Ignition issue

[smokestack]

Thanks. I suspect it's running very hot (or was running hot for lack of oil) and it burnt out. A little nervous to stick a new one in until I can figure out why it's running so lean/hot. We'll see if the valve clearances are in spec.

[Bluesmudge]

I wouldn't worry about re-damaging the replacement too much. The ignition pickup seems to be a fairly common electrical failure on these bikes. I replaced mine at 22,000 and I'm now at 37,000 miles and have never given it a second thought. If I recall, they are also not too expensive to pick up second hand.

[smokestack]

That's reassuring... it was running about a quart low for a few hours and guessing the extra heat might have damaged it too. Was lucky to find one on ebay for $50.

[jeZZa]

" I try restarting and the starter motor sounds fine but it won't turn over."
to me that sounds like the startor clutch is slipping, does the engine crank normaly or do you just hear the startor motor spinning?

[Jimbob]

Smokestack is this the part you replaced?

http://www.ebay.com/itm/2005-Suzuki-GS500F-GS-500-F-04-09-Engine-Motor-Signal-Generator-OEM-Original-/391224858592?hash=item5b16d197e0:g:YZ8AAOSwHnFVzNP2&vxp=mtr

[smokestack]

Yeah, that's the one that tested bad last time it stalled. I won't have the part until tomorrow but I'll report back once it's installed

[smokestack]

" I try restarting and the starter motor sounds fine but it won't turn over."
to me that sounds like the startor clutch is slipping, does the engine crank normaly or do you just hear the startor motor spinning?

I think I misused "turn over", I meant to say that it cranks but won't start. Starter motor sounds fine.

[smokestack]

The signal generator coil fixed it.

The bike is still running very hot, practically cleaned off the spark plugs in 30 miles.

It's also developed this ticking sound that's consistent with engine RPM. It's inaudible when cold and gets louder as it heats up. Just put in non-synthetic 10W-40. The valve clearances are in spec with the exception of the left exhaust valve which is a bit less than .03mm (the lower bound). The cam chain was looser in places than others. The tightest lengths had almost no play, and the looser ones maybe 15mm but I didn't measure.

It also starts idling high, around 3.5k, after it warms up.

If this is all a function of heat I'll just rejet.

[smokestack]

Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?

The stock jet sizes are on right now (17.5/60/130), stock exhaust and OEM filter in the airbox. My scientific wild-ass guess is to go to 20/65/140 and hope it cools down. The plugs look almost brand new after running it for 30 miles.

[Suzuki Stevo]

Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?

The stock jet sizes are on right now (17.5/60/130), stock exhaust and OEM filter in the airbox. My scientific wild-ass guess is to go to 20/65/140 and hope it cools down. The plugs look almost brand new after running it for 30 miles.

I went 20/60/132.5 with a shock bike, I think your good but the 140 is probably a bit Fat for a stock bike 

[Big Rich]

Carb question: do the jets actually turn on and off depending on throttle position? Pilot 0-1/4, mid-main 1/4-3/4, main 3/4-full -- is only one of those providing fuel at a time?

No, each circuit overlaps each other. It sounds silly, but true. Now, if you take out your main jets altogether it will still idle, but not the way it should. Have a look at these first couple charts for an idea:

https://www.google.com/search?q=carb+jetting+chart&hl=en-US&source=univ&prmd=isvn&tbm=isch&tbo=u&fir=qI5QQmUYVCzI-M%253A%252CG1Xg3ZjarfjPqM%252C_%253B8B4W6IrIb4ECvM%253A%252Ck8KG-spHl4lJ9M%252C_%253BwkaQKTuusOHYIM%253A%252CzOiN5F3S9STo-M%252C_%253BqJbvwhCLo4j1VM%253A%252CAU3kjvUtdqZnSM%252C_%253BYj3GiNRvuezINM%253A%252CJIIuIzU6383hVM%252C_%253BYZXkHmqfKq_EuM%253A%252CIKWN8Q3NlfM0aM%252C_%253BPdE8yNqK86cpNM%253A%252C4_CcGwWHohHZfM%252C_%253BgdLbIJ5ZP4z6JM%253A%252CrKpTn0MBbSfQEM%252C_%253B8PLpIHoFtCPW9M%253A%252CrKpTn0MBbSfQEM%252C_%253BV_XZmb7EO_IKWM%253A%252CIqJ8Phy3wUKCaM%252C_&usg=__-cfjqkdHEwfkZs7F4l0oiji0WPM%3D&sa=X&ved=0ahUKEwjJw6rZzP_MAhVHTFIKHbclBXYQ7AkIIg&biw=360&bih=615&dpr=4

[smokestack]

I went 20/60/132.5 with a shock bike, I think your good but the 140 is probably a bit Fat for a stock bike 

Yeah, I was thinking better to err on the side of too rich and throw on a different filter if it's too much.

No, each circuit overlaps each other. It sounds silly, but true.

Got it, thanks.

I'm looking on Jetsrus.com and they only seem to sell mains and pilots, but not mid-mains? The wiki says that the mains and mid-mains are the same part number but they're definitely different sizes on my carbs. Do the physical dimensions scale down with the jet size?

[smokestack]

Sorry, this is the jetsrus.com page I was referring to: http://jetsrus.com/a_jet_kit_street/suzuki_500_GS500F.htm

[jdoorn14]

If you pull the carbs and look at the jets, you'll see the factory 60 & 130 jets look the same on the outside, but the inside diameter is different.

Might be overly simplified, but that's how they appear to my eyes.

[smokestack]

Yeah, all three appear to be different sizes to me too. I can't find anyone on the web (Z1, BikeBandit, Jetsrus) that sells a "mid-main", or anything other than a main and a pilot.

[jdoorn14]

Part 27 (Jet, Main 60), and part 16 (Jet, Main 130) both have the word "main" in the Suzuki parts fiche. I assume this is because they are both technically Main jets of different internal aperture sizes. (I'm not a carb expert by any means.)  Part 26 is the 17.5 pilot jet listed on the fiche. Again, specifically listed as "pilot" jet. Given the overall function of each jet, it seems appropriate for the mid-main to just be a small internal aperture main jet.

[smokestack]

My naivete is causing a lot of problems. The main jet was screwed into a much larger jet-looking thing that fits over the needle (the needle jet?) and looked like a single piece. Managed to separate the two with a small spacer and flat head. It is the same size as the mid-main. Back in business for now.

Sorry for the confusion... thanks for the help jdoorn

[Janx101]

Buddha is a good jets info source also!

[smokestack]

You mean the enlightened one? I hope he's listening..

[jdoorn14]

I'm sure Buddha is listening. Holiday weekend and all usually means people get a bit scarce for a couple days.

BTW, the only place I've ever found any reference to a "mid-main" relative to the GS500 is here in this forum. It's likely spawned from the difference between the 2 circuit and 3 circuit carbs as a way to explain the functions. I was confused myself until I pulled the carbs to clean the bowls/jets on my '07 and referenced the parts fiche a few times just to know what I was looking at.

Also, the parts fiche isn't always to scale. They're more concerned with relative location and assembly than scale. The 60 & 130 are basically the same size in your hand, but the parts fiche shows one of them (I think the 60) to be a lot smaller than the other.