R&R Clutch on MX-5 / any info on MX-5

Discussion in 'Frame Mounted Engines' started by crackers, Feb 6, 2009.

  1. crackers

    crackers Member

    I'm trying to work the bugs out of the MX-5 I bought. It's been stored for about 14yrs. It came with no manual or advice from the seller, only the schwinn beach crusier it is installed on. I was able to take a test ride after it was compression started by the previous owner. It died on me when ever I came to a stop. He told me I had to raise the engine from the tire by a lever attatched to the handle bars. (Friction drive) This kept it from dieing but was a real pain and made it hard to control the bike while trying to stop. It did run good and the bike was worth the money by itself so I bought it. After geting it home and spending some more time with it I discovered that by setting the idle up that it would keep runing without raising the engine from the tire, it would just come to a stop and idle. I did need to peddle a little, just enough to get it rolling and then give it gas slowly to take off and after a few yards I could open it up an cruise between 25 and 30 mph. I've done some research on line and found out the MX-5 engine is no longer made and to my understandy parts are not available. I'm trying to restore this engine and drive train, it seams to be well made and worth the effort. That and it's a whole lot of fun tinkering with it. Plus as you all know there just as much fun to ride. I drained the gas tank and carb after geting it home the first day and put fresh gas and oil in it (25 to 1 mix). After reading lots and lots of threads I came accross one by srdavo (4818) The not-so magic carb. It looks just like my carb. so naturally I had to take mine apart, clean and adjust it. This was fun and It runs better and starts really easy now. My thanks to srdavo, great pics. Some times when I give it a lot of gas fast it feels like and sounds like something is sliping ( clutch or belt ) and there's a smell like burning rubber. I"m thinking this could just be the roller spinning to fast on the tire. MY curiosty got the best of me today. I've been dieing to know whats in the gear box, gears and a chain or just gears or maybe pulleys and a belt. What ever the case one or the other its going to need service. Up till now I've been affraid to pull the cover off thinking its going to explode like old watches I used to take apart as a kid. Anyway my confidence was high to day after reading all your guys & gals therads for several days now I just jumped in and pulled the cover off, to my suprise no oil or springs came popping out. Really nice and simple clean and dry two pulleys the one on the clutch drum in front of the other on a shaft going through the other side of the case where there's a bearing for suport of the shaft that the roller is attached to. There's also a bearig in the front side of the case that the other end of the shaft is pressed into. The belt looks new and doesn't seam to need adjusted at all It has about 1/2'' play up and down in its upright position and becomes tight when lowered on to the tire. I would realy like to replace the clutch at this point. I'm hoping seeing how the carbs are the same maybe the clutch will be also. I'm not sure how to proceed from here, I"m lost as what to do next,I"m just staring at it. I could just put it back together and ride it. It's not broke but I just want it to be the best it can be. Any idea's or info would be greatly appreciated. I will ad pic's when I figure out how to post. Thanks Dave

  2. uncle_punk13

    uncle_punk13 Guest

    It would seem as though it is operating properly, and honestly, until something goes wrong I'd judt leave it as it is. Minor maintenance and adjustments as necesary, but otherwise let it be and ride the heck out of it!If you are sure you want to tinker and fiddle with it, then please, posting some pictures would be a great help. I know this engine, but have no experience with it. So it would be interesting to us as well. Perhaps you would consider joining and posting this in the heritage section, so we all could participate, learn, and celebrate those enbgine kits that came before...
  3. crackers

    crackers Member

    Trying to post pics

    Hope these pics will help. I saw a snap ring on the front pully that will have to come off and I'm sure some type of puller will be nessary, but I'm getting way ahead of my self, I can't even figure how to remove the belt yet. It's snowing here in the moutains where I live so I won't being going any where soon on it, so I figure I can use this down time to explore the mystery of what makes it go. Let me know what you think. Thanks Dave

    Attached Files:

    Last edited: Feb 8, 2009
  4. az cra-z

    az cra-z Guest

    I copied some pages from my MX-5 manual, PM me your address (check your PMs!).

    A general FYI: The "gear box" on the MX-5 has TWO centrifugal clutches - the front one works normally when you are moving, the rear one is a "reverse" clutch that engages only when you drop the roller onto the tire to start, then disengages when the motor kicks in. I used one of these for a couple of years, and not too long into the first year the drive roller inside bearing burnt up and I had to have a scooter shop replace it as I just couldn't figure out how to get to it! (the owner's manual is really worthless)
  5. crackers

    crackers Member

    Thanks az you are the man! I never thought I would be looking at a complete schematic of the engine and drivetrain. I can't thank you enough. I'm taking the page's you copied for me down to kinkos to have them enlarged and laminated. Its great knowing the correct factroy recommended spark plug and the gap. Neither of which I was running was correct. The Preventive Maintenance check list is cool also, it's all good. I'm going to be alot more confident dismantling the clutch's having a blueprint to reassemble them with. I will take pic's of the operation for a later post. Thanks again