trouble starting in cold

[Shane nakaya]

I have a 620 with the l20b and in the winter when it gets cold(30 and below) it will not start. It cranks but it sounds like the starter is working much harder and cranking much slower as if it’s under load and the engine won’t start. should I get thinner oil so it’s more viscous in cold or should I upgrade starter. I have seen some run block heaters and wonder if that’s also a viable option.

[Stinky]

30 is not that cold.  My 720 started this morning at 30 and has started below 10....but it won't warm up when it gets that cold (a dif-issue). 

 

What oil are you using now?  10-30 is plenty thin....at least according to Nissan.

 

I'd check your connections for corrosion and get my battery checked.  But, after re-reading your post, I see where it cranks fine, or does it?

 

Does your choke close?   Are you pumping the pedal?  At that temp, w/o pumping the pedal, my 720 starts only when warm.  When cold, I have to pump it a couple of times, and then re-start it, pumping the pedal each time.  If I've pumped it, it pretty much starts right up....continued running is a dif story.

[datzenmike]

All carburetors need at least one pump of the pedal to release the choke so that it closes. As it gets colder two pumps and colder still even three pumps. Each pump forces the accelerator pump to squirt raw fuel into the intake.

 

10w30 is good down to 0 F. I wouldn't use anything with 5w in it.

 

Batteries get weaker as their temperature drops. I remember my neighbor taking his 6v VW battery out and putting in his oven on really cold mornings. Have your battery tested for draw. It should be capable of delivering several hundred amps specially when cold. They don't last forever. A poorly tuned engine is also a hard starter.