engine rev's but doesn't spin tire.

GoldenMotor.com

cottonball

New Member
Feb 26, 2009
22
0
0
Colorado Springs
Hello,

I recently built a 4 stroke with a hoot transfer case and realized that it was a piece of junk after I ordered it. I have 33 miles on it and today when I was pulling out of the drive way the back tire stopped receiving power from the engine. Any idea on what pieces I could check out? Keep in mind I'm not mechanically incline and would appreciate the best descriptions possible when referring to particular parts.

Thanks for stopping by.
 
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cottonball

New Member
Feb 26, 2009
22
0
0
Colorado Springs
After looking at it a little, I realized if I pickup the rear of the bike, and give it some gas it will turn the back tire but with a lot less power then before. If your on riding the bike there's no way it can generate enough power for you to notice it's even working. Any idea what would cause this all of a sudden?

Also does anyone have a link to a guide on how to tear down a HOOT gear box? I'm having trouble even getting the "8" cover off the box.
 

Fishermanblues

New Member
Aug 24, 2008
38
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Tucson Az
I don't know much about 4 stroke kits or HOOT gear boxes but what you're describing sounds to me like a clutch problem. I don't know how the clutches work on these kits, but that is where I would start. Just my two cents while you wait for somebody with more experience with 4 stroke kits to reply.

Good Luck,
Andrew
 
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Norman

LORD VADER Moderator
Jan 16, 2008
2,605
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pampa texas
what your describing sounds to me like a centrifugal clutch problem you might have oil or grease on the clutch shoes and will need to clean them off using a good degreaser like brake clean or a carb cleaner. could be a broke spring or a twisted off shaft/ nut on the clutch.or stripped teeth on a gear.
Best guess is oil/grease on the clutch.
I'm about 8 hours drive from you and if you want come see me I'm retired I do not charge an arm and a leg for help.
 

cottonball

New Member
Feb 26, 2009
22
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0
Colorado Springs
@Norman

Thanks for the info and your offer. I would like to try and fix it myself first, but I may take you up on that offer if all fails. Do you know where I can get a guide or diagram on how to take apart this gear box? I took all 6 bolts off the side and now I can slide the gear box cover up and down a little but cannot take it off. I looked all around and don't see any bolts holding it together.
 
Jun 25, 2008
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sadly i think the previous diagnoses are not the case for you, i've had the exact same problem and its due to the woodruff key/spline/keyway what ever you wanna call it, in the gearbox being made of chewing gum. I think you'll find the gears are spinning around their shafts....can be mended
All you need to do to confirm if i'm right is open the gearbox cover and either observe them in action or a safer bet is to manually turn them, remove and inspect.

I suspect you'll find tiny flakes of shattered metal (or what more accurately resembles solder its that poor!)
 

cottonball

New Member
Feb 26, 2009
22
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0
Colorado Springs
@Milegajo

Could you tell me how to take the cover off? As stated above I took out the 6 or so bolts holding the side cover on and there's still something on the inside holding the cover on. I looked all around and don't see any other bolts or screws to undo to take off the cover. Any help would be greatly appreciated, and thanks again for your thoughts on my problem.
 
Jun 25, 2008
455
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are you able to post a pic? even if you grab a library pic off google images of the gearbox
If it looks like a figure of 8 then its a HOOT if its more rectangular its a Grubee.
 

cottonball

New Member
Feb 26, 2009
22
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0
Colorado Springs
Ok, so I went home for lunch today and was able to pop off the cover. Everything looks normal to me, but as stated earlier I'm not the best at mechanics. There was a TON of greese in there. I did clean it all out pretty good. Will clean more when I get home. But, I didn't see any broken parts or anything.

Can anyone tell me what this little piece of metal on the left goes to?



Here's how clean I got it on lunch, the grease was pretty wet and sloppy.
 
Jun 25, 2008
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Check the shaft, i think you'll find the other half embedded in the keyway slot of the shaft. If im right that peice in the photo will fit in the gear slot snugly, but its supposed to protude out to slot in the shaft and grip thereby turning the gear.
 
Jun 25, 2008
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That said it will probably have fallen out. If what i'm saying rings true and you find this is indeed the problem, get in touch with pablo as i think he should have the peice of metal you need.
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
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the small piece of metal looks kind of like a key for the shaft but sheared off I'd like to see more on how all parts fit together and where did that small part come out from? the gear in the picture has a slot that looks like its supposed to be keyed to a shaft.
If you can take off the clutch its on the left the big round thing with the small gear and socket head cap screw holding it on under that is the clutch shoes and they may be greased up. That small metal part has me thinking you've got a sheared key on one of the rotating shafts and that will stop you dead in your tracks. you doing good trouble shooting it keep up the good pictures we are all here to help.
something else one of my scooters that I want to sell has its clutch in an oil bath and is designed to run in oil so the clutch might not need to be cleaned I'm betting its your mystery metal bit aka sheared key. That is a 4-stroke set up looks kind of cool I'd like to get my hands on one of those 4-strokes and see what I could do to it. big evil grin!
something else that metal part could be a sheared off tooth on one of the gears.
Norman
 
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cottonball

New Member
Feb 26, 2009
22
0
0
Colorado Springs
I'm still at work, but if the key was sheared would it still turn the small gear coming off the motor when I give it the gas? Because that thing spins just fine when giving it gas. Although there is no pressure on it right now so that could be why. . .

Also, I too thought it could be a chipped tooth on one of the sprockets, but after comparing the size of the gear teeth to that metal bit I doubt it. The metal bit is a good 25-40% thicker then the gear teeth.
 
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Norman

LORD VADER Moderator
Jan 16, 2008
2,605
6
38
71
pampa texas
get some pictures posted of parts in place and where they all go that will help. and a picture of the parts that are missing in the picture of your side view showing the clutch.
 

cottonball

New Member
Feb 26, 2009
22
0
0
Colorado Springs
Ok, I fixed it. That piece of metal was the thing that holds the small gear in place behind the big one on the right. I put it back in and now it actually spins the tire. I took it around my neighborhood up to mid 20's and everything went smooth. I did notice the small gear that is behind the bigger one is missing 2 teeth. Looks like I will have to ship that piece back to gasbike .net and have them replace it for me.

I just want to thank everyone for their input and assistance. My mechanical confidence is up and I'm less frustrated now that I know I can fix it with a little help from this wonderful forum.
 
Jun 25, 2008
455
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Ok, I fixed it. That piece of metal was the thing that holds the small gear in place behind the big one on the right. I put it back in and now it actually spins the tire. I took it around my neighborhood up to mid 20's and everything went smooth. I did notice the small gear that is behind the bigger one is missing 2 teeth. Looks like I will have to ship that piece back to gasbike .net and have them replace it for me.

I just want to thank everyone for their input and assistance. My mechanical confidence is up and I'm less frustrated now that I know I can fix it with a little help from this wonderful forum.
We had faith in ya, i know exactly what your feeling right now! We all do, its a steep learning curve to begin with but with help from these fine fellows it gets easier until you can pass on the favour.

All the best but keep a watchful eye on those geasr and keys, mine failed three times before i decided i'd had enough and rebuilt the gearbox
 

cottonball

New Member
Feb 26, 2009
22
0
0
Colorado Springs
I'm actually going to replace the gear with the chipped tooth and get it in good working order then sell it. I'm about to go to the desert for a little bit and don't want that engine just sitting around for half a year. So I figured someone that could put it to use would do the bike better then me. But as soon as I get back I'm going to build another probably a 2 stroke haha. I'm already excited about it. Thanks again for all help. I will continue to browse the forum and soak up knowledge and hopefully one day contribute to it.