Does power cut out when it shuts off? How quickly are you able to restart the bike?

Arnold wrote on 08/04/14 at 09:26:23:


The best I can explain it is its as off you turned the choke on a small engine that's hot.  It suddenly starts chugging and coughing.  I can keep it running for about 10-20 seconds by keeping full throttle, but then its done.  Also, it will not restart until the bike cools down.  Usually it'll be at least 20-30 min before it'll start, but if it completely cools its a sure bet it'll fire right up.

Pull the plug, what color is it at the ignition end?  Better still, post a photo.

Alright guys, I finally was able to get home from a camping trip and try a few things.  First, I held a clear tube on the bottom of the carb bowl and let the fuel drain into it.  Holding it upright, I was trying to see how far up in the bowl the fuel was coming.  I wasn't able to get a real good look but I felt that as before, when I held the floats/carb into a bowl of fuel, the fuel is getting to about 1/4" shy of the mounting flange of the bowl.  

After this, I then tried removing the fuel line from the raptor petcock, and then blew into the fuel line.  As the floats reached the mid point of total travel, air flow started to become restricted.  Slightly past the mid point, I was not able to blow any air at all into the fuel line.  I feel quite confident the new needle/seat that I installed is working properly, also it wasn't a cheap aftermarket, I installed an OEM part.

I then also had stopped at the power sports dealer near by and picked up a new NGK spark plug.  I figured for $3, why not.  I took the new plug and found the correct sized deep well socket.  Then with an extension I reached down in to loosen the old plug and holy crap, it was VERY loose already!    In fact it was so loose that I couldn't even use the ratchet, and had to use my fingers on the extension.  

The old plug looks rather black/fouled as to be expected, with the remainder of the plug looking normal.  Although everyone says its a fuel issue, and I believe it still may be, I am hoping this is the actual cause.  Is it possible it started to miss fire from the super loose plug, but since the engine was still turning/pumping air, fuel was being sucked in and not burnt until it finally flooded itself out?

With so much screwing around with this bike the already old/used up battery finally has taken a dump.  Unfortunately I wasn't even able to start it to try the bike.  I'll report back tomorrow after I get a chance to get a new battery and install it.

Aaron

FIXED!!!  Well it turns out it may have been one little thing, or a combination of issues all working against me!  I guess that's what you get buying a used bike with unknown history.

Today after I readjusted the floats again, the bike seemed better, but I still was getting some oil/fuel in the black drain tube at the bottom of the bike.  I decided since I've done a number of test runs that I should change the contaminated oil.  I planned on doing this right away, however I didn't want to change it and then recontaminate it with flooded fuel.

Looking into the sight glass the oil level was full.  As I removed the drain bolt, I couldn't believe my eyes.  I would guess AT LEAST 2.5-3 quarts came out.  Either someone didn't know what they were doing and decided to fill the bike full of oil, or that much fuel had gotten into the crankcase initially with the flooding issues.  Either way after filling the bike to the mid point between the two lines on the sight glass, I took it out again.  

This time not only did the bike fire right up, it sounded crisper, idled smoother, and even after being warm, the idle would stay at the same point, previously it would slowly get lower until it started to foul/act up.

I put about 10 miles on it so far at city speeds to highway speeds.  It starts right up when warm, (before it wouldn't), and now the only issue I have is a small occasional backfire when I have a hard downshift/slow down.

In conclusion, maybe it was to much oil in the first place causing all the issues?  Maybe the needle/seat were leaking also as the new one did seem to help, maybe it was the ultra loose spark plug I found that lowered compression slightly making hard starts?  Who knows, all I know is I now have a good running and good looking S40 with only 1600 miles on the clock!  

Thanks for all the help and input everyone!

Aaron