Hope you're all having a great Memorial Day weekend!
I had some time to troubleshoot the bike and here are my latest findings.
Please let me know your thoughts. Where do I go from here next?
- As per @murrayf 's advice I checked and made sure the throttle and choke cables are connected properly and not pinched anywhere making sure the throttle could freely move and seat at the bottom.
- I tightened the hose from the petcock because I noticed a leak - and not from the left carb bowl (as I originally thought) - note to self: make sure to tighten the fuel hose clamp after installing the tank.
- I adjusted the idle speed by turning the black knob. (It did not need a lot)
- I ordered and installed new o-rings for the intake to make sure there is no air leak.
The result was encouraging, the bike idled well with no choke, and it seemed both cylinders were running, when I checked by pulling either plugs althought, the left cylinder ran much weaker. (See video
I went for a spin, but it immediately felt like it's running only on one cylinder as soon as I started going. The bike had no power and needed to give a lot of gas revving to 4k, just to get moving, and it was only accelerating on one cylinder. I pulled the plugs to see while moving, and found the left cylinder was not running. The bike still idled fine though.
In my original posting I am referring to an intermittent cylinder issue. At first the second cylinder would catch on at higher RPMs, but now it does not anymore.
After this ride, I did the following tests:
- I checked for spark, by pulling the cables from plugs on both sides while running (as per my video)
- I pulled the plugs and while the right one looked good, the left one was oily and black indicating it's getting fuel but not running.
- I swapped the coils to check if one was not working, but it made no difference. The left cylinder was still the one not running. (I swapped them back)
- I cleaned the connectors from the CDI in all 3 clusters.
- I checked the stater resistance values against the Haynes diagram and the numbers look good. (See below)
1/5 - 116 (normal range is 95-116)
2/5 - 98 (81-99)
3/5 - 212 (185-225)
4/5 - (95-116)
6/5 - 99 (81-99)
7/5 - 215 (185-225)
8/9 - 88 (77-95)
5/9 - 360 (387-473)
Keep in mind the carbs are stock and just got rebuilt by Murray.
Some additional notes.
I also noticed a lot of smoke behind me on the road (probably the unburned fuel from the left cylinder). It still runs on one cylinder but seems to idle well on two.
I have been doing some research, and I have a sinking feeling that this might be a CDI related issue. I have also been researching options, for repairs and it appears the options are limited.
Looks like the pit bike coils are cheap enough and easy to replace, so it might be worth a shot, just in case but at the end it sounds like a CDI thing. ... again, open to your suggestions and comments.
I also measured the coils' resistance.
Left coil: 766
Right coil: 802
It appears they are also within the acceptable range, so no replacement is necessary.
Keep thinking CDI... thoughts?
Thanks in advance,