1969 Commando 750 will not start

I have a 1969 Commando 750 with a 34vm Mikuni carb and can not get it to start. Never had an issue starting this notton before and always started on second or third kick even after winter storage. Last fall I drove it to the storage garage and when I stopped it seemed to be revving high. I shut it off and then kicked it back over to start, gave it a rev and then it idled down and I turned off the fuel and let it run out of fuel. Came back in the spring fired her up on third kick let her warm up and drove home 6km. Next day it will not start, took out plugs and the tips were white. I know white is not a good thing. did a compression test and both cylinders were 135psi. It does seem a bit hard to kick over but maybe thats just because I have never had to kick it so many times lol. I did drain the oil out of crankcase and pour back into oil tank.
Bought new plugs and new battery (just to rule out a battery issue for starting) and still will not start. have spark although it might be weak but I am not really sure. Thinking carb issue?

Any advice as to where to start is helpful.
Cheers,
Ekvin

"Next day it will not start, took out plugs and the tips were white. I know white is not a good thing."
No longer relevant data.


Troubleshoot


SSBB


SPARK? Plug laying on the head...

Teaspoon of gas in each cylinder, does it fire a few times?

Report back.

I got one running recently that just needed more fuel. Are you kicking with the throttle CLOSED?

concours said:

"Next day it will not start, took out plugs and the tips were white. I know white is not a good thing."
No longer relevant data.


Troubleshoot


SSBB


SPARK? Plug laying on the head...

Teaspoon of gas in each cylinder, does it fire a few times?

Report back.

I got one running recently that just needed more fuel. Are you kicking with the throttle CLOSED?

Click to expand...

yes kicking with throttle closed. Never kicked it over with throttle open in past but will gave that a go. Will try a teaspoon of gas in each cylinder tonight after work. thanks!

Fuel drained from tank or just from carb during storage? Perhaps fuel has gone bad in tank, clogged the flow out of tank? Perhaps you have a seeping petcock the let fuel back into carb and then it sat and clogged up jets?

Ekvin said:

yes kicking with throttle closed. Never kicked it over with throttle open in past but will gave that a go. Will try a teaspoon of gas in each cylinder tonight after work. thanks!

Click to expand...

Mikuni enrichener system only works when there is sufficient vacuum.

I am not suggesting you open the throttle.

"White plugs" are DRY as well, I assume?

Suggests the engine needs gas to fire.

To OPEN the throttle would be used to clear a flooded engine.

Oh, a '69, so fibreglass tank? The resins do dissolve in modern fuels, leading to carb jet clogging.

Tornado said:

Oh, a '69, so fibreglass tank? The resins do dissolve in modern fuels, leading to carb jet clogging.

Click to expand...

...and "hang throttle".

OP, was Ethanol fuel used for storage?

concours said:

...and "hang throttle".

OP, was Ethanol fuel used for storage?

Click to expand...

As per his icon details, he is in Ontario and Ethanol to 10% is now required in Canada at all stations, all pumps.

Tornado said:

As per his icon details, he is in Ontario and Ethanol to 10% is now required in Canada at all stations, all pumps.

Click to expand...

Thank you very much for responding.

My method to troubleshoot starts with the test to determine which of 2 ways to go.... Those ways being fuel supply or ignition issues.

Concours says, "A teaspoon of fuel". My method is to use a squirt bottle with an angled straw cap to administer the fuel effectively. I lift the throttle (slides), and give a shot of fuel into each carb. Then you kick the bike over. If the bike fires up, you know your issue is fuel delivery. If you get nothing, then begin to troubleshoot your ignition/electrical testing.

The reason I advocate the squirt bottle is you shoot the fuel right into the intakes if you lift the slide, so the result of your next kicks pretty much tell you which way to go...

concours said:

Mikuni enrichener system only works when there is sufficient vacuum.

I am not suggesting you open the throttle.

"White plugs" are DRY as well, I assume?

Suggests the engine needs gas to fire.

To OPEN the throttle would be used to clear a flooded engine.

Click to expand...

yes plugs were dry and white

Ekvin said:

yes plugs were dry and white

Click to expand...

Clearly, no fuel present.
Proceed with the previously mentioned tests.
So, to do a quick test, regarding degraded fiberglass resin, unscrew the Mikuni slide cap, pull the slide out of the carb. Feel in the bore, and on the slide for tacky residue.
That will help us know if there is resin contamination.

Put teaspoon of fuel in each cylinder and it fired up second kick then died. Thanks so much for getting me on track to getting running again! will take off the carb, and pet cocks and check everything as it is the fiberglass tank still. cheers!

Ekvin said:

Put teaspoon of fuel in each cylinder and it fired up second kick then died. Thanks so much for getting me on track to getting running again! will take off the carb, and pet cocks and check everything as it is the fiberglass tank still. cheers!

Click to expand...

Tells us the ignition is viable.

Cheers!

Ekvin said:

Put teaspoon of fuel in each cylinder and it fired up second kick then died. Thanks so much for getting me on track to getting running again! will take off the carb, and pet cocks and check everything as it is the fiberglass tank still. cheers!

Click to expand...

You should also have a long think as to what to do about fibreglass tank and modern fuels. Many report failing with various lining products on glass tanks, but might be worth a try if alternative is to replace tank with metal type. I assume this is a fastback tank? As far as i know, only repro metal ones are from India/Pakistan or potentially Alu beauties from TAB Classics in UK if money is not a problem:

Not bad! Even allowing for shipping, it cost more than that to have my new raw steel Emgo tank prepped and only just acceptably painted. Mind you, I did get it free? with the bike.

Edit to correct the fact that the UK sterling price from Tab Classics obviously comes up higher in $ when converted but still not by a huge amount above what I ended up paying. Knowing what I know now, I may have been very tempted to go for an alloy tank, they look great IMHO.

Doh…just realized they are Fastback style not Roadster. I really should pay more attention.