1975 CB125 Tracker project

Ah, I keep forgetting your up north. I had a float do that on something, as I was soldering I kept finding more and more pin holes...then it finally got hit enough and popped the side off....much easier to get a fresh new one.
 
I’ve had good luck with them. I received a faulty float once from them and they sent me a new one no questions asked immediately, so good customer service if you ask me


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Maritime said:
Ordered 2 of these. coming x china I want a spare on the bike with him incase it...
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I’m going to follow your (and Trek97’s) lead on the 6v H4 headlight conversion. Are you happy with bulb? There seem to be several varieties on eBay. Do you have a link? I was recently burned by “6v” led signal lights from eBay. They worked but were really 12v lights, and too dim at 6v.

Did you wire it up just like the original?
 
SpaceTrucker said:
I’m going to follow your (and Trek97’s) lead on the 6v H4 headlight conversion. Are you happy with bulb? There seem to be several varieties on eBay. Do you have a link? I was recently burned by “6v” led signal lights from eBay. They worked but were really 12v lights, and too dim at 6v.

Did you wire it up just like the original?
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Here is the bulb. https://www.ebay.ca/itm/154027546386?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 I got 2 just in case but so far it's nice and bright. I ended up buying signals I like then buying 6V bulbs and converting them. they are also nice and bright. The conversion was easy and the bulb plugs right into the socket on the bike.
 
ordered this too. My big ole size 12 feet and a little tiny shifter do not work well with the fused ankle. Magoo has almost as big of feet so he'll likely find this better as well.
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OK so I got the float installed and it fixed the too much gas issue. Now I need to re-tune the carb.
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I tried this but can't seem to get the settings right. It was hard to get it started but once I did I rode it a bit to get it warmed up well. It wouldn't rev to redline and WOT 5th got me 70KPH / 40MPH that is way below the claimed top speed. I got it back to the garage and had a hell of a time to get it to idle etc and turning the air screw didn't seem to do anything. I'm going to try it again tonight but what else could be the cause. I didn't look at the jet sizes as the PO said he never changed anything and he was pretty sure the other person who he sold it then bought it back from didn't either. it wouldn't stay running unless I set the stop to make it idle at 1,500 RPM trying to settle it down to 1,200 it stalled, it would fire back up but only if I opened the throttle about half way, kick, vrooom! then hold the throttle open a little to keep it at 1500??? I wonder if the pilot got plugged or something?? It seems to want to run only on the secondary jet needing the slide up enough to get fuel from it?
 
this may help. I think I had the air screw out too far to start with. I thought I read 2 turns out +- 1/2 but here it says 1 1/2 +- 1/8. I was doing 1/4 turn adjustments and that's too much if the +- variance is 1/8 IDK what I read to get the other numbers in my head. I was also tired and sore from changing the Yaris Manifold etc. LOL.
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One last thing, I didn't pull the carb off and check float height if too low would it cause the hard start needing throttle to stay running issue? I know if too high it runs way crap and fuel comes out, so too low would maybe not supply the pilot circuit enough and you need the main jet to get enough fuel to idle and run? anyway I'll pull the carb and check the float height too.

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Any luck getting a smooth idle? Is your needle set in the middle (third notch from the top?


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I’ve made some progress but it still runs poorly in the 5-6000 RPM range. The plug is showing a rich burn (very black). I adjusted the needle ending up at the leanest setting and there seems to be improvement but not a solution. Air intake is a pod. I tried running with it removed and there was no difference. The float is at spec but next I’ll try lowering the fuel level just a little to see if that leans it out. It seems weird I’m having to go to great lengths to lean the fuel mixture. Before this, I was concerned adding a pod would cause the opposite problem.


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Are the jets new or what came in the carb? The top end richness could be any number of things but the main jet may have been "cleaned" in a way that left the bore oversize. I like to start with new jets where there's any doubt about their condition.

At the bottom end, the pilot jet and matching air passages are tiny and clog easily. Many carbs dishcarge the idle mixture though a tiny hole on the floor of the carb close to the front edge of teh slide. That is often blocked.
 
Thanks Teazer. I made sure carb cleaner came out of that passage but it very well could have gotten dirt in the mean time. I'm hoping after I cut a chain saw tank of wood that I can then get Magoo out to help and we'll follow the manual. If we cant get it after a few tries I'll pull the carb, re clean and chexk the jets etc.
 
Ok. So Mon was a holiday and after changing out 2 thermal pains that had shit the bed I found some time. Turned the air screw in, then back out the 1.5 turns. Choke on, 2 kicks and fired up. Let it run a min until it ran ok no choke. Then took it for a ride. Didn't like WOT at all but keeping it at half I managed a smooth 45-50 MPH for 30 miles roubd trip to the only open grocery store for some supper items. Got back and then adjusted the screws again. Inwas able to do the 1/8 turns and got it tonchange idle up and down and landed right around the 1 and 5/8 turns. Didn't get a chance to ride it again. Next what I need to do is check needle position for the 1/2 to WOT. Once that is sorted it should be ready for the season.
 
OK so this little bike is pretty finicky. I road it to work, the exact route I did yesterday and after the adjustments to the carb when warm it's way lean, I was cruising at half throttle about 40-45 MPH and got a sudden loss of power, shut her down, let her cool, moved the needle to the richest position to be safe. after 5 mins I fired it up and got to work but the exhaust has a steady burble now? no backfires and WOT is still no good. I am going to richen the mixture screw back to the 1 3/8 turns and raise the float a little. I guess I need to pull the carb and measure it. Going to bring it in tonight, let it cool down, then check valves, points, float height, jets for signs of wear etc. I read a few of these little carbs can get worn needle jets that cause issues. I'll get there, it's fun little bike though so looking forward to having it sorted. I also tried adding choke to see if it ran better or worse and it didn't seem to do anything?
 
Found this:
Also probably want to check your valves to make sure theyre in spec, the 125 motor needs adjustment every 500-1000km or so, and they need to be exactly in spec otherwise it runs like ****. Even 1 thousandth off makes a huge difference. I don't remember if I checked them dammit. I meant too. on the list for tomorrow when it's a cold engine again
 
Ok floats were 26mm reset to 24mm per spec. Cleaner comes out of all the air circuit. I found a newer cleaner 105 main jet and swapped the. Set the needle one leaner than if was. Will check valves tomorrow eve and see how they sit. One a side note the pla printed speedo disk warped in the sun and is shot. Will need to reprint in abs
 
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