G'day all

Have a check of this and then read on please:-





So I did the valve clearances on my bike last week replaced them with bigger ones and that's all fine, when I went to replace the shims I took the cams out and had to re-time them later.

I did this and turned the motor by hand, there was no binding so I don't believe the valves are fouling or anything, but I could be wrong.

But now the bike has a very rough idle and has this ticking noise in the video. The engine also doesn't seem to be balanced anymore like it used to be, i.e. it's shaking like a Harley.

Any suggestion of things to check?


The other issue when I reassembled it is the throttle seems to hang a bit, this happens when cold or hot, right lock, straight on and left lock.

Might I have screwed up the carb somehow when I removed it for the valves?



Thanks in advance.

Welcome to the site Myles!

I can't watch the video, so keep that in mind..... but from your description it sounds to me like your timing chain might be off by a tooth or so. Pretty easy to check, but you'll need to open up the top of the engine again and find the pic in the service manual to confirm.

The throttle on the other hand.... can't explain that one yet. Have you checked for slack in the cable when it is hanging? You'll want to check it at the carb linkage - not around the headlight or anything.

I would double and triple check your timing.

While you're in there would be a good idea to make sure the cam caps are torqued to spec.  Sounds like something slapping in the top end.

Might want to ensure the chain tensioner is also functioning properly.

Another video for you

Timing all seems in spec to me. any suggestions?

Cam chain tensioner seems to be working fine as well

For the throttle issue: the throttle snaps back like it should and the slack is in spec, the butterflys and plungers in the carb work free as well.

Is it possible you used an incorrect shim?  Valves too tight and slamming shut perhaps?


I can remember when I refit the valves, got new springs, and shimmed them up in my first GS they did get louder but it wasn't anything like yours.
Not quite sure where to go if everything is in spec.

Shims that I removed were between 0.07mm and 0.1mm clearence, so i put in +0.05mm and the clearance now seems perfect at 0.04mm right in spec.


I checked the end play of the cams as well, and the retainer springs are in place and working fine.

Couldn't tell from the second video, but is the R-T mark on the signal generator lined up with the center of the left pick-up coil?
Did you get the cams in proper order, i.e. the EX cam at the exhaust end of the head and the IN at the intake end?  Seems obvious, but thought I'd ask.

The arrow at the 2 mark is where you start your pin count.  The arrow at the 3 mark is where you should reach 18 pins.  Anything other than this should be considered "off time".

Quote from: Arpee on January 30, 2017, 07:38:33 PM
Did you get the cams in proper order, i.e. the EX cam at the exhaust end of the head and the IN at the intake end?  Seems obvious, but thought I'd ask.

They appear to be in order from the video.
The IN side doesn't have a 1 or 2.  It makes that kind of hard to fudge when you get to the timing step.

Hmm...

From the image gsJack posted and the second video it appears you are not set at TDC.
The mark isn't the dot between the R and T, it's the line just clockwise of it.
This could put you off a tooth up at the cams.

GsJack, you may be a god walking among men. Why is this information nowhere to be found online ffs  .

I retimed it today at the dot between the R and T and it runs and it can be ridden but seem like ignition might be off. Hopefully Tomorrow ill retime it to the now revealed TDC mark and everything will be gravy.

My thinking is with the ignition timing being off this may be causing the throttle issue. the below video shows the issue as it was today, will post again tomorrow after I've retimed it the third and hopefully final time.

Quote from: mylescooper on January 31, 2017, 05:00:58 AM
GsJack, you may be a god walking among men. Why is this information nowhere to be found online ffs  .

I could swear this was available on the GSTwin parent site, but at any rate googling "gs500 timing" can lead you to a PDF of the service manual, within is all kinds of helpful info including the timing diagram.

So yup I didn't do the timing right the first or second time. The bike runs tops now.

Still a clicking when warm but it's livable. Throttle seems to have fixed as well.

Thanks for the help everyone

Glad you got this sorted. Get yourself a copy of the Hanes or Clymer manual. They both have a diagram like GS Jack posted. The $30 you spend on the book will save you from stuff like this in the future.

The GS500 engine always ticks a little bit when it is idling warm, so you may just be hearing normal engine noises now.

 

Luckily being a tooth off won't cause any internal damage.


Does anyone else feel like the idle was slow to return after those throttle blips?

Could just be because the idle was set to ~1800.
Once you get the idle set with it nice and warmed up let me know if anything changes.

I'm very thankful of that Watcher.



Check that and let know what you think about the throttle and ticking.

It's always hard to tell from cell-phone videos, but to me it sounds like the valves are being valves.  Especially after adjusting the clearances you might have tighter valves and that's just the sound of them slamming shut.
Doesn't sound overly noisy to me, and it may quiet down over time.


Your idle should be set around 1200-1300 rpm with the choke off and the bike nice and warm.  This is adjusted with the big brass (or sometimes white) knob between the carbs.


Re: the 2.5-3k rpm thing.  Was that the engine naturally climbing like that or were you actually on the throttle to get the RPM up?

If it likes to climb by itself like that you could have a choke or throttle cable that's slightly out of adjustment.  Could also be an intermittent vacuum leak somewhere.
Next time it floats up on it's own mist the carb area with a spray bottle of water.  If the revs drop immediately you're sucking in air somewhere you aren't supposed to.

Glad to see your timing issue solved. Also, it is not necessary to remove the cams to get the shims out. There is a tool available for depressing the bucket and then the shim can be prised up with a small screwdriver and lifted out with a magnet. THE howto and the wiki pages will have all this info.

Don't get too hung up on the ticking noise, sounds normal to me. I recall someone on this forum describing the sound of a well set up GS to a sewing machine. Also, a fence or wall or another vehicle at lights can reflect back noises as well.

honestly with the GS.. if you're sure everything is in spec.. just let it be noisy, the engine is one noisy SOB to begin with... and when I changed my valves my engine got noisier then I remember too.

Sounds pretty near about every other, including my GS that i've ever heard run,  especially before it's nice and warm.  Agree with Watcher, sounds like valves being valves.