another dies at stop light question....

i know there are a lot of threads like this but i read alot of them and none of them seemed quite the same as my situation.

ok so yesterday night while riding home, my bike just kinda died at a stop light. it seemed almost like it was out of gas, but i had plenty in the tank and even tried turning it over on RES but still nothing. after waiting about 20 minutes i was able to get ti started and drive it about 200-300 feet until the next stop light where it dies again. ended up calling triple A and waited almost 1.5 hours for the truck to take me the final 3 or 4 miles home

i rode the bike to work (same route) 8 hours previously no problems. although i did noticed that when at stop lights in neutral the idle seemed high (2-2.6K), when i start the bike it idles around 12-15. after 2 hours of work i took the bike to get lunch only a shirt drive maybe 1 mile round trip. and then the rest of the night it sat until i got off work.

when the bike died it seemed to me to be really hot! like a hot stove hot, can only just tap it with my fingers but not hold them to the engine for any time.


recent work done... valves in check, carbs cleaned and wet set, replaced oil sump, oil change.

 

I was gonna say battery but that wouldn't explain the high revs. This is an interesting one. Hopefully one of the regulars will chime in soon!

 

battery seemed fine but was eventually getting worn out by trying to restart it...

 

Sounds like it's running lean.

 

Some sort of air leak? Maybe as far down as in between cylinder 2&3?

 

how fast were you riding? it kinda sounds like it got overheated....

 

You may not have your Bike actually IDLING as it should.

If there isn't enough FUEL and AIR entering the Combustion Chambers when the Throttles get closed ::: enough ::: to eliminate Main Jet Supplied Fuel ... it stalls-out.

The Pilot AIR Screws (Mixture Screws), ... Need to be adjusted to IDLE the Bike on-its-own ... PLUS enough EXTRA to prevent:
a) Hesitation upon getting out-of-the-hole.
b) Need to Throttle-blip to avoid stalling and get started after stopping.
c) Fuel-starvation stalling-out.

You can "Cheat" your way around it.
a) Adjust the IDLE by roasting your hand and wrist in a reach-in tweak of the worst-placed and non-remote-extended Idle Adjustment Rod.
b) Employ a similar tactic, without blistering your wrist, by using the Cable Slack Adjustment at the Handlebar Control.

Cheating-open the Throttles is only a BandAid fix.
Re-visiting your Fine Tuning is a better solution for the long-run.

 

thanks every one. just to make sure the idle mixture screws are on the top of my minkunis correct? how do i know which ones to adjust, on which carb?

 

Most motors speed up before they rum out of gas. Check fuel valve, line, any filters, vacuum line, and gas cap vent. Maybe open the bowl drains and see if any crud cones out

 

Yes. The Mixture Screws are on the Front of the Carb Bodies.

One of the easiest methods of determining what to do with the Mixture is to "Read the Spark Plug Coloration" -- a "Plug read"

Pull the Plugs.
Line them up 1 thru 4.
One is the left one and so-on.
Take a photo of the Ground Straps, Center Electrode and Insulator.

The Plugs should be about the color of a Brown Paper Bag.
Too light = Needs more Richness.
Turn Mixture Screw OUT --> The width of a Dime ... NOT a Quarter Turn.

Too Dark = Too Rich
There are several factors contributing to too Rich.
If the Mixture Screws are beyond 3.75 Turns OUT ...
Turn the one needing adjustment IN a Dimes width at a time.

Think of a Stopwatch.
One Minute is One Turn = 60 seconds.
While Fine-tuning the Mixture Screws, ...
When you arrive at the window of Fine Tuning ... the Tweak needed to get Dialed-in will be just a matter of a few (3 -to- 5) seconds.
A Tweak.
An imperceptible "Nudge".

 

ok sounds simple enough i will do a plug read and some fine tuning. one more question... what/where are the ground straps, electrodes and insulators?

 

The ground strap is the curved piece that comes up and makes a 90* bend;

over the electrode, which is the little bit of metal that sticks up;

out of the insulator which is the ceramic "cone."

We definitely need to see what your plugs look like.

Also, "on" and "res" are both vacuum operated; if the petcock is suspected of having "operating under vacuum" issues, put it on PRI to test. Also, pop your gas cap when it happens; if the gas cap vent is plugged it can cause fuel starvation as well.

You shouldn't be able to "overheat" a healthy 550 no matter how hard you ride; I run at 80+ mph for extended periods A LOT and the bike doesn't overheat. And once warmed up, the whole motor WILL BE too hot to touch. That's normal.

 

alright i pulled my plug and here are some pic, hope you can see them okay just used my cell phone camera. left to right in the pictures would be the same as is you were sitting on the bike.nothing looked overly sootty or oily, but also they all didnt look like they were burning the same either. these are brand new plugs and have only been used since ive got the bike running (3 or 4 weeks)

 

Your phone pics on my phone look a little rich .

 

They look not only a tad rich but uneven. Either you didn't get the float levels accurately even, or you're still out of sync a tad (which would also square with your other symptoms.)

 

I encountered the same problem just a few weeks ago. I just had the carbs cleaned, and it ended up being stuck valves on the 2 & 3. No gas means high revs and a sputtering stop. After a mo, it started with no issue and ran just fine.

 

ok so ill take a look at eh float levels again and double check everything, try to get them even. how do i make it run less rich? air mixture screws? moving them in or out more, i have them at 3.5 turns out now.

 

Pilot mixture screw "base" setting for the Mikunis is around 2 3/4 ~ 3 turns out. 3.5 will generally put you a tad too rich.

 

oh maybe its 2.5, i guess ill have to check, i couldnt remember exactly so i knida guessed at what i set them at. its probably 2.5 but il double check for sure. so screwing the mixtures screws in with make it burn not so rich then okay.

 

IN leans it out, OUT richens it up.

It's not just a mixture issue though since they're clearly not all even. That would indicate uneven float levels or you aren't quite in sync yet.

 

Should the mixture screw be adjusted after idling, or do you hit the kill switch after a WOT pull?