My Murray Monterey Build

junglepig

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Oct 30, 2018
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#21
So, I'm cruising (not far from home) today after putting on a better clutch lever (The kit lever broke) and suddenly there's a very wrong noise from my HT motor. I check everything drivetrainwise that could hurt me, and then head home. I pulled my plug and it looked like maybe the piston had just kissed the end of the plug electrode, so I pulled it off and took down the top end. I'd been meaning to do this anyway to see what kind of rod and piston were in this engine anyway. I found nothing wrong. While I had the jug off, I got my Dremel out and cleaned up the transfer ports which were ugly, ugly, ugly from the factory, and put it all back together. I had noted a crack earlier in my clutch cover. I'm pretty sure this was the source of the noise. A chunk of aluminum had broken off the edge and fallen down into the gears. And there were crushed aluminum shavings all in there. I blew it out with lot of air and regreased the gears. No troubles now. The minor work I did on the transfer ports had no discernible effect on how the engine runs.
 


junglepig

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Oct 30, 2018
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#22
Ha! If you have an old lawnmower they usually have good quality boots. Maybe a junkyard
I've got some boots and terminals and wire and plugs ordered. Of course, I got to reading last night about the whole resister vs non-resister debate, and whether not having any resister components (wire, cap, or plug) would be harmful to the CDI. I've decided to run it with a 5K resistor boot. I think that's what's on it now, and what most CDI ignitions spec. Then I can run it with non-resistor plugs. I've ordered several styles and heat ranges to experiment with while I'm playing. My wire will be copper core with a dressy fabric exterior.

In better build news today, my front brake came, so I drilled out a mounting hole for it and got it installed. I feel much better now. I had been reaching for a brake lever with my right hand all the time, and it just wasn't there on this old cruiser. She stops so much more reliably now!

Next steps will be lighting. I got a little headlight that runs on 3 AAAs, or 4.5V right now. If it's bright enough as is, I'll set it up to run on either 5V (USB) or 12V. I also have a 12V tail/brake light to install. But before all that, I'm going to attempt to put my own lighting winding on my stator. The new style stators don't have a lighting coil on them. Some have a white wire, but it is just soldered to the same lug as the blue wire, not to a second coil.

I think there is room on my stator to wind a coil of 26ga magnet wire that will provide at least 7.5V and 500mA nominal. 3 W should be plenty for my LED lighting, and will not be a significant burden to the engine. Specs I have found here and elsewhere for the original coil design is 300 turns of 26 ga, and a resistance of about 2.3 ohms. At 41 ohms/1000ft for 26 ga wire, this works out to 56ft of wire and an average diameter of 0.71", all of which passes the feasibility sniff test. (Normally the lighting coil is underneath the CDI coil. I don't think either will suffer too much if I wind the lighting coil on the outside instead. I plan to rectify the output of that and use it to charge an inexpensive li-ion USB pack. I'm thinking a 3 or 4 cell pack of 18650s. I'll use that (with a boost module) to power a 12V system for lights & horn or other electronics. I figure having a fully charged USB powerbank on the bike is a bonus in the event of a dead phone battery.

I'll share details of what I do and how well it works. I hope this little project will be helpful to others. All the components are readily available and require no special tools or skill beyond soldering. Probably won't get into it much 'till after Turkey & Shopping weekend.
 
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junglepig

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#23
I wound 300 turns of my 26 ga magnet wire over a stator from ebay. I scraped the ends and soldered one end to the black ground tab. The other end I soldered to my white wire, and covered with heat shrink tube.

300 turns on the outside of my coil is a lot of wire - about 3.4 ohms, or about 83 ft. And, it may be just a little too much to allow me to install it. I hope to try it tomorrow.

If it won't sit flat, I'll have to remove a few turns and try again, but it's close.

Things are busy this time of year, so I just thought I'd make a note here of what I did in case I don't get back to it for a while.
 
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