bogging off idle?

[Anonymous]

Well here I am in Temple, Texas and I have finally gotten to do a little riding. I seem to have the jetting and settings (on my 83 1100E with Yosh exhaust and 36mm semi flatslides) just about right except for a little bogging/stagger occasionally of idle. It seems to manifest mostly after the bike is throughly warmed up, and i have sat at idle for a few moments. If I blip the thottel once before trying to release the clutch and pull away, he problem does not appear and or clears.
I think it is an idle mixture issue, but I cannot decide if it is too rich or lean, the plugs look good. Anyone with suggestions before I go and screw up my carbs again?

thanks,
Derrick
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[Anonymous]

Anyone with suggestions before I go and screw up my carbs again?

A bog is typical of a rich mixture. If it was lean it wouldn't bog, it would be very crisp and sharp to the throttle, but won't pull well. A bog followed by the engine clearing and pulling hard is a sign of being rich, so try 1/2 turn in on the mixture screws and see what that gets you. Also, you will find a lean pilot setting to cause very abrupt throttle response off idle. That was one of my measures for setting my pilots, I went for a slightly softer response than was probably a perfect mix, just to eliminate sudden surges while rolling on the throttle through low speed corners. At my current settings, it is buttery smooth onto the power off idle and revs as fast as my hand can open the throttle in the lower gears. I found 1/2 turn on the mixture screws to have a noticeable effect to the response and plug readings, but 1/4 turn was not enough of a change.


Mark

[KEITH KRAUSE]

Bogging, stagger, stumble, cough...all can be interpreted the wrong way.
Generally, a bog is a rich mixture, but a stumble off idle, like when leaving from a stop, can be cured by raising the jet needle.
As your bike warms up and the problem worsens, this suggests a rich mixture. So does what sounds like your bike "loading up" at a longer idle.
Easiest, safest thing to try is adjusting the mixture screws. I'm not familiar with those carbs and if they have seperate air/fuel screws or just mixture screws.
Just keep a record of any adjustments, and if you don't like the results, put the screws back and check the basics. Or, check the basics first.
Carbs synched...carbs clean...filter clean, etc.

[Anonymous]

Thanks guys,
I will adjust the mixture screws, and see if I can fid a compromise between good idle and crisp response of idle.
Keith: there are only mixture adjustment screws (these are 36mm semi-flatslides from a 96 Katana, that I bought from Scotty). Now that they are mostly dialed in, they are probably the best thing I have done to my bike,
Now.. whether that is because they are better carbs or because my stock units were so trashed by the previous 23 yrs of use ( and quite a bit of gorrilla fist tuning techniques by previous owners) I cannot say.

Thanks again, and I will post and update.

Derrick

[KEITH KRAUSE]

Yeah. Let us know if this helps. Then we can better help the next guy with the same problem.

[bwringer]

I had an off-idle stumble that was eventually traced to an old foam air filter element that had slowly swollen over the years. Even after cleaning, it was too big for its cage. After cutting a strip off the edge, it fit much better and cured the stumble.

So triple-check your air filter(s), FWIW.