Choke and idle (carb?) questions. Newbie is completely lost!

[bcbickers]

Hiya all!

I know this has been beat to death, but I just go into a fog when reading all of the posts about it.  Please forgive another one.

I just purchased a 93 that has K&N pods, some sort of jet kit (I don't know the jet and needle sizes), and a Cobra F1 slip-on.  The bike runs like a raped ape at WOT and is pretty smooth at part throttle.  However, I have two problems.

First, starting her in the morning is impossible.  I open the choke all the way and start her up (Part choke just kills the engine).  She goes up to about 3500 rpm or so, then "cycles" down to 2000 rpm, then back to 3500-4000 rpm.  This keeps up for about one or two minutes with each low rpm getting lower until the bike cannot recover and dies.  If I try to give her any throttle with the choke open, she floods and dies.  Of course, she won't take a rider until she is warm.

Second, she will not idle at any setting below 1500 rpm.  If I turn the idle adjuster down to get the rpms around 1200, she will run for about 10 seconds then gradually stumble and die.

In case this extra info helps...  The plugs look good (see the pic below).  When I roll of the throttle, the exhaust "pops" a little.  The more rpms, the more pop.  A little like a backfire, but less staccato (sp).

Sorry for the book and asking these silly questions, but I just don't even know where to begin.  I have a Haynes manual on order.  Hopefully, it will be here within a week, but I would like to have a better understanding of how she ticks.  Thanks a million for the help!!  

Brian

Plug pic.  My apologies for the quality.  Looks like it is time to upgrade the camera!

[mp183]

Hard to tell from the pic, but the plug looks on the dark side.  Should be more tan looking.  To me it looks like it's running on the rich side.
If it was running normal or on the lean side you should be able to take off keeping the choke on and just let it warm up on the road.  Hard to say what the remedy will be for all this.  You are probably better off getting a proper jet kit and starting all over again.

[The Buddha]

OK Plug has greylike ashy grey or white... anywhere even a tiny spot... its lean. This plug is lean... jet kits are crap... more specifically they are crap because they dont have 40 pilots in them...fit those in and your issues might disappear. OK If your issue is only at idle, and not at the point you are about to take off from a light ... AKA 0 - 1/8th throttle...then you may be ok with opening the mix screw,that will richen the mix at idleand make it start easier too. As always Check for vacuum leaks, and check float level .... float should be right at the top of the float bowl...right at the gasket mating face, and no more.
Cool.
Srinath.

[Kerry]

Just in case you don't have such a thing yet, check out the Spark Plug Chart from inside the back cover of the Haynes manual.

You might also get some useful info from MXoffroad's How To Read Spark Plugs article or the Spark Plugs page on the drive-you-nuts-with-funky-page-transitions Dan's Motorcycle Repair website.

About the camera: What kind do you have?  Fixed focus (no zoom)?  Low resolution?  My first digital was a FujiFilm 2.1 megapixel fixed-focus job, but it had a close-up mode (of sorts).  Suggestions:

1) Lighting!  Try to light what you're shooting with something OTHER than the on-camera flash.  If you have no other option then no problem.

2) In a situation like the one above, get in as close as you can.  Use the "flower" (macro / close up) mode if you have one.  If the camera will show you whether the image is focused BEFORE you push the button, you could try focusing on a card with large, crisp letters or shapes at the same distance as the spark plug and then take the card away.

3) I think that's it for now.[/list:u]
Good Luck!

[bcbickers]

Just in case you don't have such a thing yet, check out the Spark Plug Chart from inside the back cover of the Haynes manual.

I knew that manual was a good buy!    My plugs look just like the normal plug in that photograph, but the firing tip is more tannish and more pronounced.  Almost identical though.

About the camera: What kind do you have?  Fixed focus (no zoom)?  Low resolution?  My first digital was a FujiFilm 2.1 megapixel fixed-focus job, but it had a close-up mode (of sorts).  Suggestions:

1) Lighting!  Try to light what you're shooting with something OTHER than the on-camera flash.  If you have no other option then no problem.

2) In a situation like the one above, get in as close as you can.  Use the "flower" (macro / close up) mode if you have one.  If the camera will show you whether the image is focused BEFORE you push the button, you could try focusing on a card with large, crisp letters or shapes at the same distance as the spark plug and then take the card away.

3) I think that's it for now.[/list:u]
Good Luck!

Good tips!  I have a four year old Olympus 2.1 megapixel.  It has auto focus and zoom.  The lighting was probably the problem (or was it the operator??!).  I'll try that flower/closeup mode and see if I get better results.  I have always used it as point and click camera.  The pictures it takes of people and places are great!  I always seem to struggle with closeups.   :dunno:

Thanks for the other replies.  Do you really think I need a carb rebuild?  After doing some further reading last night, I am wondering if my float level is too low, and that is why it cycles with the choke on.  If I can find time, I will check it today.  Any other advice is greatly, greatly appreciated!

[Kerry]

I'll try that flower/closeup mode and see if I get better results.  [...] I always seem to struggle with closeups.

Check your manual to see how physically close you can expect to get with the closeup mode.  Try to "fill the frame" with the item of interest.  (More detail in the original makes for crisper resized images.)  If you can't focus when you're super close, back up a bit, zoom in, and steady the camera with a tripod or a stationary surface of some kind.

Do you really think I need a carb rebuild?  [...] I am wondering if my float level is too low, and that is why it cycles with the choke on.  If I can find time, I will check it today.

I assume you're asking about whether you need to rejet?  I'm going to leave that one for those who have actually done it!

As for the float level, you can check it without taking the bike apart using what Srinath calls the U-Tube Method.  If the level is wrong you can follow the Haynes manual (or the bits of it that I have posted in the past) to tweak the little metal tangs inside the carb.

[bcbickers]

Well, I may have found my problem.  The bike kept stalling at anything above 1/4 throttle and 3500 rpms today.  It began leaking gas out of the left carb!!

So, I go home, get my tools, and go back to Mrs. Tempermental.  Off comes the seat and tank.  Hmmm...everything looks ok, but the K&N is soaked with gas!  So, off comes the filter.  The right slide works fine.  Whoops...the left slide is binding badly.  Goes up halfway real easy, then gets "stuck".  Hmmm...off comes the top of the carb.  HOLY MOLY!!!  The carb spring is broken in two pieces!!!!  How in the world does that happen??!

This is as good of an excuse as any to rejet and clean the carbs.  Factory Pro, here I come!  I'll keep ya posted with the results.  I will also work on that camera business and get some pics of the cleaning and rejetting process.