Hard starting after sitting revisited

[TripleKing]

My 89 750 Kat has difficulty starting after sitting a few days. In the warm weather, say above 70 degrees, it will start fine if it sits no longer than three days. Below that, even a two-day spell will render the Kat unable to start. If I continue to try, fuel floods the engine and I get a loud bang out of the right pipe. Temperature only effects the time required to sit before I have a problem.


The last time. I road the Kat was last Friday. It would not catch on Sunday. In July, I went on vacation. And the Kat sat for 10 days (on a battery tender all the time). It started, but would only run with the choke on. After the bike ran for about 30 minutes, it ran normally. If I use everyday, I never have a problem starting, even below freezing.


I am thinking it is water in the ethanol laced fuel that is the culprit. I have tried different additives, including Sea Foam, but. Nothing helps.


My three other bikes also have difficulty after sitting a few days, but not lime the Kat. has anyone here had a similar issue?

[katanarider]

Mine does the same thing. I don't know what does it. I figured its because I have pod filters , ethanol gas or unprimed circuits or something. Its pretty much been like that since day one (had pods since day 2 ) Even after 2 carb rebuilds in 7yrs by professionals. I turn mine over on choke a few times, if it stumbles even once at all I turn the choke off to clear the cylinders on 2nd attempt. 3rd attempt, re-choke it and that usually starts it. Today it was really being difficult after the hurricane and cold temp weather. Good thing I have a new battery. I usually start my bike about once a month to keep the carbs primed/unclogged with ethanol.

[TripleKing]

Mine does the same thing. I don't know what does it. I figured its because I have pod filters , ethanol gas or unprimed circuits or something. Its pretty much been like that since day one (had pods since day 2 ) Even after 2 carb rebuilds in 7yrs by professionals. I turn mine over on choke a few times, if it stumbles even once at all I turn the choke off to clear the cylinders on 2nd attempt. 3rd attempt, re-choke it and that usually starts it. Today it was really being difficult after the hurricane and cold temp weather. Good thing I have a new battery. I usually start my bike about once a month to keep the carbs primed/unclogged with ethanol.

I have the OEM air box and mine does that after a couple of days.


Problem is not the carburetors. bike runs great and starts fine if ridden regularly.

[H-2 CHARLIE]

Weird

[jbo197]

Ethanol gas gums up when sitting with these bikes ...

[TripleKing]

Ethanol gas gums up when sitting with these bikes ...

I know, but it takes so little to cripple the Kat. Adding ethanol treatment to fuel, this evening and we shall see what happens. Fuel was purchased last Friday morning.

[1LE]

I have the same problem and gas treatment doesn't seem to have any impact.

[TripleKing]

Mine does the same thing. I don't know what does it. I figured its because I have pod filters , ethanol gas or unprimed circuits or something. Its pretty much been like that since day one (had pods since day 2 ) Even after 2 carb rebuilds in 7yrs by professionals. I turn mine over on choke a few times, if it stumbles even once at all I turn the choke off to clear the cylinders on 2nd attempt. 3rd attempt, re-choke it and that usually starts it. Today it was really being difficult after the hurricane and cold temp weather. Good thing I have a new battery. I usually start my bike about once a month to keep the carbs primed/unclogged with ethanol.

I used your starting "procedure" ands she started. There was so much water vapor coming out of the exhaust it looked like a steam engine.

[katanarider]

Was it cold out ? You'll notice the steam when its cold. If it wasn't you may be over heating/heating too rapidly. Maybe someone more educated about humidity and tuning will speak their opinion here
Anyway, I've kind of put more thought into the hard starting issue that alot of people seem to have. I've come up with this...Maybe sitting side ways on the kick stand is starving cylinders/carbs 3 and 4 of fuel. In other words it drains out. Also, 1 and 2 carbs are then flooded. I don't know really, just a thought.

[Kreylyn]

My 89 750 Kat has difficulty starting after sitting a few days. In the warm weather, say above 70 degrees, it will start fine if it sits no longer than three days. Below that, even a two-day spell will render the Kat unable to start. If I continue to try, fuel floods the engine and I get a loud bang out of the right pipe. Temperature only effects the time required to sit before I have a problem.

A few things come to mind here.

First, the most likely answer for the hard start issue (since temp has an effect on it) is low voltage at the coils.

This doesn't mean it's the only issue. It's definitely a major one that may be pointing out other issues.

Your coils will need a minimal of 11v for them to spark the plugs hot enough to start a cold engine. The colder it is, the hotter the spark that is needed.

You could simply have a week/failing battery, a/some wiring connection points causing a loss, or poor grounds.

I'd suggest you check the voltage at the coils. Do this by pulling the tank off (your not trying to run the bike, so fully off is fine). Test the voltage at coils and battery with a volt meter. Check the following 3 ways.

Power off.
Power on.
Starter turning the motor over.

Differences in numbers here will paint a very clear picture for you.

Krey