Clone to Honda conversion
- Thread starter Deoodles
- Start date
Roy Chambers
Member
I like that one! It look's Lighter and the Top Ring is moved down away from the Heat of the combustion chamber !
RC.
Golden! The piston that Kirrbby recommended did the trick. Nice deck height. Runs a little quieter; took it out for a few miles and no knocking. Thanks Kirrbby 
. I changed the oil. Some star dust, seems average. in the 40’s here so never got over 50 Celsius. I’m going to put everything back together and wait for some riding weather to fine tune it.
. I changed the oil. Some star dust, seems average. in the 40’s here so never got over 50 Celsius. I’m going to put everything back together and wait for some riding weather to fine tune it.The weather is in the 60’s today so I thought I would attempt to rejet the carb from the 108 to the 124. I spoke with Pat last night about the best place to start. I knew it was running lean. Symptoms were excessive bluing of the header, a dead spot off idle and decel popping. I started with a 17.5/135 in the VM20. I changed them to 22.5/150 and the bike woke up. The dead spot is gone and no decel popping. Idle is nice and smooth. The pipe is blue so I won’t be able to use that as an indicator. I need some saddle time to know if further tuning will be needed but I’m at a good starting point. I’m keeping the 17/33 sprockets to start but have a 31 that fits if needed.
With this displacement, VM20s usually want #20 or #22.5 pilot and #140-150 main.
If you have an IR thermometer, you could take some temp readings at various locations on the top end & exhaust. Once you've established which, specific, locations you're going to check you'll have enough of a checklist to create a fairly detailed view of how the engine is operating. That can be very handy...and informative.
If you have an IR thermometer, you could take some temp readings at various locations on the top end & exhaust. Once you've established which, specific, locations you're going to check you'll have enough of a checklist to create a fairly detailed view of how the engine is operating. That can be very handy...and informative.
I don’t know squat about heat and the information it provides. I have an IR thermometer. I went on the longest ride so far on this build. Probably 10 miles max. It was close to 70 deg. The ride lasted 20 minutes. Neighborhood and secondary roads. When I got back the dipstick thermometer read 195F I shot the head and it read 160, the cyl on the left read 260, the head pipe read 200. What does this tell me and are they about expected? BTW, I cant Believe the torque difference. It will pull the front wheel in 3rd. Quite a difference from the 108cc
You will learn...quickly, too, I reckon. Those are all good numbers. I suspect that you'll see much higher peak temps, especially with the oil and that spot where you got 260F, once you start leaning into this tight engine for some miles and in higher ambient air temps. (As long as oil temp remains below ~115C/240F and cylinder/head temp remains below ~300F you should be fine. Just remember that some parts of the head, like near the exhaust port will get a lot hotter.) First thing they'll tell you is when to let the engine cool down. Next will be the break-in status. As the miles roll on, frictional heating will decrease. After the engine is broken-in, you probably won't have to check any temps other than oil...unless you suspect something. I usually shoot temps on my main rider a couple of times per year... preventive curiosity. It also lets me see how the oil cooler is working; there's never been more than~2-3C variation between the hottest & coolest points. For example, a sudden 20C+ temp spread would indicate uneven oil flow.
My points here are monitoring break-in to prevent hotspotting and getting everything dialed-in before you take it out for a 100+ mile road workout. These motors can survive being pushed really hard...if everything is functioning optimally. Once you get things dialed-in, they'll probably stay dialed-in...it's all about getting there unscathed.
That wheelie-happy attitude in 3rd gear makes me think that you're likely still under-geared.
I think I’ve finished up with my winter projects. Kirrbby had the header shield I was looking for and Red69 shared a source for the electrical boot I needed. Thanks guys! The exhaust is a D style from webikes and so far it’s fine. The tach is Chinese cheap. I modified the wire harness to create a plug in the harness for the tach and changed the tail light from A/C to DC and the bulb is now a LED. I’m ready for riding weather now.
Your clone must have slightly different electrical circuitry. The Hondas used DC to power the TL & BL. What's the worst that could happen with cheapie gauges? As long as they work reasonably well, what's not to like? FYI, I used to use a Jincheng speedo (K0 knockoff) for testing work; it was about as accurate as the OE Nippon Seiki. From what I've heard, they do wear out...unlike the OEM versions. Never ran one long enough for that to happen. If it did, there's not much money or time involved. There are plenty of electronic options available these days, so no worries about being "stuck". In your place, I'd probably have done this project just as you have...FWIW.
The only possible issue I have with Chinese wire harnesses would be the splices. Those are easily unwrapped & soldered. Aside from that minor issue, a good source of cheap, brand-new, wiring & connectors. I like your idea of modifying the harness to suit your applications...another upside of custom projects.
The only possible issue I have with Chinese wire harnesses would be the splices. Those are easily unwrapped & soldered. Aside from that minor issue, a good source of cheap, brand-new, wiring & connectors. I like your idea of modifying the harness to suit your applications...another upside of custom projects.
I spent today in the garage getting ready for riding season. Did the nut and bolt inspection and lube. Also wash and wax. Last was an oil change. The 3rd one since the build. It went well. Really no stardust and the screen is clean. I’m going to put about 3 hundred miles on this oil then check the spinner. I also had a chance to take it out and see if the tach was close. In 4th I had it at 5k rpms and the speedometer said 36 mph. I’m thinking a few more weeks and I’ll shake it out.
Ok Kirrbby, I put ins. And the tag back on. Legal now. I rode where I always ride. The first big hill with the 108 was always 45 in 4th then near the top down to 40 so into 3rd and crest the hill in 3rd at 50. Tonight was much better. 45 approaching the hill in 4th and 55 at the crest still in 4th. On places where I could hit 50 I was hitting 60 and the tach said 9k. I know it’s still a tight motor so I stopped after 7 miles and it was close to 100c. After it cooled down I ran it about 10 miles and was hitting 60 for 3 or 4 miles. I stopped again and was at 115c. Cooled it down and went another 9 miles at an easy 45 / 50 and it was 100c when I got home. I used the infra red temp gun and shot some temps. The cyl was close to 300 deg, the crankcase was 220 and the head was 240 deg. Overall quite an improvement over the 108 but as racerx said once a 125 is the price of admission for a road bike. I believe that now and wish I had listened then.
kirrbby
Well-Known Member
That's awesome Deoodles.
Good that you're sticking to a easy break-in too. I've recently become a believer in the easy break-in :--)
I hope this engine is the one that makes your bike complete...finished...reached the happy place. It's a great feeling when you can actually hold your own, out on the street...power to spare. Maybe you'll have a whole new appreciation for riding your CT70 this season.
Good that you're sticking to a easy break-in too. I've recently become a believer in the easy break-in :--)
I hope this engine is the one that makes your bike complete...finished...reached the happy place. It's a great feeling when you can actually hold your own, out on the street...power to spare. Maybe you'll have a whole new appreciation for riding your CT70 this season.
cjpayne
Well-Known Member
There was a couple of times I didn't, but otherwise thats what I did to my HK1. It runs great. After around 800miles or so, check the points, Tchain, and A/F. Mine liked a little massaging. Every little bit counts and tuned it by ear. Cruises 40-45....no problem
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