Funny Idle Sound Question

[stokes776]

I am still getting used to my '98 engine in my '04 bike.

So far I have installed new Exhaust Gaskets and performed my valve adjustments, 3 are .04 and 1 is at .05 clearance.

Even after that, to me the idle sounds kinda funny.

I recorded a video of it and was hoping someone could listen to it and tell me if I need to keep digging/checking or say it sounds fine.

My next steps were going to be cleaning the carbs, contacting another member on this board and see if I can visit them to have them list, and last resort of taking it to a dealership.

This video is after about a 3 mile ride from work to home, so its pretty warmed up already.

http://youtu.be/YVTO7k2Z9y4

Thank you for your time if you listen and comment, I appreciate it!

[adidasguy]

Carb sync?
Sounds like one cylinder is working harder than the other so you get the PUTT putt PUTT putt PUTT putt

Check plugs to see if one side rich or leaner than the other.
Then do a carb sync.

Reminds me of what I've gone through with Junior's engine(s) and the other bikes.

[craigs449]

Sounds fine to me........

[noworries]

She is idling a little low for my taste. You might try inching the idle revs up a title and see how you like that?

[stokes776]

I researched what 'Carb Syncing' is and some of it matches my symptoms.

Other Symptoms: When coming to a stop, the idle will stay high (3k-4k) even once stopped and in 1st with clutch pulled in.  Once stopped I gently let out the clutch just a bit and it causes the idle to drop back down to 1.2 ish.

I have been tweaking the idle up and down and it seems like I cannot find a nice happy setting.  Once I found an idle setting where it was not idling high at stops, it seemed to move as the bike warmed up and was actually too low and it died coming up to a stop at one point, had to keep it feathered until I could stop and re-adjust. Seems like I am always playing with the idle adjust screw and the choke.

But the symptoms of others that have carb synced match up with mine, so maybe this is what I need to do.

Thanks Adidasguy

Now I need to determine if I can build a Manometer or if I should just buy one. Once I have that the procedure seems simple enough given enough time curiosity and persistence.

[stokes776]

Need some help!

Went out and got two guages, same ones that weedahoe got in a different thread for carb synching.

I pulled my carbs off the engine, leaving them kinda hooked up (fuel and electrical) so that I could get at that nipple and attach my guages.  While doing this I noticed the gasket/boot whatever its called on the engine was kinda rusty, so I decided to swap my original ones back on.  While doing this I noticed that on the engine side they were the same, but on the carb side slightly different rubber depth etc, so I am hoping this will help my problems by having the proper (are these what they call the boots?) fit.

So got those on, put the carbs back on with my newly attached hoses off to the side.  For the left carb, I removed the nipple, for the right carb, I removed the hose that went to a T and back to the tank Petcock for Vacuum.

Re-attached the airbox nice and snug. Hooked up my fuel tank sitting on two bar stools off to the left.

Turned on the ignition and tried to start the bike.  It just cranks and cranks but it never turns over. I looked in haynes for any ideas, the only one I found was if the engine is flooded, try cranking with full throttle.

I tried choke full, choke none, full throttle, no throttle, little throttle, waiting 5 minutes, raising the fuel tank higher, setting the petcock to prime, making sure the tank petcock was set to on.

Unfortunately none of these have helped.  My bike is sitting down in the garage with the two guages hooked up to it and the fuel tank on the bar stools next to it.

Any ideas why my bike wont turn over?

I will wait about an hour and if no response, here is what I am thinking:

1. When I semi detached the carbs, maybe by flipping them from side to side, fuel got to where it shouldnt be.  I will remove them and use the drain screws to drain them completely, reattach and try again?

2. I dont understand the vacuum system, remove the guages and put it back to normal configuration, try starting it again.

3. If neither of those work, I think I have fudged up the carbs somehow? Detach them and bring them inside and open them up (have never opened up the carbs before)

Electrical is good, headlights come on, indicators come on.  I checked spark plugs, made sure they were nice and tight, reattached the caps to them about three times each.

[mchollan]

Is the fuel tank on the bar stools higher up than the carbs?  When on pri this is a gravity fed system and the tank will have to be above the carb bowls in order to fill.

To make sure fuel is reaching the carbs, open the carb drain screw on the underside of the carb bowl.  fule should pour out fairly quickly (attach some tubing to the drain in order to not make a mess.

[stokes776]

Huzzah!

I raised the fuel tank up again, made sure it was prime, made sure no hoses were being pinched and it started!

Thank you very much!

I fiddled with it with what the guages show and can only hope I made a difference.

Now, as far as getting everything buttoned back up, I had read that some folks keep the left carb hose in place for future synchs, so they dont have to deal with getting their fingers in there to get that hose attached.

So how does that work? Do I have to clamp off the hose or just leave it dangling?  I wouldnt think leave it dangling because it has vacuum going through it... right?  So what could I use to clamp it?

For the right carb, its accessible enough I can hook it back up how it is supposed to be.

If I need to take the carbs out to put that stupid nipple back on (which I about tore apart, its probably worthless as far as holding a vaccuum) I guess I will, but hoping there is another way.

[mchollan]

Great!  After syncing did your strange idle noise go away?

As for buttoning it back up, I put the rubber nipple back over that port but never put the clamp back on.  The vacuum seems to hold it in place plus its such a PITA to get it off in the first place.

[stokes776]

Ended up going to the auto store and got a small nipple that goes over the hose I have hooked up snuggly, and worm clamped that to itself.

Started the bike up and took it for a spin around the block and it died on me while in motion, was pulling hard against the gear it felt like, and then 0 rpm.  I switched to reserve and was able to get it started again.

I think the dying was due to just being low on fuel.  I was able to ride on reserve with no dying to get fuel.

Now the problems I still seem to have that are unchanged:

Tapatapatapatapa noise.  The funny idle noise is still there.  I wont know for 100% until I put the fairings back on, because they focus the noise back up at me more and make it more pronounced, but with the fairings off right now, if I really listen for it I can hear it.  Usually once I get into higher RPMs it goes away while cruising, but it still sounds funny and the noise is still there once I come back down in RPMS.

High idle. So coming up to a stop the bike will stay 3-4k RPM until I am stopped, and I let out on the clutch, then it goes down to its 1.5, 1.2 area.  This sounds like an easy one to fix, even to me but I have been adjusting this idle screw for about a week constantly.  If I adjust it too high, the bike runs like this, too low and it will die on me at stops.  I cannot seem to find the correct setting, plus its like I need to adjust it one way when the bike is cold and one way when the bike is hot, constantly messing with it, never 100% accurate.

I think I will take the bike for another ride tomorrow to get a fresh take on it without the fuel issues clogging my judgement.  Maybe, just maybe I can adjust that idle screw just right and things will clear up. But I dont see how that will change the tapatapa issue.

Maybe I did not synch the carbs properly, thought I did pretty good, but maybe for this problem I need to take it to a real mechanic, ugh.

Anyone have any other thoughts? Or think maybe I just did not synch the carbs properly?

Oh pictures!  Some of the spark plugs, which to me look the same, the one with wrench in frame is Left cylinder.

Right Spark Plug


Left Spark Plug


Carb Intake Boots (Top: '98 Engine, was old/rusty, Bottom: '04 Engine, Better Condition)
I think the numbers on the boots are even different.  They looked different as if the carbs would fit better into the 04 boots, so I swapped both my 04 boots onto this engine.


Photo of Vacuum Hookup for right Carb


Photo of Vacuum Hookup for Left Carb, Notice the nipple


Carb Synch Hookup

[Suzuki Stevo]

Carb sync?
Sounds like one cylinder is working harder than the other so you get the PUTT putt PUTT putt PUTT putt

Check plugs to see if one side rich or leaner than the other.
Then do a carb sync.

Reminds me of what I've gone through with Junior's engine(s) and the other bikes.

Another trick is to use an Infrared Thermometer on the bend of the exhaust pipe up by the head, the one with the higher temp could be lean or working harder 

http://www.harborfreight.com/infrared-thermometer-93984.html

[Higgins13]

Seems fine, How would changing the exhaust gasket effect anything? lmao

[stokes776]

Seems fine, How would changing the exhaust gasket effect anything? lmao

Those are the intake boots, it seems like the old ones and new ones fit the carbs differently.

I have changed the exhaust gaskets, maybe I did already mention that. I was just thinking if exhaust was escaping with bad seals it could affect performance, so new gaskets should resolve that if it were the problem, but no difference after putting the new gaskets on, this was back when I did the valve clearance.

What sucks is this all started after I checked and adjusted the valve clearances.  I measured whem when I opened it up and I swear they were all around .20- .35 off, whereas if I am not crazy, the proper clearance is .03 to .08.  I got all the valves within that clearance now, but now I am having these problems...

[Higgins13]

It just seems nearly impossible that something such as gaskets could effect it that dramatically unless of course the new ones you have are completely the wrong size...

[stokes776]

I dont think the gaskets (Exhaust or Intake) are causing the current problems.

I swapped out the Exhaust Gaskets because I couldnt remember seeing them when I did the engine swap.  Indeed they were there, but just very black, whereas the new ones were copper/green.

http://www.ebay.com/itm/GS400-GS425-GS450-GS500-DR650-GR650-EXHAUST-GASKETS-/190713193541?hash=item2c67646445&item=190713193541&pt=Motorcycles_Parts_Accessories&vxp=mtr

I changed them out at the same time I made valve adjustments, whereupon the bike started to run funny.

It was just yesterday when I changed the Intake boots, because one was rusty and stuff was flaking off of it, I realized I had my 'old '04' set, and the rusty ones were '98.  Comparing them there is a little difference in how deep the carb can enter into the boot when it mates with it.  Now that being said, I was just kinda hoping it would help and not hurt anything.

After changing the boots, and performing a carb sync the same problems are still there, however maybe I did not perform a good sync, being the first time attempting it.

[Higgins13]

Don't mean to insult you but you said your not sure old ones were there...you Dident double gasket did you?

[stokes776]

No problem Higgins, this is why I am posting, for any and all help!

I swapped engines from my '04 which ran without oil on the highway and damaged something (still not sure what yet, metal in oil, probably bearings) and installed a '98 engine I got from Ebay.

After installing the new one, I was metnally reviewing my work and could not for the life of me recall seeing Exhaust Gaskets when I removed/reinstalled the exhaust.

So seeing how cheap they were and figuring they should be replaced anyway I ordered a set off of Ebay.

When I got the new set in I removed the exhaust and did indeed find the Exhaust Gaskets, I cant remember if they were stuck to the Exhaust or the Engine, but they were there, I pried around with a flat blade screwdriver to make sure there was not a double set, and sure enough there was not.

The old set was black, and my new set was kinda coppery teal ish.

I think I will take off the exhaust and double check again, removing the exhaust is not too difficult.


Update: Rode the bike last night and seemed to do OK, still had the high idle at stops, but I am kind of used to stopping with the high idle and then gently letting out on the clutch until the bike calms down, then I can put the clutch back on all the way and the idle stays where it should.

At the end of my ride last night, sitting in front of my garage all warmed up, the idle was showing 1.7-1.9, so I tweaked it down just a hair.  I will see what the bike feels like the next time I ride it, maybe with the Carb Synch and new Intake boots maybe it will take care of some of the problems assuming I get this idle adjustment just right.

FYI, I have been reading and it seems as though a Carb Synch is always recommended after Valve Adjustment?  I did not know that!

PS. Even though I have the dial vacuum guages, it seems like the liquid manometers are more accurate and easy to build.... What happens if you do end up sucking oil through the carbs though? Any ill effects?

[adidasguy]

What sucks is this all started after I checked and adjusted the valve clearances.  I measured whem when I opened it up and I swear they were all around .20- .35 off, whereas if I am not crazy, the proper clearance is .03 to .08.  I got all the valves within that clearance now, but now I am having these problems...

If they were off as much as you say, something is very weird. I've had feeler gauges leaves stick together. Once I wondered why 0.05 was loose, so was 0.09 but 0.07 was tight --- 0.07 and 0.06 were stuck together.

Now when I check valves, I spread out the leaves. If I am using 0.07, I make sure I can see the ones before and after it so they are not stuck together.


You might recheck the valves.

An extra exhaust gasket will not make things run bad. As long as things are tight, it won't hurt.

If you have newer carbs, you can use new or old intake manifolds. If you have older carbs, you can only use older ones due to the depth of the area the carb fits in to.

Did you replace the o-rings on the intake manifolds? You should if you didn't. Otherwise smear gasket gunk there.

Carb Sync: Carbtune with the steel rods is the best. All work well. Which ever type you use, it is important (read that mandatory) to have a restrictor in the tubes at the carb end otherwise the needles fly all over the place or you suck all the liquid out of the liquid ones.

[stokes776]

I will re-check the Valves then.

This was my very first time checking them.  I had misread the text as .2 to .8, measured the valves and was getting .25 and .3 like I said.  But something was weird, because the feelers I was using did not bend like they did in Kerry's video, the .2 was thick and not flexible.  I re-read the text and forums and found my mistake (needed to be .02 to .08 , I was a factor of ten off).

I then went down to that level of feeler gauges, very thin and flexible, almost felt like I was going to tear the metal when rotating them around until I started to loosen that thumb screw ever so slightly on the gauge to allow them to move easier.

I re-measured and got the same clearances.

Hmm, a restrictor.... yeah I did not have one of those. I just had open tubes straight to the guages.  They fluttered everywhere until I gave it throttle into the 3-4-5 RPM range, and then I could eyeball that they were far or close etc.

I will have to research what that is, how to install one into my tubing.  Just like everything else probably pretty simple, any hints?

[adidasguy]

Here is info on the Carbtune. Same will work for any. http://www.carbtune.co.uk/delivery.html
They give you a piece of tube with a small inside hole you cut and stick into the main hoses.

MotionPro inserts a small brass plug with a  small tiny hole in it.

You could cut the hose 6" from the carbs and insert small watering system 1/4" hose valves. Turn them off. Then turn on just so the fluid starts to move.

The restrictors limit the amount of fluctuation of the vacuum. The long length of hose from the restrictor to the carb device acts as a damper.

I was given a pair of vacuum dials for carb syncing. I saw them use it - needles when all over the place. When I got it I looked in the box and found instructions and the restrictors that never were inserted into the lines.