How to convert 2 stroke automatic to manual?

Discussion in 'Motorized Bicycle General Discussion' started by silverbear, Apr 19, 2010.

  1. silverbear

    silverbear The Boy Who Never Grew Up

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    As chronicled in the centrifugal clutch blues thread I've had my fair share of misery over the past couple of weeks with a slipping automatic clutch. Every time I think I have it fixed and proclaim success, a few miles from home I discover it slipping again and then push the bike back up the mountain. While great exercise this was not the plan. On this thread I will not go into what has been done, etc. On to the second automatic. I was so happy with mine last summer that I decided a month ago before the riding season began to buy a second pull start automatic. When the first crapped out on me a couple weeks ago I got busy setting up the new one. I'll skip all of the other issues with that kit and get to the twenty feet of successful riding before something went in the automatic clutch so that it no longer engages with the engine. No it is not slipping like the first one, it is not engaging at all. I had at first thought to ask here for suggestions on fixing it and think instead I will look into whether or not there is a way to convert an automatic into a manual clutch engine. I have had it with automatics. I love them when they work, but both bikes are sitting there with engines that run great and won't either one propel the bikes forward. I'm not a quick learner, but not a total fool either. Of course I am hoping the seller will do the right thing and replace the new engine as he should, but am also realistic enough to know he will likely try to either ignore me or say I did something to wreck his wonderful motor. So far there is a deafening silence. No names here at this point. I'm not interested in giving anyone a hard time. I just want to ride my bikes. Back to the question. Is there a way to convert the engine by removing the automatic clutch assembly and doing something or other magical to make it operate manually? Otherwise I may be scrapping two motors which run quite well, one with a few hundred miles on it and the other twenty feet. Major Bummer. (General Electric, Sergeant Pepper, Corporal Punishment, Private Joke... I'm trying to cheer myself up, but it is not working.)
    SB
     
  2. corgi1

    corgi1 New Member

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    I think you could ,(if these are 2 stroke china girls ?),just add a gear in place of the centrivical clutch ,Have you had one apart ?(the cen clutch and the cover under it),is there a clutch lever on the left side that operates the regular clutch on the motor?
     
  3. corgi1

    corgi1 New Member

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    Along with the gear ,you may need a wodworth:confused: key
     
  4. Cabinfever1977

    Cabinfever1977 New Member

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    There is a cable that operates it as a manual as well as automatic.
    You would have to remove the centrifugal clutch part and i think u may have to add a small gear in there. Plus you need a regular cover.

    I was also wondering how to make it just a manual as i always pull my clutch in when stoped.
     
  5. AaronF

    AaronF New Member

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    If this seller is a Ebayer yes he will ignore you,not communicate and eventually block you from his great services.

    Like Corgi and Cabin mentioned,you would have to remove the centrifugal pack,put a small bevel gear on the shaft and a new cover to convert over to manual.
     
  6. silverbear

    silverbear The Boy Who Never Grew Up

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    I knew when I bought this that customer service would be on the thin side and made a gamble based on OK experiences in the past. If a seller is going to be willing to replace an engine, then it is going to cost more in the first place or he won't be in business long. I don't imagine there is a great profit margin on this kit, so replacing it would hurt. On the other hand he sells a lot of kits. I'd rather leave name calling alone in this thread. I took my chances and am paying the price. That's what happens when you try to go as cheap as possible. Can't have everything. If I want a replacement or money back guarantee and great customer service then as a buyer I have to be willing to pay for that. It is a choice we all have to weigh when making an engine purchase. I think on the next engine it will be a pk-80 with a pull start (no automatic) from a seller who advertises here on the forum. I value this forum and have profited from what I've learned here... so buying from one of our sponsors is a good kind of give back. As a penny pinching old tightwad, coughing up the cash is like a cat giving up a hairball, but I can do it. I did get a response from the seller giving information for a possible fix which I can't make heads or tails of, but will continue attempting to decipher. At least he is trying, I think. I have more faith in the good people here for guidance and my own perseverance.
    This bevel gear... is this what is there in a manual clutch engine and would that one work? Why couldn't the old cover be used since it is just a cover and doesn't really do anything? I already have the short pedal crank in place to clear the automatic cover. if possible, simple is good.
    SB
     
  7. Cabinfever1977

    Cabinfever1977 New Member

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    If ur're old cover still fits after, you could use it. But im not sure it will since the bolt holes are lined up with the centrifugal clutch pack.
     
  8. silverbear

    silverbear The Boy Who Never Grew Up

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    Yeah, I see what you're saying. Nothing is ever simple, is it? You know, it kinda sounds like if I can't fix these centrifugal clutches, then just buy replacement motors (not automatics) and use all the kit parts from the old motors. By the time you find a bevel gear deal, buy a new clutch cover, successfully make it all work after tearing out hair, shamefully crying real tears and wasting countless hours... might as well get a new motor from a reputable dealer and start over. I guess I'll try to fix them and if that doesn't work then get new motors. Thanks,
    SB
     
  9. silverbear

    silverbear The Boy Who Never Grew Up

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    I am attempting to open things up for a look and have removed the smaller cover over the centrifugal clutch assembly. In the close up photo the centrifugal clutch itself is shown with the hole in the center where a bolt fixes the assembly to the crank shaft. I removed the bolt and attempted to wiggle the assembly loose from the crank. It won't budge. In staring at I finally realized that the outer part of the hole is threaded for a larger bolt to fit into just the assembly part and not all the way in to the crank, which it would be too big for anyway. I figured if I used a bolt of te right size and something like a fender washer or some sort of spacer that I could remove the assembly that way. Then I remembered how Norm had spoken of a clutch puller for the manual clutches and figured since either type would bolt to the cranks shaft that the same puller might work. So I looked up the puller on a sellers list of parts and discovered it would cost about ten bucks with shipping. Plus I have to wait for the puller. So, does anyone know what size bolt this is? It looks like it would be right hand thread. Anyone know?
    Once the assembly is removed there are five bolts holding the underlying clutch cover in place and when I'm able to remove that the parts I want to see will be revealed. In looking at the PK-80 engine kits I see that the clutch puller is included. Wish my seller had included one in my kit, but every dime counts I guess and smart me wanted to pay as little as possible...hmmm. I sure did save, don'tcha think? Anybody know that bolt size?
    SB
     

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  10. AaronF

    AaronF New Member

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    The cent pack will come off with hand force if you can get a good grip on the outer side.If I remember right the bolt was 14mm with a lock washer on mine.

    Like ya said you'd probably be better off buying a replacement motor or if you want the quality & performance,Pirates should have their top quality motors here soon :)
     
  11. silverbear

    silverbear The Boy Who Never Grew Up

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    The bolt I'm referring to is not the one that holds the centrifugal clutch to the crank, but the threading in the clutch adapter which is larger that is for the clutch puller. This one will not budge and there was no slipping or wearing down of the crank, so it is very snug. I have a strong grip, but no deal, so I need the puller or one I make up myself which is why I wanted to know the thread size. The pk-80 I'm talking about would be the stock motor which is still supposed to be a very good one even without modifications. I'll do my own porting and my own expansion exhaust. I can buy Jim's head later if I want more power yet. I'll get one this summer regardless even if I can make these automatics work.
    SB
     
  12. AaronF

    AaronF New Member

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    Ah gotcha :) Well if your plan for right now is to convert over to manual,you could take a flat screwdriver budge it behind the cent pack and push out up against the cover.However doing so would most likely crack your cover but you might get lucky and not break it if your 'careful' I'm pretty sure you'd need a new clutch cover anyways when you go manual.So this might just be worth saving a few $$ on the puller.I may just have a extra puller I could send ya for free if you absolutely have to go this route.
     
  13. silverbear

    silverbear The Boy Who Never Grew Up

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    I'm pretty sure that would break something, likely the cover. I want to be careful with what I'm doing since I may be able to fix the automatic, which would be great. And I don't actually know for a fact that I can convert the automatic to manual as I have yet hear from anyone who has done it and I'm no mechanical wizard. If it can be done that's great, but I don't know that yet and I don't know where this beveled gear would come from.
    Thanks for the offer on the puller. Someone may give me a bolt size and a few minute trip to the hardware would do it. What a hassle all this is for a new motor. The seller gave me vague directions for a fix that involves some plates hidden under the clutch. When I asked about how to remove the centrifugal clutch adapter I was asked to send a picture. So I did and will wait and see. How's your put together motor running?
    SB
     
  14. jviperm

    jviperm New Member

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    This is what you will need to convert to manual clutch

    Large Round Flat Head
    Small Bevel Gear
    Clutch Access Cover
    Woodruff Key

    All these parts are avable at Piston Bike.com
    you will also need a centrifugal clutch puller. I'm not sure wher to get one of those.
    I hope this helps
     
  15. jviperm

    jviperm New Member

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    Also don't pry on the centrifugal clutch all you do is pop out the clutch weights and the gear housing leaving the center bore of the cluch in place.
    I know from experience!
     
  16. corgi1

    corgi1 New Member

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    I would remove the centrivical clutch befor getting a gear and look ,,,it may "not" be a bevel gear on the clutch ring ,,,,and the centrivical clutch cover should work w/a standard set up ,its just a larger 2 piece cover to make room for the clutch bell and 3 shoes
     
  17. corgi1

    corgi1 New Member

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    One of these dealers on the sides of this typing page has to have the gears your looking for ,I've seen them on a clutch parts list,and the keys too
     
  18. corgi1

    corgi1 New Member

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    A thought ,If the centrivical clutch is slipping on the shaft,and if there was a length of rope fed into the spark plug hole (like when taking the bolt loose) could you twist it on the shaft by hand and slide it off?,and have you tryed removing the other one from the motor yet?

    Another thought,,If the centrivical clutch is acting tight on the crank shaft,could it be that the flower nut on the clutch pucks needs adjusting?(you would still need to remove the centrivical clutch to take off the lower cover to do this)
     
  19. silverbear

    silverbear The Boy Who Never Grew Up

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    Thanks for the latest posts which are very helpful. I found the parts mentioned at Piston and they came to $35.00 (woodruff key, large round flat head, small bevel gear, clutch cover & gasket and a gear puller which looks like it is also a clutch puller. Shipping brought the total to $43.20. I priced a new stock PK-80 from Pirate and it is $100.00 with another $25.00 for shipping for a total of $125.00.
    I think I will pursue fixing the automatic clutches for the time being. If unsuccessful then I may just put them on the shelf and wait for a donor motor which would have all the parts and are not the kind that would wear out. Maybe someone here on the forum has a dead standard engine they would let go for very cheap plus shipping. Or at some point I might have a worn out one I don't want to rebuild and can cannibalize that. I think I'd rather buy a new engine than pay $43.00 for parts. But I will need a clutch puller. Information is a very good thing. jviperm, it sounds like you have done this yourself or at least investigated doing it. So this conversion is possible? Did it work out for you? What was the original problem with the automatic... had it been slipping?
    SB
     
  20. jviperm

    jviperm New Member

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    I just thought of another possible problem you may have a slipping manual clutch. Because when I installed the centrifugal clutch the manual clutch loosened up so I Had to take it all apart to fix it
    Ok now how to get it apart.
    Carefully pry on the centrifugal clutch outer housing all the way around. It will loosen up and you will be able to pull the clutch weights and the outer
    housing off the motor. Then you can get at the screws for the clutch cover.
    With the cover off put the outer clutch housing back in and spin it by hand to see if the manual clutch spins. Make sure the manual clutch is engaged with the rear wheel locked in place if the clutch gear moves the manual clutch needs to be tightened up If the manual clutch is not slipping then you will know that the centrifugal clutch bad.

    .bld. Hopfully this will be you when you done reddd
     

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