Hot Restart

[Samer]

I've noticed a pattern for a while now. If I start my bike after a week or two, which is usually the case, it starts up on the first try. Full choke, no throttle. However, today, for example, the weather is very nice so I rode to work, same starting situation. But on my way to lunch, about 4 hours later, I turn the choke on and I hit the start button for a couple of seconds. Then again, then again, and finally it catches on the 4th button press.

Funny thing is my old car with a carb also has a bit of a hot restart issue. For the car, the most likely explanation is fuel floods the carb a little due to the hot mechanical fuel pump. Or at least that's the theory.

So my questions are:

What could be causing this?
Should I have the choke on or not in that situation?
Apply throttle or not while cranking?

By the way, bike is 100% stock with 3300 miles, bought new. Nothing done to it except oil changes and one preemptive battery change. I added some Seafoam a while ago when it wouldn't idle and it cleared things up. I haven't taken the carbs out.

Thanks!

[alex.s]

was it actually trying to start... as in it was cranking but not firing... or was nothing happening

[Samer]

cranking but not firing. I don't think it is the battery because, as I said, after a couple of weeks, in which case battery should be on the weaker end, it starts right up.

[jkv45]

Try backing down the amount of choke, a little at a time, until you find the "sweet spot". I'm thinking it doesn't need full choke in that situation.

Also make sure the hot idle is set correctly at 1300 RPMs.

If you do ever pull the carbs, be sure to remove the caps on the idle mixture screws. Chances are it could use fine-tuning of the idle mixture, which would help it start and run better. Temperature also changes the mixture, so when temps change the optimum adjustment changes.

Make sure the fuel is fresh, and keep the tank as full as possible. Best choice for fuel is 87 octane without ethanol, second best is the lowest octane available without ethanol. Running "Premium" when the engine doesn't need it can make it harder to start.

[Motofool]

Originally Posted by Samer

So my questions are:

What could be causing this?
Should I have the choke on or not in that situation?
Apply throttle or not while cranking?

By the way, bike is 100% stock with 3300 miles, bought new. Nothing done to it except oil changes and one preemptive battery change. I added some Seafoam a while ago when it wouldn't idle and it cleared things up. I haven't taken the carbs out.

Thanks!

Samer,
It is possible that you have a rich mix due to high level of fuel in the bowls.
The way to test that possibility:
When the engine is warm (maybe parked four hours under Florida's Sun), try not applying choke and even cracking the throttle open during start up.

[cbinker]

if it is already warm you don't need choke.

[jkv45]

Originally Posted by cbinker

if it is already warm you don't need choke.

He said 4 hours, so it's not really warm anymore.

I do think most likely it doesn't need full choke at that point though.

[Flying]

My opinion is the same as everyone else's. You probably don't need the choke at lunch time.

Try cracking the throttle a little while cranking if you're still having problems.

[Samer]

Thanks all. Since I haven't adjusted the carbs ever, I'll look into how to do the hot idle setting and work from there.

I'll try no choke on the same day restart. I think if it was that simple though, I probably would have figured that out. I haven't been documenting so not quite sure, but I'll try the no choke and slight throttle method. That should bias the mixture more towards lean rather than rich and we'll see what happens.

Will report back when I've gathered more info

[Motofool]

Originally Posted by Samer

Thanks all. Since I haven't adjusted the carbs ever, I'll look into how to do the hot idle setting and work from there.............

Will report back when I've gathered more info

You can always use the best diagnostic tool that our bikes have regarding proper mix: the color of each spark plug.

Please, see:
http://www.dansmc.com/Spark_Plugs/Sp...s_catalog.html

[jkv45]

Originally Posted by Samer

Thanks all. Since I haven't adjusted the carbs ever, I'll look into how to do the hot idle setting and work from there.

I'll try no choke on the same day restart. I think if it was that simple though, I probably would have figured that out. I haven't been documenting so not quite sure, but I'll try the no choke and slight throttle method. That should bias the mixture more towards lean rather than rich and we'll see what happens.

Will report back when I've gathered more info

You can try, but I would expect it to need some (maybe 1/2) choke after sitting for 4 hours.

If it was 30 minutes (depending on outside temp) it should start without any choke.