Tach needle not steady at highwe RPM's

[nico]

Hi All!!
I've been adjusting the clutch on my GS through the side cover access hole. I've read the tutorials and seen the youtube video so I think I am doing it correctly, but when I ride for over 45 minutes at 6 or 7000 RPM's, the tach needle starts swaying....and is I try and accelerate from that rpm, I hear the engine going up in revs, the tach needle does not.  Do I have a toasted clutch?

Something else maybe worth noting: when I'm riding, and I go to squeeze the clutch to shift (say, from 3 to 4th) I barely move the lever and I am able to shift. 

I use oil and the filters from Suzuki and have not yet gone more than 2,000 miles without an oil change.



Also have to mention that I've already put just over 3,000 miles on my GS since I bought it in September of 2013. I've changed the oil and filter twice, threw on an exhaust because the old one was rotting, even went a stint with clubman bars, but now it is back to normal because of shoulder pressure with a backpack. The little GS has done nothing but treated me right!!

[Watcher]

The tac is controlled with a physical cable, if you notice the tac doing funny things compared to the sound of the engine, most likely the cable is bad.  Engine revs up and tac stays in place and a "bouncy" needle both sound like cut and dry cases of bad tac cable.

As far as engine revving up and questioning the clutch, does the engine rev up no problem and the bike speed doesn't increase hardly?  If it'll rev like its racing and the bike won't take off then the clutch is either worn or not in adjustment.  Seeing how you said you can shift by just barely pulling the lever and the fact that you've been playing with the adjustment I'd say its the latter and not the former.  Then again I can shift with no clutch at all...


How many miles on the bike in total?

[Big Rich]

Yeah, is this a mechanical tach or an electric one (E model or F)?

Unless you changed your oil with car oil, I'd definitely be looking at your clutch cable adjustments. 

[robfriedenberger]

What's the year of the bike and what's the milage

[ivany]

If you have a mechanical tach (pre-01?) the swaying happens sometimes. As the lube in the tach thins out it damps the movement of the needle less and hence the needle will sway. The opposite effect is that when it is cold the needle is sluggish to move.

Almost certainly not the clutch - to check that, get into 5th at about 5K RPM and go WOT. If you hear the RPM jump but not much go the clutch is gone, but it's not likely to be this. How much free play on the clutc lever?

[nico]

Hi Guys,
TO answer all of your questions:

The tac is controlled with a physical cable, if you notice the tac doing funny things compared to the sound of the engine, most likely the cable is bad.  Engine revs up and tac stays in place and a "bouncy" needle both sound like cut and dry cases of bad tac cable.

As far as engine revving up and questioning the clutch, does the engine rev up no problem and the bike speed doesn't increase hardly?  If it'll rev like its racing and the bike won't take off then the clutch is either worn or not in adjustment.  Seeing how you said you can shift by just barely pulling the lever and the fact that you've been playing with the adjustment I'd say its the latter and not the former.  Then again I can shift with no clutch at all...

How many miles on the bike in total?

The bike shows a total of 10,600 miles or so. I bought it with 6,700 last September.

The engine revs fine with no restrictions...but when I'm going into a bit of a headwind, at 70mph or more I roll the throttle in 6th and if I roll it too quickly I hear what sound like the engines rpm struggling to get up and the needle on the tach bounces in a similar rhythm as the engine's stuggle/hesitation. It seems like the clutch is slipping, because in a tail wind scenario if I do the same thing, it is fine of barely noticeable.

I think I am adjusting the cable correctly:
-tighten in the adjusting barrel on the lever
-tighten in all the way the adjusting barrel on the case.
-remove the access cover, undo the little brass nut.
-unscrew the small flathead out 2 or 3 turns, then tighten until I just start to feel resistance, back it out 1/4 of a turn.
-use an offset 10mm to tighten the nut while using a screw driver to hold the rod position.
-unscrew the adjusting barrel on the case until there is 1/4" of slop from there the clutch lever itself touches the lever mounting body.
-Go for a quick ride to verify all is OK.

^^That's what I normally do.

I can drop some tri-flo (Teflon lubricant used on bicycles into the tach and (while I'm at it) in the speedo as well.

[nico]

What's the year of the bike and what's the milage

The bike is an '01 with about 10,600 miles on it. It is an E model. no shield/glass/fairing
The guy that had it before me placed a K&N double cone kit, and I installed a Delkevic when the OEM exhaust started to rust heavily this summer.

[nico]

Yeah, is this a mechanical tach or an electric one (E model or F)?

Unless you changed your oil with car oil, I'd definitely be looking at your clutch cable adjustments.

It is a mechanical tach. I honestly did not know that these were also equipped with electronic tachs...must have been the later model years?

I use Suzuki motor oil...10/40, and a Suzuki filter too.

[nico]

If you have a mechanical tach (pre-01?) the swaying happens sometimes. As the lube in the tach thins out it damps the movement of the needle less and hence the needle will sway. The opposite effect is that when it is cold the needle is sluggish to move.

Almost certainly not the clutch - to check that, get into 5th at about 5K RPM and go WOT. If you hear the RPM jump but not much go the clutch is gone, but it's not likely to be this. How much free play on the clutc lever?

Mine is an 01 and it has a mechanical tach. I will drip some lube into the rear of the tach where the cable drive enters....think that would resolve any lack of lubricant in there?

I will do that test, but I am sure it is fine: that is what I do almost everyday when I get onto the highway on my commute. If the clutch is shot should I expect the slipping to happen almost immediately at 5000rpm's? From what I've experiences, it will slip and buck a little bit at about 7,000. I'll do the test and report back.

There is about a 1/4" of slop from where the lever is in its fully retracted position into the lever body and when I start to feel tension. The sweet spot is almost right at the movement range when I start to feel the tension.

Hope all of that does not sound confusing.

[Watcher]

I roll the throttle in 6th and if I roll it too quickly I hear what sound like the engines rpm struggling to get up and the needle on the tach bounces in a similar rhythm as the engine's stuggle/hesitation.

This sounds like the exact opposite as a slipping clutch.

If you yank on the throttle and the engine bogs and struggles trying to move the bike then one thing for certain is the clutch is still holding strong.  In this case the bike is holding back the engine.
If you yank on the throttle and the engine breaks free and revs up without moving the bike, THEN it's a slipping clutch.


Your issue is something else entirely.  Could be the classic carb overflow hose routing issue, if the overflow hose takes in wind it will cause the engine to behave poorly...

[BockinBboy]

That was my initial thought while reading this too, Watcher.  But couldn't pull that conclusion from the original post, but rather some info that's recently filled in and that last description... Especially noting that you have pods.  There is a good thread named 'Crosswind Engine Stumble' about it. 

Gist: The carb overflow should be routed out of ANY wind. 

Longer Explanatory Remarks: Normally, the carb overflow hose is routed over the airbox (around the edge of the air inlet, not across), and terminates between the back of the airbox and the battery.  But when you have an air filter such as the lunchbox or the pods, this routing is changed.  It still needs to go tucked in around the battery somewhere to keep the end of it out of the wind.  Most importantly, out of any wind. Second most important thing is to route it without any kinks or pinches.  If wind catches the end of this tube, the pressure causes fuel starvation issues.  Some folks experience what seems like sluggish throttle response, others experience what's almost like when you need to switch to reserve... sometimes its enough to even stall the bike.  Results differ depending on the amount of airflow that is actually getting to the end of the tube.

- Bboy

[nico]

How do I know where to find this hose?
I'll have to look in my manual later on tonight.

[BockinBboy]

The carb vent tube is the top 'T' connection on the back of the carbs.

- Bboy