4 Stroke gearing. What speeds will I get from what gears ?

[Jcs1989]

Any one have any idea on gearing an speeds. Im running 49cc huasheng Xhd trans and 44 tooth sprocket 26" wheels. Tops completely out at around 36.5. cruises at around 26-29 mph. I'm trying to figure out what other cruise to top speeds are out there at what gear ratios...

 

[Longhaulin]

Have you done any mods to your motor? I'm currently running a stock HS 49cc with 7G Ghostracer trans and a 40 tooth sprocket and top speed is currently 29 mph. Motor only has about 200 miles... Kinda slow take off but lots of torque still even going up hills. Bike, motor and steel rear rack make the bike weigh about 80lbs and I'm 150 lbs, loaded with groceries she still accelerates up hill.

 

[Jcs1989]

Well I took the cover off the air filter an replaced it with a peice of custom shaped aluminum mesh. Made a difference going up hills. More torque accellerating from a stop. I still have to pedal to 10-15 mph an it pulls hard from there. Im sure when my Xhd trans goes ill probably go with the 7g. They say the Xhd doesn't last long. But I've got 100miles on it already. And I've completely regreased all moving parts and changed the break in oil early. Motor runs like a top. An has a good top end. I recently purchased a 27.5 cruiser can't wait to get it in and see how much difference there is between the wheel sizes. I stead of changing the gears. I think if I go with too much a higher gear it'll never climb even a slight incline lol...

 

[Longhaulin]

I've heard mixed things about the 7G. The clutch area was making grinding noise and getting really hot on a 23 mile one way trip to/from job site. I put a little grease on the transmission mount, tried my best to straighten the clutch pads but they're held in by two rods and the allen bolt.. oiled the bushing again, now she is smooth; the only thing that makes noise is the chain.

The stock carburator is acting up and ordered a manifold for NT carb... If I have time tonight I may take it apart and clean it. I sprayed carb cleaner in it already, took off and half a mile later she stalled out and wouldn't start back up. It stalled out when I left work the other day too but maybe half an hour later of fiddling with the choke and putting around she finally got going. And then started acting up again within a mile from home but I made it.

I was thinking of going with a 10G as I've heard KCvale mention but would have to order the tapered shaft motor as well... or maybe one of the 4G as Ive heard they're 3 different setups... but funds are lacking so I'm gonna see how long this 7G holds out. Bought 2 NGK iridium spark plugs but waiting to put those in after switching to Amsoil from Valvoline conventional...

Currently I cannot pedal this bike, only backwards a bit to use the coaster brake... So I push off with my foot and it goes 7mph and then I give her throttle and she goes, slow takeoff but torquee once she gets going. I'm also running 26 inch wheels on an old 1960 something Schwinn beach cruiser. My other ride is a 66cc 2stroke with 4200 miles, been riding that to job till I get the Schwinn and HS49cc going again... all 26" wheels. 2 stroke doesn't have as much power as the 4 stroke... it's had a leaking head gasket all 4200 miles and I've switched gaskets and tried some tricks which only work a short time then same issue re-emerges... But she gets me where I need to go. I'm sure the cylinder is warped but motor is a tight fit in the frame and I don't feel like taking it out... A Grubee Skyhawk motor it is.

 

[Jcs1989]

I haven't had any issues so far with the kit I received. It's the gas bike racer from gas bike.net. So far so good. The only issues I've had were a spring breaking an not noticing it til the chain finally lost the link lol. Waiting on links to come in before I can ride again. Keep me posted on the nt carb. I've heard good things about them. More power an reliability out of them supposedly. May want to check your fuel lines for blockage or filter. Or a faulty petcock. The deal that allows you to turn fuel on an off. I jus order a Schwinn swindler with the 27.5 wheels. From Wal-Mart. 99$ on sale. I'm gona cut out half the center bar to accommodate the 4 stroke engine. And then two 6061 aluminum plates on each side of the frame for strength an style. Should be a cool swap. Considering the 90s huffy cranbrook I have motorized now. The wheels aren't true an its extremely heavy. Must be 75+ lbs with kit installed on it. But im 145 so really im not too worried about the solid steel huffy frame breaking. I'm gona keep it as a spare for sure..

 

[Longhaulin]

To be honest I don't trust them walmart bikes. I had a Huffy Panama Jack and after less than 500 miles the bars leading to the rear dropouts cracked and broke on each side. 66cc Grubee skyhawk motor it had also, but that breakage could have been because I had a heavy duty chain and locks wrapped around the end of the build in rear rack... My other bikes have held up after thousands of motorized miles; one a Micargi Rover which currently has no motor but has had several and bike itself has gone over 10,000 miles-mostly motorized miles; The other Micargi Falcon which has a 2 stroke which just fits in the frame. The Rover might be able to fit a HS49cc but I'm not positive.

I may have made a mistake of rubber mounting the HS with rubber from bicycle inner tube in the frame, as the motor vibrates like heck but once it gets going cruising the vibes go away. I come to stop and the mirrors are vibrating and you can feel it throughout the bike. I have mounted the 2 strokes with rubber from bike innertubes the same way with no serious issues; Motor on Falcon is this way and still going after 4200 miles. With the HS49 build I replaced the mounting bolts with stronger ones of the same size from Ace hardware.

Another thing with the 7G kit that happened to me was the threads going into the motor to hold the transmission, well the top two both stripped but I put it together anyway and used blue threadlocker. I took it apart the other day while trying to figure out the grinding noise and heating issue and one of the top bolts was missing. Well I went to HFT to pick up a Metric and SAE tap and die set for $40, and I had my doubts and concerns but that did the trick I went up in size to a 1/4 x 20 or 28 and the new allen-head bolts stay in tight. While I was putting it back together the bottom two holes stripped out so I ended up tapping/threading all of them the same size.

Another thing; I upgrade the motor chain on all my bikes to 415 chain which is sold at Tractor Supply Company or similiar stores, Farm and Fleet if there is one of those out where you are? Easy to get half links for that size chain also and more durable than the kit chain, though a bit wider. I've been using the kit motor chain on the pedal side.

 

[Jcs1989]

Hmm my kit came with the 415 chain. I wondered if I could get the links at tractor supply. Lol shouldve gone that route instead of ordering them. So I could ride sooner. Lol oh well it's been raining here in Alabama alot lately. So no big deal. I'm in love with macargi falcon. The frame is just gorgeous. If they weren't 300$ I would have probably already got the GT. Im hoping the Schwinn will hold up to hundreds of miles tho. The huffy was mainly a test frame. Considering its solid steel its held up pretty good for the most part. Only thing I like about the Xhd trans I have is it's chain driven fully. Which I read gives a better top end. But like you ive suffered a bolt breakage in the motor. Luckily it's only one bolt so far. . I may have to try the little trick you mentioned if any further damage occurs.

 

[Longhaulin]

My mistake, the 415 is what comes in the kits. the slightly wider chain that Tractor supply might have is 41 and you can pick up offset (half) links. I had to tighten the pedal side chain, it's running 415 chain and used a 41 half link and master link to get it a perfect fit so no more slack. Had some small washers just the right size that I used to fill the gaps in the chain(width difference between two chains) It was too loose, it slipped off the other day when I went over a bump.

I rode around on the 7G last night and the bolt holding the bushing and clutch bell came out. if it wasn't for the cover there would have been a big mess and lost pieces in the street... It was just all real loose. I didn't put blue threadlock on it the first time and it stayed in. Put some on this morning, and had also put some on the bolts holding the transmission part but they all loosened up just very slightly...

You were right in your suggestion. It wasn't the carb... the other day my fuel line came off the petcock cause of the heat and bike sits in the sun at my job... I put teflon tape around the petcock and that is what ended up blocking the fuel flow. Gas was leaking out the line... I ended up puting a small hose clamp over the line instead. Which is what I should have done the first time...

 

[Jcs1989]

May try a springed tensioner. As long as you have a heavy duty spring your good. Takes an gives slack as needed. I've pictures the one I've made for mine. Works great. An yea I jus used some heavy duty zip ties for the lines on the fuel. Seen it leak a bit before so I added the zip ties. .

 

[Jcs1989]

This is the tensioner I've created it's pretty useful. An keeps the slack tight whenever. Even allows for easier pedalling.

 

[Longhaulin]

Cool spring tensioner, I may need to rig something like that. Probably it helps with changing to different size sprocket too i imagine. Though links probably still need to be taken out but tensioner wouldn't need re-adjustment.

 

[Jcs1989]

Right I jus took about a 3 to 4 inch long metal bar from an old harmonic balancer puller lol an added it to the tensioner with washers an a lock nut and a spring. Like I said I was really impressed. Only issued I had was the first spring I used(in the pic) was too small an broke after about 40 miles or so. That's why my chain broke loose. The spring broke while I was riding an after about 10 miles the chain popped off an the master link blew apart. Lol so becareful an make sure you get a good strong spring. An old trampoline spring would probably never break. Lol . .

 

[Jcs1989]

Oh an make sure you position it just right. I've also read pretty nasty things about the tensioner getting caught up in the spokes of the rear wheel. .