1971 R/75 issues/Timing help

[bigvic54]

I have a 1971 R/75. It has good compression. strong spark and fuel in both float bowls. However, it won't start. I tried starter fluid but got no combustion.

I thought the problem might be timing so, following the manual, I attached a contimuity tester to the condensor and a ground. Based on the manual the tester should buzz when the points are closed but it buzzes constantly. Why would it do this? Additionally, if there is something wrong why am I getting spark?

Any advice would be appreciated.

 

[20774]

I suspect your tester is connected wrong, buzzing all the time. That indicates the points are closed but yet you are getting spark. Another place to monitor would measuring volts coming into the left hand coil. Tap into the terminal to the coil. 12v indicates points closed...0v points open.

Another way is to remove the plugs, insert back into the high tension leads, and lay the plug threads on the engine fins...threads must always touch the fins for proper grounding.

Turn ignition on but don't go to start mode. Turn engine over by hand (trans in gear and turn the rear wheel) and wait/watch for plugs to spark. Where is the timing mark when plugs spark? Adjust timing as needed.

 

[pauls1150]

Another possibility is that the condenser (aka capacitor) is partially shorted internally, or "leaky", or that the wire to the points & condenser is damaged. Pretty easy to squash the insulation where it goes thru the outer housing.
Also, the points mounting hardware could be touching ground on one side.
These may be intermittent and you'll still see "some" spark, perhaps not as strong as it should be, especially under load and/or when the engine is vibrating.

 

[RPGR90s]

I have a 1971 R/75. It has good compression. strong spark and fuel in both float bowls. However, it won't start. I tried starter fluid but got no combustion.

I thought the problem might be timing so, following the manual, I attached a contimuity tester to the condensor and a ground. Based on the manual the tester should buzz when the points are closed but it buzzes constantly. Why would it do this? Additionally, if there is something wrong why am I getting spark?

Any advice would be appreciated.

And you've verified that both choke levers on the carbs are moving when the lever on the side of the engine is engaged?

 

[bigvic54]

And you've verified that both choke levers on the carbs are moving when the lever on the side of the engine is engaged?

Yes