 7days

i tried dealing with gasbike first as the first engine i got is a tapered shaft model
but got nothing but the run around an the tapered shaft 4g is never in stock so i gave up on them an deal with bicycle-engines who as i said are awesome to deal with

ps, the motors from bicycle-engines are 5/8 shaft hence yes i ordered full kits from them (my tapered shaft engine collects dust atm)

There are multiple flavors of the 4G T-belt drive...

The first issue is the engines centrifugal clutch.

The HS 142F 4-stroke engines with the tapered shaft has a good CC on it so the 4G does not contain one, the 5/8" straight shafts require a CC and according to Don they are not as good as the HS OEM one.

The two 4G mount types are not compatible.

The next trick is knowing the belt gearing and where the freewheel is.
Note that T indicates Teeth on a pulley or sprocket, and TFW indicates Teeth on a FREE-WHEELING pulley or sprocket.

Personally I used the 20T/80TFW/9T 4G the most, the smaller 80TFW pulley means a smaller cover and better pedal clearance and simple 9T sprocket output but not a lot of gear reduction.

The 20T/100T/12TFW 4G offers more gear reduction but the freewheel is in the output sprocket.

I have seen a couple of those 12TFW's fail and you can just give them a couple spot welds at the seam to make them work, the downside to that when you just pedal you have to pull the whole drive train to the CC on the engine.

I have not seen a 80TFW fail yet but it wouldn't be as easy to temp fix.

Now for the monkey wrench's...
Everything is changing again and there is a new player.

There is a Grube 4G knock-off gasbike is selling called the Ghost Racer 7G.
Looks to be 20t/100t/12TFW for the straight shaft HF with a slightly different mount base and no clue as to what the actual output shaft is or what CC it ships with.

There is a recent topic here about that somewhere.

The improvement I am looking forward to is the new 4G KCK.

18T/100TFW/whatever you want on a keyed 14mm straight shaft, standard options are a 9T or 10T, but you can opt to use a coupler and shaft to extend the drive to a second carrier bearing to eliminate the jackshaft itself all together like my above pic and it's chain and tie straight into the pedal system with enough gear reduction to work.

When that will be available I don't know, Don needs an MOQ of 500 to justify tooling.

 

[ajoh]

an since you quoted me KC what were you getting at? what was your point?

btw it would be nice if people (I) could actually get hold of the tapered shaft
model 4G drive instead of the only place that i know of the sells them always
being OUT OF STOCK!

this is why i went for the 5/8 kit an my tapered shaft motor collects dust for now...

 

[KCvale]

an since you quoted me KC what were you getting at? what was your point?

Just more information on the new drives comings and what they will bolt on to allow loosing one gear and one chain to jackshaft a 4-stroke direct from the 4G output.

btw it would be nice if people (I) could actually get hold of the tapered shaft
model 4G drive instead of the only place that i know of the sells them always
being OUT OF STOCK!

this is why i went for the 5/8 kit an my tapered shaft motor collects dust for now...

I got mine from gasbike too so I don't know who has any.

 

[ajoh]

I got mine from gasbike too so I don't know who has any.

well why don't you become a 4g dealer then? because i'm sure there is many, many people with tapered shaft engine who want the 4g drive but just can't get
them because of so called "businesses" like gasbike whom are out of stock more often than not ie, that's bad business.

who knows KC maybe you could pick up on others (gasbike) slack an maybe make a little extra coin (just don't be like most australian businesses are an work greed into your business plan)

 

[WAYAFRO]

well I went with the HS and got it done. It's not pretty anymore after riding for two months with no fenders in the salt water mix we got here in MN. Just got my fenders in yesterday. Wish I would have just waited till I got them but I only get around on bikes or bus. I had to fab the BB I got from sick bike parts because I have a fat tire bike and it's 100mm BB. I cut it in half and stuck a pipe over the ends on the inside. Then drilled and roll pinned. Then the jackshaft wasn't long enough so I put the big 48tooth on the inside and the 30 on the outside. Then the gear ratio was a bit to high because the OD of the 26"x4" tires are like 29" so (since for some reason SBP gave me a 9tooth on the right side of the jackshaft already instead of the usual 10), I got the 24tooth put on and now I can be in 5th even goin up slight hills. With 6th and 7th for down hills and when I add all the performance parts on the HS the gearing should still be good. O and a few days ago the cheep throttle broke and I just got a atv thumb throttle with two brake pullers that lock and a brake light switch. (for when I get lights) This makes it a lot easier to throttle and shift.

 

[KCvale]

well why don't you become a 4g dealer then? because i'm sure there is many, many people with tapered shaft engine who want the 4g drive but just can't get them because of so called "businesses" like gasbike whom are out of stock more often than not ie, that's bad business.

who knows KC maybe you could pick up on others (gasbike) slack an maybe make a little extra coin (just don't be like most australian businesses are an work greed into your business plan)

I don't have $40K to get them made and shipped, nor do I have room to stock 200 units, the minimum order.

Nice bike Wayafro, did you get that new?
I didn't think those old Stage III gear drive transfer cases were still around.
Beware the oil level!
It needs just enough oil to splash the gears but not get into the clutch.
It's like 10w oil, like 3in1 oil or lubricating hydraulic jack oil.

Another tip is move your shifter to the left side, it's upside down but the brake handles reach over the shifter and the throttle better.

One last tip is keeping the right side JS chain tight, you can make a tensioner out of an old derailleur sprocket, scrap metal and a spring.

Just tips, take 'em or leave 'em ;-}

 

[xlander]

That coupler with the blue rubber teeth. That is a common forklift part. I believe Raymond forklifts should have that readily available.

Very cool looking set up.

Would you mind a complete parts set up... freewheel forward cassette and where to find the stuff? Is this something your building up to sell?

 

[KCvale]

That coupler with the blue rubber teeth. That is a common forklift part. I believe Raymond forklifts should have that readily available.

Very cool looking set up.

Thanks xlander, and the exact coupler parts I used are in the first couple of posts.

Would you mind a complete parts set up...
freewheel forward cassette and where to find the stuff?
Is this something your building up to sell?

Yes. A new design for production through Don Grube (Grubee) based on the freewheel belt drive 4G.

It is in the specs as the KCK and Don says the whole G thing is too funny and will call it the 10G hehehe.

Anyway, it's ~35K to gear up and run 200, the price drops after that, but I don't have that kind of money.

It's a cool design though, and with the output shaft and base mount changes it should be a simple drop in 4-stroke right side output engine unit.

 

[WAYAFRO]

Yah I got the motor and gearbox as a set.
I was real careful to follow all the instructions that came with it.
To the point where I was looking all over for the "machine oil" they called it. haha
I was thinking do they mean High temp machining oil for when your milling ect.
I ended up putting the same oil I got for the engine in there. 10w high performance synthetic motorcycle oil. Lucus like $20 a quart.
But I put exactly the amount they called for. It was only like 1 once.
I've been thinking about how I'm going to check it. I don't see any leeks so I should almost never have to replace right? maybe once a year.

And yah haha with the clutch lever. Because of the beast handle bars the bike came with, the cable was not long enough to reach. I've never made a cable custom before. And it has that weird adjuster in the middle. I'd like to just have one solid cable instead.

And the chain tensioner idea is a great little piece of advice thank you! The other day it got so lose I had to put back on 4 times in a 8 mile trip! And retightening is already getting old after already doing it three times now in two months only about 20 hrs.

Changed oil three times already but last time it was still pretty clear but manual sais every 10 hrs.

O and got the fenders put on today! Very happy about that but I do need one more brace. It will work till I get it though.

 

[KCvale]

The fenders look great.
Nice job.

 

[KCvale]

Yee Ha!

The new re-designed Grubee 4G 4-stroke transfer case is in production and expected to be in the US in early 2015.

Besides an easier to manage mount plate, it sports the new KCK (KC's Kruisers) keyed output shaft with a dual set-screw 9T output sprocket.

This allows you to position the output sprocket directly and not by moving the whole engine.

From Don Grube a couple of days ago...

"We have the 9T & 10T KCK versions available now. What we don't have yet is a 16T belt drive pulley. We can make the output shaft any length you want including a set of U joints if needed to make your multi - shift design.

We will start stocking all 4G in our OK warehouse as soon as we can clear EPA for 2 cycle. We've had several sets backs doing that. Expect end of Feb delivery. "

From Don this morning...

"2mm tk. spacers are also included with a M5 screw installed on the end of shaft so once you decide where you want the sprocket it won't move.
10G can be ordered with 80T, 90T or 100T FW pulley;

I have some 80T and 100T, 10G kits coming.
10G will have M8 studs on the slide bracket and milled slots underneath to slide over engine mounting bolt heads to make shorter bracket span to fit our gt2A-s Alum. Frame better.
I will be stocking about 100 frames and 500 Skyhawk Gt5A engines as well.
Put the word out."

I'll be one of the first to be getting one and I can't wait!

 

[Pablo]

Nice!!! Not sure if Jim is following this thread. I'll bug him.

 

[KCvale]

Nice!!! Not sure if Jim is following this thread. I'll bug him.

This might be a better one.
http://kcsbikes.com/topic.asp?TOPIC_ID=800

I'll be sharing here of course but that is my main topic and Don is going to join in for more details as we sort the options that of course has a SBP involvement part ;-}

 

[Dan]

Congrats KC!

 

[WAYAFRO]

I just busted my Skyhawk gear box.
Joyriding after installed new pipe, tach/hour meter, and stuff.
I was going up this snowy hill 40% grade. Fifth time up I heard a little bang!
Guess I was too hard on it.
I was already looking at new ones. because...
I want to put starter/generator on 4stroke 49cc HS.
Is there enough adjustment in the output shaft of your new 10g to get away with this?
What is the gear ratio of the 10g compared to the one I got?
I was also looking at the simple double chain boxes.
What is there ratio?

 

[KCvale]

I just busted my Skyhawk gear box.
Guess I was too hard on it.

Looks like the clutch bell/first gear combo broke by the break area.

I want to put starter/generator on 4stroke 49cc HS.
Is there enough adjustment in the output shaft of your new 10g to get away with this?

No. You can't start a cent clutch engine from the output side, you replace the engine pull start with an electric option.
No, never done it but that's where you would put it.

 

[WAYAFRO]

No. You can't start a cent clutch engine from the output side, you replace the engine pull start with an electric option.
No, never done it but that's where you would put it.

Is it possible?

Looks like the clutch bell/first gear combo broke by the break area.

unfortunately these gearboxes are on backorder along with all there parts. But hay same place has motors with these for 279 and mounting kits with these fro 2somthin.

IDK I just ordered one of these to keep me rollin.
http://www.ebay.com/itm/400721444538?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
hopefully everything will line up. I'm in for one of yours as soon as you get some.

 

[The_Aleman]

<removed out of protest to certain "staff" practices in this forum.>

 

[WAYAFRO]

haha good thing I didn't get that one.

I hope the one I did get will work.

Prob has a 4:1 ratio right?