Topic: CB500 1972 hard starting cold. Update 10/19

[drodg33]

My bike is a mostly original 72 CB500.  Stock carbs, exhaust etc.  It has 18000 miles on it.  Runs very nice no hesitation once warmed and idles around 1100 rpm when hot.  But....it has always been hard to start, cold.  I have to turn it over maybe 15 times for it to start with the choke fully on and giving gas off and on through that sequence.  Starts great hot.  Any suggestions? 

[calj737]

When was the last time you cleaned the pilot jets and emulsion tubes? Also, when cranking and firing, does the motor sound right? Sometimes the timing can be off enough that initial starts are difficult and ignition timing plays a role here. But a full 3,000 Miles Service interval should reveal any contributing factors to a poor starting bike.

[drodg33]

Thanks and it has been a bit.  Idles rough at first but clears off pretty quickly.

[jonda500]

Are you priming it first? Mine fires instantly, but for the first start of the day, before I turn on the ignition, I kick it over with the choke on & the throttle held fully open (2-3 kicks in summer, 5-6 kicks in winter), then I release the throttle, turn on the key and it starts first kick every time! (I have no electric start cause my starter clutch is worn out.)
John

[drodg33]

Are you priming it first? Mine fires instantly, but for the first start of the day, before I turn on the ignition, I kick it over with the choke on & the throttle held fully open (2-3 kicks in summer, 5-6 kicks in winter), then I release the throttle, turn on the key and it starts first kick every time! (I have no electric start cause my starter clutch is worn out.)
John
[/quote
I have never tried that.  I give it multiple throttle applications with choke on and with the key.   My old cars of course that have carbs it is one kick and then turn over. 

[drodg33]

Thanks

[drodg33]

So here is an update on my cold starting issue.  On another string on this forum someone had posted how they start their 500 or 550 every time cold.
1. Open the choke and turn on the gas
2. Put kill switch to off
3. Hold the throttle wide open and hit the starter for five seconds.
4. Put kill switch back to on and give the bike 1/8 throttle then hit the starter button or kick start
I tried this last night after my 72 500 was sitting for over a week and it fired right up.  I am not sure who posted that but thank you it has been the first time I have started my bike in 18 months on first try.  It starts fine hot and runs well after warming up. 

[Deltarider]

A few kicks is enough. The procedure is described in: STARTING IN EXTREME COLD WEATHER in the CB500 Owner's Manual p.29 https://www.honda4fun.com/dwnload/Owners-Manual/CB500-K1-Owners-Manual.pdf Every owner of a CB500 is advised to read carefully the starting procedures.
Whenever my CB500 has stood for four days or longer, I also need this procedure. The reason we need this  more than back then lies in the changed properties of gasolines. 

[drodg33]

Thanks for that and I had never noticed that in the owners manual.  Btw interesting on the gasoline properties now. 

[Deltarider]

Thanks for that and I had never noticed that in the owners manual.  Btw interesting on the gasoline properties now. 

My remark was not very scientific I'm afraid. For me a cold start is a cold start. Yet within three days after the last run, the engine will start immediately. After more days I have to go to the extreme cold procedure. I was curious why this was, so I experimented.
At first I made sure battery was 100% charged. Made no difference.
Next experiment was to first drain the bowls and have them refill with fresh gas. Made no difference.
Meaning the difference between cold starting within three days and longer than three days on the other hand, remained. So I concluded - possibly prematurily - it may have to do with changed properties of the gasolines. But others may know more.

[drodg33]

Thanks for that and I had never noticed that in the owners manual.  Btw interesting on the gasoline properties now. 

My remark was not very scientific I'm afraid. For me a cold start is a cold start. Yet within three days after the last run, the engine will start immediately. After more days I have to go to the extreme cold procedure. I was curious why this was, so I experimented.
At first I made sure battery was 100% charged. Made no difference.
Next experiment was to first drain the bowls and have them refill with fresh gas. Made no difference.
Meaning the difference between cold starting within three days and longer than three days on the other hand, remained. So I concluded - possibly prematurily - it may have to do with changed properties of the gasolines. But others may know more.

I think about as scientific as anyone would be except maybe those who are in the petroleum industry.  Lol.