1977 XS360 won't start

[dwray]

Okay so about a week ago I bought my first yamaha... a xs360, I've had a few other bikes and am relatively familiar with the process of fixing them and within a week or two i'll be riding down the road. However, this story's a bit different. I can't get it to pop at all with the kick starter, but If I pull it down a hill with another bike at about 20-25 mph then pop the clutch it will pop a couple times then just slow to a stop... I've done everything I can think of, so any input would be great.

Ill make a list of everything I've done, let me know what I should do next.

- 150 psi compression
- Carbs cleaned, dissected and put an ultrasonic 3 times each without diaphragms in them.. diaphragms checked out and working
- New spark plugs
- New points, set to gap to 14 I believe
- Adjusted timing
- Unclogged exhaust pipes... mice thought they would be a good place for a home.
- Replaced fuses
- Cleaned gas tank (no water or anything, just drained and used compressed air)
- Adjusted valves to spec

In recap, I have compression.. I have spark.. and I have fuel (not sure if carbs are working, but carb cleaner sprayed directly into cylinder should be sufficient for about 2 seconds of running) I'm stumped, anyone encountered anything like this before? Anything obvious I'm missing?

 

[dwray]

UPDATE: Turned the points 180 degrees and bike fired right up... so my points are now upside down but bike runs, not sure what's going on where my points need to be upside down... did I just mess something up in the wiring?

 

[spectra]

UPDATE: Turned the points 180 degrees and bike fired right up... so my points are now upside down but bike runs, not sure what's going on where my points need to be upside down... did I just mess something up in the wiring?

I am not a points guy as mine are gone and run a Pamco but it does state one set of wires goes to one side and one set to the other...........

Not sure if the points are the same or ?

 

[dwray]

Have the wires hooked up right I believe, maybe i'll switch them around to just give it a try.... I've taken the points plate off and turned the cam 180 degrees and no matter what the spark fires at the end of exhaust stroke and beginning of intake stroke... while both valves are slightly open

 

[dwray]

Turns out the problem was the cam lobe that opens and closes the points was flipped 180 degrees... not sure what moron took it off and did that but t made my life incredibly hard lol. Anyways, after hours of scratching my head at how my timing could possibly be 180 degrees off I finally went screw it and took everything apart and took the points plate out and put it all back together correctly and it worked. In case anyone else has this same problem... doubt they will but there's the solution

 

[Winnipeg_79_XS400]

Turns out the problem was the cam lobe that opens and closes the points was flipped 180 degrees... not sure what moron took it off and did that but t made my life incredibly hard lol. Anyways, after hours of scratching my head at how my timing could possibly be 180 degrees off I finally went screw it and took everything apart and took the points plate out and put it all back together correctly and it worked. In case anyone else has this same problem... doubt they will but there's the solution

Hey dwray

I may be suffering the same cam issues. Dose this look familiar

 

[Winnipeg_79_XS400]

Yup. 180 off

 

[Winnipeg_79_XS400]

What's left of the bearing

 

[xschris]

That's the cam seal. The cam rides on plane type bearings that are made up of the head and rocker box.

 

[Winnipeg_79_XS400]

That's the cam seal. The cam rides on plane type bearings that are made up of the head and rocker box.

I think you mean "was" Chris LOL. Do you happen to know what size bearing/cam seal that is?

 

[xschris]

It's just a seal there aren't or was any bearings up in there. The top end of the motor is under high oil pressure. The cam rides on a thin film of oil between the head and rocker box. That's the bearing. ( plane style)

 

[Winnipeg_79_XS400]

It's just a seal there aren't or was any bearings up in there. The top end of the motor is under high oil pressure. The cam rides on a thin film of oil between the head and rocker box. That's the bearing. ( plane style)

Thanks for the info! I'l order one and button it back together. Ordered a PAMCO electronic ignition for it! Can't wait!

 

[NewHavenMike]

Youll be very happy with the Pamco. You will need to make up connectors to install it so get your wiring tools out. I soldered my connectors and used heat shrink tubing. Theres plenty of wire on the unit and I need to redo it all once I get the rest of my electronics and everything has a permanent place.

 

[Winnipeg_79_XS400]

Ya, i read on here (somewhere) never half-ass wiring! Ill be making a new wairing harness myself after my 650