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Discussion Starter · #1 ·
Hey, I had to rebuild this bike twice now. The first time I rebuild it, it ran great but had an oil leak out the back of points cover and I somehow bent a valve and had to tear down again.

Ok, so When I did the valves, I installed a new valve guide, honed it properly, and made sure all the valves seal. I timed the cam chain on a non-compression stroke, which I asked and researched if it was ok. I don't know if this has anything to do with the problem. I got it all together and the left cylinder is not firing properly. I unplugged the right plug wire and the bike ran on the left cylinder.

I can still feel exhaust pressure a bit from the left side a little bit and it's also leaking gas from the exhaust. I doubled checked the ignition timing on the left cylinder, it's dead on.

I have the bike upgraded with air pods and it's straight piped. To compensate I upped the main jetting to 145 from 140. I had it at 150 and it was too rich.

Any advice or help would be really appreciated!
 

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As Steve (66sprint) so correctly said recently, there is no compression stroke until the cams are timed and the cam chain is connected - there's either LT or T, and with the crank at LT you line up the (correct, as sometimes there are "ghost" marks) marks on the cams and connect the chain. If you had a leak from the seal behind the points, you may have excess wear on the left exhaust cam bearing surfaces. If it runs on the left cylinder with the opposite coil, then it would seem there's at least enough compression on the left cylinder to make it fire. Since you mention fuel coming out of the exhaust, it's possible that's just from not firing consistently, or you may have a float level or other fuel issue in the left carb. Also, I wouldn't necessarily say the bike is upgraded by using pod filters... CV carbs are notorious for not performing properly with non-stock air filters and straight pipes, it can be quite the chore to get it running like stock (or better, if that's what you're trying for)
 

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I would argue that it's not an upgrade going to pods. You will be hard pressed to get the same performance out of the bike running on pods versus with the OEM air box.
If you still have the stock air boxes then try putting them back and see how she runs.

Another issue here being the straight pipes. That's not really an upgrade either in my opinion.
These engines require quite a bit of back pressure to run properly so unless you really baffled the pipes, chances are likely you don't really have any back pressure at all.
How was the bike running with stock pipes and mufflers?
 

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Discussion Starter · #5 · (Edited)
These engines require quite a bit of back pressure to run properly so unless you really baffled the pipes, chances are likely you don't really have any back pressure at all.
How was the bike running with stock pipes and mufflers?
Well responding to the first guy, the leak behind the points was from where the wires come out, I forgot to fill that hole with ultra black. I thought the gasket to the whole cover was leaking which lead to disaster. The bike did run decent being straight piped and the pods added. I like the look of the center behind the engine being cleared out. It also ran fine with the stock airbox and mufflers, it just had little compression on one cylinder which lead me to replace the rings.

I forgot to mention there's a major exhaust leak as the equalizer between the pipes is apart and needs welded up. I don't know if this enough to make one of the cylinders run weak?

If it runs on the left cylinder with the opposite coil, then it would seem there's at least enough compression on the left cylinder to make it fire.
The left cylinder fired with the left coil not the opposite.
 

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Wait what? You had a leak from where the wires for the points come out? There shouldn't be any leak at all, hole or no hole. There shouldn't have been any oil there at all.
Why would you need to use ultra black to fill where the wires exit from the points cover?
 

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^^^yeah, what he said - that's why I mentioned the oil seal on the exhaust cam, inside the housing where the points are and behind the advancer unit that opens the points. Seal up the hole where the wires are coming out and eventually inside the cover will start filling up with oil...
 

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If the cam bearing gasket was leaking, it would likely be coming out around the back of the cam bearing assembly where it meets the head. If it's coming out of the hole where the points wires come out, it's coming from inside the cam bearing/points housing and could be the seal around the end of the cam behind the advancer unit
 
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