Cold Starting??????????

[Johnniethefinger]

Finished bike on Sunday, started up for first time in warm garage on 5th pull. Did some chain adjustments and went for a cruise, about an hour. Work fine started several more times no problem. Let bike sit overnight, in the morning temp was about 20 degrees Fahrenheit. Do you think this would start with out a couple shots of either. I checked everything, spark fuel air. I am running a mix of 16:1 fuel 91octane and good oil. Manual stated this ratio, seems kinda thick. I pulled the plug, it was wet. Has great spark. Gas on plug would not light with a match. Once it started on either it was fine. Any ideas?

 

[arceeguy]

Maybe the high octane fuel had something to do with it. The higher the octane, the harder it is to ignite. You might do better with the cheap stuff.

 

[motorpsycho]

did you try the choke?
generally, gasoline on a spark plug will not light with a match.
if it'll run on ether, it should run on gas. but you may want to go down to 87 octane.
plus, with the 16:1 ratio, it will be tough for the plug to ignite the fuel in cold weather.

 

[AussieSteve]

What motorpsycho said.
(The choke is down when off and up when on. Some people aren't aware of this initially.)
Try one starting attempt with the choke on, then a second with the choke off.
That seems to be the most reliable starting procedure, for mine and several others' bikes.

On the 16:1 ratio thing, I was already wondering if fuel/oil ratio would affect starting.
On my mower, at least, I usually use 50:1, but had some old 16:1 left-over from MB run-in and used it to mow the lawn today, (mid-Summer here). The mower started as easily as usual, in fact it only took 2 pulls, usually 3.
Still, in general, does fuel/oil ratio affect starting? It sounds like low octane is best for starting, but higher octane is better for running.
I ask because I'm running a high-comp billet head from RSE and a shift kit from SBP, (not quite fitted), and am running 20:1 at 98 octane. Will it be harder to start when I'm done?
(With the shift kit, I can no longer 'bump' start and must pedal. I'll consider dropping the octane rating slightly if it will make starting easier. (I kick-start on a stand. So far, in Summer, it's been OK.)

... Steve

 

[Johnniethefinger]

I am going to try a different fuel ratio, also I think the carb might have some dirt or particles in it from shipping. I took out the throttle barrel, checked the needle and put back in and it started. Not sure if there something stuck in the jet well or not. My son and I will take it apart this weekend. But I am going to change the mix to 32:1.

 

[motorpsycho]

when you have more compression, you need higher octane fuel to make it run good and to reduce pinging (spark knock).

 

[wackyimagaintion]

vary imformitive imformaition i'm haveing trouble with my new engine becouse of the weather i tookit out to day for the first time and after a months it startes and stop running in 3 hours lol what the heack .. owell somthing for me to work on tomorow lol ....

 

[AussieSteve]

when you have more compression, you need higher octane fuel to make it run good and to reduce pinging (spark knock).

Yep, that's why I use octane-booster to raise the rating from 91 to 98, to suit the hi-comp head.

I'd assume, though, that the higher rating should, in theory, make the engine harder to start since the fuel is less volatile.

... Steve

 

[Johnniethefinger]

Heres an update, I changed the ratio from 16:1 to 32:1. Now it starts on the second pull, and runs smoother. Thanks for the help.