Reasons for poor gas mileage?

[Easy Rider]

Originally Posted by alanmcorcoran

1) Service manager called me back and claimed they DID do valve adjustments but "didn't charge me for it."
2) He did say I should not be riding it with the choke on at all as that can lead to fouled plugs - and some of the symptoms I am having.

So it won't RUN without the effing choke; what the hell are you supposed to do ??

1) B.S. The charge for that alone is usually around $100. I'm sure they routinely give away hundred dollar bills.

2) Total bullshit. When you foul the plug on a single cylinder bike.......it stops running. Is he also telling you that they did NOT check the plug when they had it.......or that it fouled again before you made it off their lot ???

Is there another Suzuki dealer within reasonable distance from you?
This one sounds totally incompetent.

[alanmcorcoran]

Easy,

This is why I don't like things that need to be serviced. You can imagine the thoughts that occur to me when they follow up this sort of advice with, "and if it's still not working right, bring it back in and we'll take another look at it..."

[mr. softie]

Alan, a spark plug that is beginning to foul will provide less than optimal performance, leading to hesitation, rough/low idle, decreased fuel economy etc. This is more immediately apparent on a single cylinder engine than on a multi perhaps. If you are adding enrichment through use of the "choke" in order to compensate for these symptoms you may be fouling the plug worse, and eventually the engine will stop running altogether. If the plug is not badly fouled it may clear up by riding at speed for a while. The plug is easy to check and would be the first thing I'd check given your bikes symptoms. Spark plugs can break down for not so obvious reasons like improper gap, a crack in the insulator, etc and that's why I suggested just throwing a new plug in it as a fist step.

Of course if the plug is looking good I would check to see you are getting a healthy spark, and that your intake connections are unrestricted and tight. Make sure the stopper plug is still in the end of the tube coming out the bottom of the airbox, and that clamps etc are tight, as any leak at all could be causing the bike to run lean (crappy idle etc.) and needing a richer mixture to compensate.

Keep us posted and let us know if you resolve the problem k?

[alanmcorcoran]

I appreciate all the info. Whether I act on any of it is a different story. My usual approach to problems that I don't feel qualified to solve is first to ignore them and hope they go away. (Sometimes this actually works!) When that doesn't work, I either suck it up and make a run at fixing it myself, make another effort at locating competent professional help, or buy a new one of whatever. For some things (notebook computers) I usually skip straight to step 3.

I'm going to give the Seafoam a chance to work (Since I got the Strat I'm putting a lot less miles on the GZ and I'm still only a half tank through seafoam tank #1) and continue to experiment with the choke, idle and warm-up. In all likelihood, I'll take it to a shop to have them check the sparkplug. I think the odds of me screwing it up further or not really competently fixing anything that's gone awry are pretty high. If they do find something wrong with it, I'll consider effing with it myself should the scenario repeat itself.

[patrick_777]

Originally Posted by alanmcorcoran

I think the odds of me screwing it up further or not really competently fixing anything that's gone awry are pretty high.

It's very unlikely.

[mr. softie]

Alan, I had typed all this before I saw your last post so I'm postiing it anyway. If you can change a light bulb you can change a spark plug!

A spark plug that is beginning to foul will provide less than optimal performance, leading to hesitation, rough/low idle, decreased fuel economy etc. This is more immediately apparent on a single cylinder engine than on a multi perhaps. If you are adding enrichment through use of the "choke" in order to compensate for these symptoms you may be fouling the plug worse, and eventually the engine will stop running altogether. If the plug is not badly fouled it may clear up by riding at speed for a while. The plug is easy to check and would be the first thing I'd check given your bikes symptoms. Spark plugs can break down for not so obvious reasons like improper gap, a crack in the insulator, etc and that's why I suggested just throwing a new plug in it as a fist step.

Of course if the plug is looking good I would check to see you are getting a healthy spark, and that your intake connections are unrestricted and tight. Make sure the stopper plug is still in the end of the tube coming out the bottom of the airbox, and that clamps etc are tight, as any leak at all could be causing the bike to run lean (crappy idle etc.) and needing a richer mixture to compensate.

Keep us posted and let us know if you resolve the problem k?

[Easy Rider]

Originally Posted by mr. softie

Of course if the plug is looking good I would check to see you are getting a healthy spark, and that your intake connections are unrestricted and tight. Make sure the stopper plug is still in the end of the tube coming out the bottom of the airbox, and that clamps etc are tight, as any leak at all could be causing the bike to run lean (crappy idle etc.) and needing a richer mixture to compensate.

Spark doesn't usually get better as the engine warms up but..........
The rest of that is an excellent suggestion that I have been meaning to mention but the tired old brain somehow lost track of.......
Given the symptoms, any shop with even marginal competence should have checked all that while they had it, hence the suggestion to find another shop.
Master Mechanic Alan should be able to check the plug on the tube himself; the other stuff.......maybe not. :biggrin:

[alanmcorcoran]

Guys, I seriously appreciate all your insight. Some confounding things:

1) My problem is strictly pre "full warmup." The bike idles and runs quite nicely after about 15 minutes of 40 mph stop and go. Does the warmup affect the foul plug?
2) The bike only stalls when I'm not moving - Typically slowing to a stop and pulling in the clutch.
3) If the bike does stall - sometimes it is hard to re-start. But it's usually not hard to start absolutely cold with the choke full on.
4) The main thing that bugs me is the idle is all over the map, from racing (2K rpms or more) to stalling. ANd this can happen without touching anything. That's why i thought there might be a thermostat.

Anyway, for right now, I have dropped the idle back down to a reasonable level when it's hot. (Not quite Putt-putt, but a little higher and smoother.) This puts me back in jeopardy when it's not hot. I am going to try letting it warm up with the choke on for a few minutes and then take off with the choke completely off and take my chances. If I think its about to quit, I'll goose it a bit with the throttle. I'll keep this up until I've done two tanks of gas with the seafoam. Then maybe I'll look at the plug. Then I will probably take it into a dealer again, leave it overnight, and make the service manager ride it in the morning. The Strat is getting its 600 mile service (already have over 750 on that one) so maybe I'll take Suzy out for a longish ride and see if that doesn't kick something loose. I'm sure it is psychological, but the power feels down, and I feel like I have to blow something through the carb jet.

The bike runs pretty nice just before I get to work (or home.)

[mr. softie]

Originally Posted by alanmcorcoran

1) My problem is strictly pre "full warmup." The bike idles and runs quite nicely after about 15 minutes of 40 mph stop and go. Does the warmup affect the foul plug?
2) The bike only stalls when I'm not moving - Typically slowing to a stop and pulling in the clutch.
3) If the bike does stall - sometimes it is hard to re-start. But it's usually not hard to start absolutely cold with the choke full on.
4) The main thing that bugs me is the idle is all over the map, from racing (2K rpms or more) to stalling. ANd this can happen without touching anything. That's why i thought there might be a thermostat.

The bike runs pretty nice just before I get to work (or home.)

That is a conundrum Alan! Sounds like you have a plan. BTW hows your German? Here is a nice slide show of how a carb works for your amazement: (A picture is worth a thousand words, German or not) Weiter is German for next!
http://www.motorrad.de/v2.0/technikt.../vergaser.html

[alanmcorcoran]

Der photosliden machsensen von der stallenfarten und spitzensparkenhardenstarten.

As you can see, my German is crap. Thanks anyway.