timing

[mchollan]

I had to replace 2 valves on a 2004 gs500 I bought.  I replaced the valves and set the shim clearances with some new shims I got from cycle recylce for $5 a piece (thanks to someone here but I can't find the post anymore).

I set the timing and buttoned it all back up but now the bike idles at 5000 rpm. 
I had already cleaned the carb, set the floats, checked the fuel/air mixture screws etc. so I don't think its the carb.

My question is, if I was off on the timing could this cause the high idle issue? 

Also, I checked the compression too and it matches what my book says is good compression.

[adidasguy]

Throttle cable tension?
Did the choke cable get connected correctly?
Idle adjustment screw?

[mchollan]

Throttle cable snapps back to position quickly. 
Choke cable is attached correctly (as far as I know).  The bike won't start without it, but after starting if i turn the choke off it bings the rpms down slightly (maybe to 4500).
Idle adjustment screw is backed out all the way (so it barely touches the throttle spring).
I've also checked the boots around the carb.  They don't look cracked and they fit tightly around the carb.

[adidasguy]

Throttle snapping back: doesn't mean there is enough free play. should require about 1/4" of rotation to make the throttle move. You should be able to wiggle the throttle a little and nothing happens. More free play is better than none.
You have 2 throttle cables: a pusher and a puller. both need proper adjusting.

Look at the slider bar for the choke. Does it move all the way left and right when you move the choke lever?
It is very easy to get the choke cable attached wrong at the carbs. You've got the cable end, the spring and the metal end of the cable goes in that slot all the way. I always have to triple check that thing.

[mchollan]

You nailed it!  I wanted to prove it wasn't the throttle cables so I took them off. I left the choke on.  Started it up.  Now with the choke on it idles at about 2k and after warming up a bit I take the choke off and it dies down to about 1100 but has trouble not stalling.  I'm sure with a bit of idle screw adjustment I can get it right.

Thanks, I owe you a beer.

[mchollan]

So I fixed throttle cable issue but I am still having trouble with keeping the bike at idle speed.  It starts right up as long as the choke is on, but as soon as I turn off the choke it stalls.  If I turn down the choke about half way it will sort of idle but it makes a strange clicking sound and the revs die way down and it picks back up again.  I shot a video.

http://www.youtube.com/watch?v=Soyz712wARU&feature=youtu.be

Since I can keep it going and even open the throttle up pretty high (in the video I hit about 7k before letting go) I don't think its a fuel supply issue.   I also checked the float height before I took the video:


Here is a picture of the sparkplug after i took the video:


Any help or suggestions would be greatly appreciated.

[mchollan]

Listening to that noise makes me think its the cam chain tensioner.  It sort of sounds like the chain is going slack then getting taught again.  When I put it back in after replacing my valves, I did think to myself that the spring on it didn't feel as powerfull as it did when I took it off.

Any comments/suggestions?  I'm pretty sure this in a non-interference engine, so I wouldn't expect the valves/piston heads to get mangled if it slipped timing. And i would expect as long as I kept the rpms up, the chain would stay more taught then running the lower rpms (at idle). 

Anyway I am going to call my local used bike parts shop and see if they can get me a good deal on one tomorrow.  Otherwise , anyone have a spare they could part with for a few bucks?

[Funderb]

my bike ran like total shaZam! when the timing was one tooth retarded on the cams. When you set timing, before you put in the tensioner, the cams SEEM a little too far advanced, but they roll back when the tensioner pushes the aft part of the chain into proper tension. Check your timing just in case.

then check/clean/replace plugs

and make sure your boots are tight and crack free.


and what front end do you have on that thing? f1?

[Paulcet]

I'm pretty sure this in a non-interference engine, so I wouldn't expect the valves/piston heads to get mangled if it slipped timing.

That would be incorrect. However, one tooth off will not crash a valve.

[mchollan]

I'm pretty sure this in a non-interference engine, so I wouldn't expect the valves/piston heads to get mangled if it slipped timing.

That would be incorrect. However, one tooth off will not crash a valve.

Good to know.  I have seen some contradicting statements on here.  Just for my knoledge, is it possible for the intake and exhaust valves to collide, or just for the valves to hit the piston head?

my bike ran like total shaZam! when the timing was one tooth retarded on the cams. When you set timing, before you put in the tensioner, the cams SEEM a little too far advanced, but they roll back when the tensioner pushes the aft part of the chain into proper tension. Check your timing just in case.

then check/clean/replace plugs

and make sure your boots are tight and crack free.


and what front end do you have on that thing? f1?

By front end, you mean the forks up to the tripple right?  I'm not sure what I have on there.  The original owner seemed baffled when I asked him how he got the clip-ons on there.  If I snapped a few more pictures could you help me figure out which front end it is?  To be completely honest I wouldn't mind going back to the stock front end with the raised handle bars.  These clip-ons interfere with the gas tank and car really pinch your hands.

[Funderb]

well, if/when you do, let me know what you find out. i'll take those clips off your hands if you want. might work better with the pre-01 tank 

[mchollan]

I just wish I knew what I had on there so I would know what to replace.  I have the upper tripple off a stock gs500 but they won't bold on becuase the lower tripples are from some other bike.  It makes the gauges look kind of funny too because they had to be pushed back in order to make room for the front brake resivoir.

The previous owner did NOT do a good job.

Anyway I ordered a new timing chain tensioner off ebay for $9.  Should be here in a few days.  I'll strip the bike back down and check the timing while I install this.  This time I'll take some pictures.  Maybe you guys can confirm I have the timing right.

Thanks.

[burning1]

Good to know.  I have seen some contradicting statements on here.  Just for my knoledge, is it possible for the intake and exhaust valves to collide, or just for the valves to hit the piston head?

It's a hemi engine. If your valve timing is *way* off, the valves could hit. OTOH, the aftermarket cams add a lot of lift and duration with no problems. You'd have to really screw up the timing to make the valves collide with each other.

[mchollan]

I'm really hoping these are the stock cams...although there have been quite a few mods done to the bike before I got it.  I'll post pictures after I have torn the thing apart again.

[mchollan]

Alright, I pulled the bike apart....again.  This time I took some photos.  This is how my timing is currently set.  Can anyone confirm/deny this is correct?

Intake/Exhaust timing:

Red circle indicate each link 1 -18. Yellow circles are the timing markings 2 on the exhaust cam and 3 on the intake cam.  Green arrows indicate the direction of the indent on the cam ends.


Yellow circle indicates the timing mark 1.


Crank Position:

[Funderb]

looks perfect.
Which sucks for you.


I suggest your next steps: Check coils to see if they are in spec (Resistance with multimeter).
+wire to -wire = 3-6 ohms
+wire to plug cap = 18-30 kohms

if that comes out okay, replace your plugs, you never know. i bought a pair that had one fail after only a couple months.

after that, you need to go chasing vacuum leaks and that sort of thing.

[mchollan]

Coils seem to be in spec.

Left side Primary: 5.5 Ohms
Left side Secondary: 30 KOhms

Right side primary 5.7 Ohms
Right side secondary 31 KOhms.

I know the right side is just out of spec @ 31 K, but would that really cause such bad performance.
I have a second set of plugs.  I'll put them in when I get the thing put back together.

Onto my troubleshooting, Is there a way to make sure that the throttle position sensor on the right side of the carb is working properly?

Thanks again for everyones input!

[mchollan]

I put my new cam chain tensioner in.  I still have the same behavior.  When the bike is unwilling to idle without choke, that is a sign of being lean correct?  The next step I should take is to check for vacuum leaks?

[RossLH]

The next step I should take is to check for vacuum leaks?

You'd think that step would come before changing the cam tensioner...

[mchollan]

Ha.  Well its a little late for that.  I changed it while I had the whole thing apart to double check the timing, which i posted the pictures of a few posts up.  It looked correct but I remembered the chain tensioner being...less springy when I put it back on. So I bought a new one for $9.

Now I still have the bad idling issue.