I surrender

[rickrman]

Will jerk the Pamco and return to two points, two condensers and two coils. THEN I will rebuild the rectifier, regulatoe again, and again. I need sympathy. Anybody want a PAMCO? https://www.ebay.com/itm/305024503800

 

[toglhot]

Why not convert it to single points, single condenser and dual output coil. Much more beterer!

 

[rickrman]

Because if it made sense, Yamaha would have done it.

 

[rickrman]

Engineers are obsessed with simplicity and efficiency. Odds are, Yamaha had it at least VERY close.

 

[Jim]

Why not convert it to single points, single condenser and dual output coil. Much more beterer!

Because if it made sense, Yamaha would have done it.

I can't speak to the engineers thought process, but here's what they effectively built.... 2 single cylinder engines on a common crank.
Consider... each cylinder has it's own carb, it's own point and condenser set... it's own coil.
Fry a coil? no problem, it'll still get you home on one cylinder. Carb goes bonkers? Shut that petcock off and ride it home. She don't like runnin' on one cylinder... but she will.
I once had a set of points go out/fry on me up in the mountains of Idaho. Nearest town was about 20 miles away... home was 30. It got me home on one cylinder. That's gotta be worth sumpin.

 

[Jan_P]

Because if it made sense, Yamaha would have done it.

Well generally speaking you are right The factory do know their job But in the XS 650
The pretty much only thing they got wrong on the Motorcycle was the spring loaded centrifugal advance unit
from steam engine times
With bushing not oiled and no service instructions .
Expensive unit if you don't have one in good order.
The main reason why people mention the Magical words "Boyer Bransden "
As with Britt Bikes I believe
A rainy night in Dakota ..water at the points and the advance unit not retarding.
3 times on the electric starter and it is game over. Can try 3 times with kick starter ,,and then start walking home.
Only joking ..but all in all that stock solution has its problems

 

[toglhot]

Because if it made sense, Yamaha would have done it.

So, you're saying all those car manufacturers that put single points in their vehicles didn't know what they were doing? If Yamaha had wanted to 'make sense', they wouldn't have built a 360 degree twin when all other manufacturers were moving away from them, then there are all the other design flaws on XS650 that don't make a lot of sense: frame, balls in the steering head, starter gear, strainers instead of filters, et al!

 

[Team Junk]

As a fan of aircraft since a young age I appreciated the dual everything. I have one lunged home on a 650 more than once.. I even made it around Texas World Speedway on one lung at a pretty good clip to keep from getting run over.

 

[toglhot]

Engineers are obsessed with simplicity and efficiency. Odds are, Yamaha had it at least VERY close.

What's simpler one set of points or two, balls in the steering head or tapered rollers, one carb or two? What's simpler having to take the motor out of the frame to work on the gearbox, rockers, cylinder head, pistons, and barrel, or, leaving the motor in place and being able to do all that work.
The Japanese had some very good ideas and built some very nice bikes, but they were far from perfect, far from simplicity, and far from efficient!

 

[rickrman]

I can't speak to the engineers thought process, but here's what they effectively built.... 2 single cylinder engines on a common crank.
Consider... each cylinder has it's own carb, it's own point and condenser set... it's own coil.
Fry a coil? no problem, it'll still get you home on one cylinder. Carb goes bonkers? Shut that petcock off and ride it home. She don't like runnin' on one cylinder... but she will.
I once had a set of points go out/fry on me up in the mountains of Idaho. Nearest town was about 20 miles away... home was 30. It got me home on one cylinder. That's gotta be worth sumpin.

Perfect assessment.

 

[650Skull]

When MikesXS first introduced the single point cam I bought one and installed it. Bike seemed to run well, no dramas, I also left the second set of points on the plate. Thought if for any reason the points failed all i would have to do is swap the wires at the condenser/coil and set the second set of points and Bobs your uncle.

It was a while later it was reported the single points, duel lobe cam wasn't exactly even and one side couldn't be exactly timed if the other one was. splitting the difference it worked but the report was it was another failed MikesXS part..........Again i didn't have any trouble with mine

Also when i built the Bridge Rect i used 2 single phase units. This also gave me a spare diode, in the unlikely event a diode shit itself all i had to do was swap the wire over to the remaining good one. Back to full charging

The bike will get you home on one cylinder, that is a good thing. By doing what i have done it also eliminated that issue, especially if you were miles and maybe a day or so away from home. Piece of mind.

 

[Wingedwheel]

Is there any engineer available here??

I heard you were looking for an Engineer?

 

[46th Georgia]

I heard you were looking for an Engineer?View attachment 246902

Wooooo Wooooooooo!!!

 

[Speakas]

So my pamco also probably just fried as well. Bike cut out after less than 2 seconds of firing. Primary coil had 1 ohm of resistance, and my pamco unit green wire is constantly giving 0v, not 12v to 1v as in the other thread. Looked up the transistor that was supposed to work and of course it's discontinued. Too much heart ache now. Might get the trispark system because it's available in Australia, but it is also pricey..

 

[JOHNDADDY]

Points and condenser's. I always liked the way you can tickle each side to it's sweet spot. Same with the carbs. Carried extra condensers in my tool pouch just in case but she will carry you home one cylinder.

 

[hovel]

I always liked the way you can tickle each side to it's sweet spot. Same with the carbs.

Amen brother. No two cylinders are exactly the same, no two carbs are exactly the same. I really like separate adjustable throttle cables as well as the points.
Synchronizing points/timing and carburetors is only the starting point. Find that sweet spot and the vibration doesn't always go away, but it becomes harmonious.