K11 Owners Group

red · Posted: Tue Apr 15, 2008 3:00 pm Post subject: Backfire and Lack of Acceleration

My bike has developed a couple of issues that may or may not be related to one another.

Backfires. On occasion when I blip the throttle to down shift, it back fires. It usually only does it one time. And is not consistent.

The other issue is a lack of power to accelerate, bogging. This only happened a few times over a two week period and has not come back. I was cruising at 150 kph, decided to pick it up a bit. When I twisted the grip it was like the bike was bogging. When I let off and held the speed constant it ran fine. I waited a few minutes (5??) then accelerated and it worked fine. It did this to me off and on at various speeds for about 45 minutes. It has not done this since.

The issue with the backfiring was taking place prior to the bogging. It backfires on occasion to this day.

I am looking for suggestions: O2 sensor, Throttle Position Sensor, Fuel Pump, ???

I have replaced the fuel filter and plugs so far.

Cheers, Ken

rydor · Posted: Tue Apr 15, 2008 3:05 pm Post subject:

PLug wires and valve adjustment?

Jim · Posted: Tue Apr 15, 2008 3:42 pm Post subject: backfiring

Ken - it helps if you have the year and model in your signature.

I would say - without knowing anything about the bike - throttle position sensor.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Euripides · Posted: Tue Apr 15, 2008 4:10 pm Post subject:

Red: Your problem could be a simple vacuum leak. Check all the vacuum lines and connections. - Euripides

red · Posted: Tue Apr 15, 2008 5:28 pm Post subject:

The bike is a 96 K11RS

How/where do I go about checking the vacuum lines? Where are they, etc? Is there a diagram you can point me to? I do have the Clymer manual, if a suggestions from that book will assist.
_________________
2008 GS Adv
1983 Honda CB1100F, Aussie Model, Red/White
1983 Honda CBX550F, Red/White

Euripides · Posted: Tue Apr 15, 2008 5:39 pm Post subject:

Red: Look in your Clymer manual under "Fuel injection system, Emission Controls, etc. You will see a diagram of the fuel injection system. There are two vacuum lines. One connects to the Fuel Pressure Regulator. Another connects from the crankcase to a part of the air intake system and is a known source of leaks. Study the Clymers manual for your engine. - Euripides.

Off the grid · Posted: Tue Apr 15, 2008 5:51 pm Post subject:

Simple things first.

Check plugs and wires carefully.

Bottle of Techron in the tank.

Replace TPSensor.

Wouldn't suspect fuel filter because you would be crappy at all RPMs.
_________________
Bane of your existence since July 2006
2007 Triumph Tiger ABS. "Sabertooth"
2009 Husqvarna TE610. "The dirty Italian mistress"

Jim · Posted: Tue Apr 15, 2008 6:22 pm Post subject: Techron

Ken - I would recommend only half a bottle of Techron - that bottle is made for a much larger tank. But, to the best of my knowledge, it's not available in Canada. Crying or Very sad

When I had backfiring problems with my other K, adjusting the TPS took care of it.

Sorry, I can't keep track of who is where. Is this the bike that's been to Anderwerks? If it hasn't been there - take it! Dave will get it sorted out for you and running like a top - he's one of the best in all of Canada.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

red · Posted: Fri Apr 18, 2008 10:44 am Post subject:

I will be doing some work on the bike over the next week. I expect with all of this input I will be busy.

Thanks for the suggestions Guys! I will let you know how it turned out after a future test ride.
_________________
2008 GS Adv
1983 Honda CB1100F, Aussie Model, Red/White
1983 Honda CBX550F, Red/White

lrome48 · Posted: Fri Apr 18, 2008 12:56 pm Post subject:

Red,

I had the same trouble. The TPS connector was contaminated with condensation. I just took off the connector, blew it out with compressed air, and checked the condition of the contacts. I think I had to slightly tweak the contacts so they would have more insertion force, then I cleaned the TPS side of the connector as well, coated the harness side with dielectric grease and reinserted it. Not a single hiccup in over 20K miles. The connector tends to loosen over time and the insertion force diminishes. The way my bike stumbled and bucked and spat and backfired, I thought I would have to replace the TPS for sure, but so far...no worries.

Just my 2 bits.

Cheers,
_________________
Larry
K75
97 K1100 LT Specialk under construction
87 SpecialK75 Carols done!
2004 K12 Special the 'Beast' delivered
K1100 Standard Custom Gone but not forgotten