intermittent rough running; hot cat

[MinnesotaRik]

Hi! I am a first time poster-- NOT a mechanic - also not afraid to get some grease under the fingernails

1995 GS 1100
57k miles
Second owner as of 2011
(With SWEET new KTC 80 knobbies! Golly, that looks cool!)
Last oil change last fall about 700 miles ago-- purple stuff, getting supplies together to get the filter and oil changed tomorrow


I got home from a highway ride and pulled into the garage after dark- I could SEE the dark orange glow of my catalytic converter. Are they supposed to get that hot?
I don't remember seeing that before.

It has been running rough since spring start/ like some flake in the injector -
Reminds me of when my old carbu Honda 500 would have some crud in the jet. Give it more gas and it suddenly clears and runs fine but then returns soon. I have already washed the air filter (yes, a K&N), replaced and gaped plugs-- the old ones had thin grey ash on the bent arm and black powder on the inside ring. One of the spark plug leads was not pressed home at first but now is solid- I have burned a tank with fuel injector cleaner- will burn one more before I plan to disassemble the injector area

Seems a little better ...


I had to readjust the clutch handle as I think I have lost another mm of clutch plate from wear--
I don't think the rough running is from the clutch as the roughness was intermittent- and improved after giving more power

So:
1. Cat too hot? If so what does that mean?
2. Ideas on next steps for the intermittent stumble


Rik
In Minnesota- OF COURSE going to the rally!

 

[pbrokaw]

How many miles have you owned the bike???

Is the cat code plug in the fuse box in place or did someone remove it.When it is removed the motronic runs "open loop" with out the feedback from the O2 sensor. A fair amount of folks have done this to help with the dreaded BMW surging at cruising part throttle settings. The side affect is...

More fuel is injected into the engine. And this is hard on the cat heating it up and probably going to eventually plug it up.

The guys that run with the CAT code plug removed are usually running a aftermarket can with a "S" pipe in the place of the OEM cat/exhaust assembly.

My GS is running a Hindle Ti can on it with the CCP(cat code plug) removed. The power with the CCP in or out is about the same.Moto Perf in Middleton did the exhaust work of me(hats off to Bill and the gang their,great folks!!!) Anyhow they did dyno runs with stock exhaust,Hindle installed and Hindle with CCP removed.

I gained 2hp and 2 ft pounds of torgue ,not much to justify the cost of the exhaust... But the bike is about 15 pounds lighter. And it sounds better...A bit too loud,but better with a silencer in the outlet.

For more info head over to the ADV rider site,there is a thread in-titled
Cat Code Plug-CCP .read this for your schooling pleasure .

Good luck and see you at the rally.
Perry

 

[pffog]

A misfire will send unburned fuel into the exhaust and Cat, and one of the Cats jobs is to burn up the excess fuel before it is expelled in the air. It is made to handle a normal running motor, a misfire basically feeds it more than it was made to handle. Early catalytic cars would occasionally catch fire when a plug would foul.

First thing I would do is install NEW plugs, and maybe add some Techron to a tank of fuel. From there, if you are not mechanically inclined, it is professional mechanic time.

 

[MinnesotaRik]

great tips

Thanks for the tips:

9k miles for me since owning
I did put in new spark plugs

That unburned fuel is making it to the cat even in vapor makes sense with a misfire and why the cat would be hot-- I am surprised it is not even hotter!
I am pretty new to this so had not known what a Cat Code Plug was so I did a little search- Woah! What a can of worms that is!
Mine is red and in place and now I know where the fuses and the relays are.

Thanks.

A browse through fuel delivery in the Haynes manual plus your info leads me to believe it is a clogging fuel injector- I will run the tank if cleaner through and if not better consider represent fuel injectors -- UNLESS anyone out there has any other ideas?
Rik
In MN
1995 GS 1100

 

[happy wanderer]

Not an expert but I think if a bike sits a lot the varnish that builds up in injectors and such is not likely to get cleaned off by pouring stuff in a tank of gas. They need to go to a proper injector cleaning place, get tested and get cleaned with the right equipment and some really nasty solvents. You should use a place that gives you the flow rate data after testing them before and after as well. It is crucial they are the same or as close as possible to the same in a boxer engine.

The backyard check is to pull one injector at a time (be careful with the plastic fuel lines!) and point them in a jar or a coffee can. Crank the engine over and look at the spray pattern of each. There are lots of videos on YouTube and photos on the net of what they should look like. A nice fine even mist is the best I can describe it. If the dribble or are obviously not spraying the same that's a problem.