Hard to start at 25 degrees F

[stroutmail]

Car started OK in warm 50 degree shop.   Moved to unheated shop and would not start.
Has spark and fuel at carbs.  (Fuel from Summer so not winter blend)   
Plugs not new--dark color but dry.
Tried with choke rod pushed back no throttle.  Also tried with part thottle.
A couple backfire pops in header but no luck.
Stopped--did not want to wear out starter.


Next step would be to change all plugs.

Can these things be started at 25 degrees F???

[justfreaky]

I don't start so well in 25 degree weather either. lol!
Give it a shot of quick start. Should fire right up. Give it a few minutes to warm up. Should be fine.
New plugs would hurt anything.  Dump the old fuel also.

Steve

[rob]

drain carbs add fresh fuel, depending how long sitting the corn mix does not last long,
 you may have to pull the carbs and clean bowls and needels with carb cleaner.

[VMS Motorsports]

if the battery is weak, and you have 20w50 oil, it may also not spin over fast enough

[stroutmail]

I've done all of the stuff you would do for an automobile racing engine--including a shot of ether (quick start).   As I said, it has spark at plug and fuel at carb.
What I am not familiar with is these carburators---not much like a four barrel holley double pumper!   As I understand it, the choke is really not a choke butterfly but some form of fuel enrichment system that I don't yet understand. 

Car cranks like it is starving for gas, but plugs are wet. 

Was trying to get a feeling for whether these engines are tough to start in really cold weather.  I remember my 250 motorcross bike would not start in the winter 0when it was cold without pushing it in gear.   

I'm thinking problem is a combination of old plugs, old gas, old battery and very cold air.   Had not thought of the bad fuel in carb bowls. 

Noticed battery ground is only run to battery holdown and not run directly to starter as I have been taught is best practice.  This would cause battery cranking voltage to be weaker than optimum--slow cranking and low starting voltage.

I think by the time I figured out how to activate choke system manually (it does not have cable) the plugs were too wet and the battery was too run down.

Will attack problem again later this week. Expecting 50 degrees on wednesday?   

[csm14701]

A few things.  If you ran pump gas, it likely contains a small percent of ethanol.   Ethanol is very susceptible to condensation.  Thus being like 10 degrees, the fuel in the carb may be partially frozen.  This can make to floats stick causing no fuel or to much fuel.  If the engine is older, and there was to much fuel it may have flooded the engine. The cylinder walls may have gotten washed down with fuel.  To much fuel can cause a lack of compression and may not fire even with quick start.  Quick start fires with a combination of spark and compression.  If the plugs are to wet to fire, and a lack of compression, quick start may not help.  The compression will come back if the cylinders are washed down.

[stroutmail]

I think your comment about old fuel having frozen moisture is very insightful and wise.  It certainly would help explain the "weird" behavior of the engine.  (Not only was it cold, but car had been "cold soaked" in it by being towed in an open trailer for 50 miles before I tried to start it.)  Your explanation of why ether may not help is also quite insightful. (Starting a "flooded" engine is difficult not just because of wet plugs--also a lower compression with no oil on the rings.)   Engines, carbs and fuel supply require attention to detail when not started for some time and cold temps make problems more evident.

Any suggestions for reference material to help me understand these carburetors---they seem to be a Japanese copy of the old SU carbs run on British cars. (The SU carbs were quite tempermental but worked well when properly set up.)

This challenge is a good learning experience.  To go fast, you need to understand the machine completely.

Thanks!

[Richie25x]

Had the same issue for turkey derby at the end of the year.  Took us 4 hours to get motor started. Did everything mentioned above and then some.
It will take a long long time to start.  We changed carbs same issue. checked over coil and box. Had spark at plugs. Changed plugs and almost changed whole igniton system lol.
Motor was flooded but eventually got it to start after 4 hours of trying. Cleaned of contacts on pick up then it fired. Once you get it started keep it running at idle for a while. 
It will crank over every time after that.  Ran pump gas so i am assuming thats where all the water came from that was shooting out of the exhaust when we got it started.

[knoxracing]

I wiil tell you i had a motor recently that was stored in a cold enviroment. My customer tried to start it as you all have done, same results after changing everything you guys tried. The motor was brought to me, we pumped it and it was terrible. We blew compressed air into the cylinder, put a little penetrating oil in the cylinders and turned it over. It fired after a couple minutes. We ran it for a while shut it and shut it down. The compression came back although I will say it was weak but alot better than before. Bottom line, the motor had a stuck ring or valves tha were not working properly. I suggest removing the plugs and carbs before injecting the forced air . i would for sure change theplugs and fuel.

[stroutmail]

Just some feedback---we got a heat wave here today above 55 degrees.  With full choke and no throttle, engine fired on first crank and seemed to run perfectly.
Seems like the "choke" is pretty important as in order to keep it idling smoothly, I gave it partial choke, gradually reducing until it warmed up.

[csm14701]

Also maybe some useful information.  I used to work for my uncle at his gas station.  They had 3 tanks in the ground.  One for 87, one for 89 and one for 93 octane.  Some stations use 2 tanks 87 and 93 and mix them for 89.  There was a electronic tool that read fuel and water levels in the tank.  The 87 always had about a foot of water in the tank.  The 89 had about 6 inches in the tank while the 93 usually had about 1 inch in the tank. Just food for thought.  So it is true, do not fill up while a tanker is refilling the tank.