Topic: What order do you check timing carb sync and idle adjustment...

[juntjoo]

... so you're not stepping on your own feet? Bike was running fine except for some 'clack'ing so I just went in to check the valves and low and behold had to redo them. This time to 10lbs torque per Clymer so nothing gets loose, but now it runs horribly making spitting noises and #1 exhaust is not hot so I re-did idle adjustments per book(quite intricate) and still crappy. Mind you just 24hrs ago I was losing cops with this thing, just had a clacking to it. No vacuum leaks. I'll check #1 valve clearances again since it's the cool pipe. Already checked for spark, cleaned spark plug tips. So IDK. I expect to find #1 clearances fine as I did each one super extra slow while holding my breath. What's your first impression?

[Paintedseat]

Valves, timing, sync, idle

[jgger]

Carbs are ALWAYS the last thing you fiddle with.

[Paintedseat]

I cool pipe is most likely a carb out of sync.

[juntjoo]

So would timing cause just #1 not to fire? I swapped it's spark plug with another, bike is leaning left on kickstand.

I tried turning out the idle screw like 3 whole turns just to see if it was a matter of lack of fuel. I messed with timing b4 basically it was fine smack dab in the middle as originally and still is so I'm guessing it's not timing.

Do I test again from cold and Rev high til all get hot to check #1?

[juntjoo]

 

I cool pipe is most likely a carb out of sync.

Lemme check that...

[crazypj]

You didn't set tappets at overlap instead of TDCC?
Clymer is generally only good for propping up an uneven table leg (IMHO) 

[juntjoo]

You didn't set tappets at overlap instead of TDCC?
Clymer is generally only good for propping up an uneven table leg (IMHO) 

My knowledge of how it needs done off the lobes plus this time I finally followed book to a T, + correct torque to ensure no loosening nuts, I'm sure I got it right this time

[Paintedseat]

Turning the air screws out 3 turns is going past their adjustments. At a certain point there is no more effect.

[juntjoo]

I was just ruling out it being turned in too much.

So my #1 sync was off but now after adjusting it I can't get it below 1.8krpms.

If I turn idle screws in all the way I can bring down to 1.5krpms.

1st cylinder still not hot. When I create a leak by pulling the sync gauge tubes out individually, all but #1 cause rpms to drop.

Accelerator cable not stuck, allows arm to fully retract.

Choke isn't doing anything wrong.
 
The valves are done, in fact the old clacking is gone. I totally forgot. I was so excited for losing the clacking but then immediately got this issue.

Carbs are synced good.

Main idle/sync knob on #2 I adjusted back from too much in.

Why suddenly is it revving so high? Happened AFTER i CORRECTED the #1 off-sync, as if my bike had been adjusted to a bad setting somewhere. Hmm...

[Paintedseat]

You have to adjust all carbs off of #2. Where are you getting your carb adjustment numbers? It's not about a certain vacuum it's about them all pulling the same. Just because the accelerator pump is moving doesn't mean it is pushing fuel to all carbs. 1 is the carb with the most problems with blockage from pump. Have you verified you are getting a stream of fuel to all carbs?

[juntjoo]

You have to adjust all carbs off of #2. Where are you getting your carb adjustment numbers? It's not about a certain vacuum it's about them all pulling the same. Just because the accelerator pump is moving doesn't mean it is pushing fuel to all carbs. 1 is the carb with the most problems with blockage from pump. Have you verified you are getting a stream of fuel to all carbs?

Carb adjustment numbers? I just adjust off of #2 as you seem aware of. No numbers, just screws to adjust to make gages all read like #2

I don't think I said anything about the accelerator pump. I checked that to be fine a month ago after rebuilding my carbs. It's been running like a champ since aside from the clacking hence my initiative to redo valve adjustment now suddenly here I am with high revs and cold #1 cylinder! I must have opened a leak somewhere but I sprayed around #1 real good. But in the morning I will try again very carefully and thoroughly


Help me understand how you get a high rev from a leak. I remember after cleaning my carbs at first I had cold pipes 1&3 then at some point crazy high revs I believe I cured with sealing boot leaks, but might have been slow jet re-cleaning. If I can understand better things I accidentally fix then I can better purposefully fix things in the future.

Thanks!

[Paintedseat]

Can't really help you without being there. If you have valves in spec, timing in spec, carbs are synchronized, and and you still have issues with 1 then it is another issue that will take some trial. Are you using a single vacuum gauge to set sync? If so

[crazypj]

Number one probably has some dirt is a jet or shut off blocked?
 It's more common when you use side-stand (or only have side-stand as it's 'lowest' so anything settles there.
Idle has gone up because number one is now holding the others open.
Wen doing tappets, watch intake rocker (actually it's easier to feel it) it goes down, comes back up, you will be TDCC on that cylinder when marks line up. Itisn't 100% 'to book' but it's safer to use 'Go-No Go' with 0.002" and 0.003" feeler for intake and 0.003"-0.004" exhaust, smaller size 'slides' in, larger size won't go

[juntjoo]

Number one probably has some dirt is a jet or shut off blocked?
 It's more common when you use side-stand (or only have side-stand as it's 'lowest' so anything settles there.
Idle has gone up because number one is now holding the others open.
Wen doing tappets, watch intake rocker (actually it's easier to feel it) it goes down, comes back up, you will be TDCC on that cylinder when marks line up. Itisn't 100% 'to book' but it's safer to use 'Go-No Go' with 0.002" and 0.003" feeler for intake and 0.003"-0.004" exhaust, smaller size 'slides' in, larger size won't go

Okay, I'll check for leaks once more then remove the bowl and clean up in there. Perhaps it's a stuck slide/cylinder(cv carbs)? I gotta get this today b4 I hand it over to mech tomorrow for tires...

[juntjoo]

And I'd call myself a certified valve clearance adjuster at this point. I even taped a long cable tie to the handle of the adjustment tool to line its end up to something(a scratch on the frame) to see if the screw moved while I wrenched it so I could do it in one shot. Kinda worked.

[TwoTired]

Did you look at the spark plug tip of the cold cylinder?  Dry? Wet?  Electrode shorted with soot?
searching for clues?

Or, continue with "twiddle and try"...

Good luck!

[juntjoo]

Did you look at the spark plug tip of the cold cylinder?  Dry? Wet?  Electrode shorted with soot?
searching for clues?

Or, continue with "twiddle and try"...

Good luck!

Thanks for commending me on my perseverance. Yeah, I know I'm awesome, now stop buttering me up. You're not too shabby yourself. Silly me, if I didn't note anything about my plugs as from my recent experience if it's not firing it's wet. Just me being green. Oops! Sorry! And yes, it's wet, my 1st impression would be from oil.

So I swapped idle screws of #1 with #4, no change.

Tried swapping both main and slow speed jets(only ones I've got) no go.

Lastly I swapped top parts(spring, slide, kidney gasket)with #4 and sprayed into holes. #1 was wet with fuel. Again no go. I also tried swapping wires with #4 completely AND just at the plugs. It gets spark definitely.

Probably what you'd expect but just to note, pulling the sync tool tube from #1 causes lots of air to pulse through and have zero effect on idle whereas other cylinders cause engine to bog and very slight air puffing through hole.

So now maybe I'm starting to wonder about timing. And nothing going on with choke. Barely need it now.

[juntjoo]

"twiddle and try"? You never twiddle and tried through life learning? So you were born brilliant? Oh no... you just do things the right way? What are you trying to say? You better than me? You think it's funny how I "twiddle". Hey Loyd, you ever been a bully? Just wondering  genius

[Paintedseat]

Have you checked compression

[juntjoo]

Have you checked compression

Yes, about a month ago and go this:

compression 1,2,3 & 4 https://imgur.com/a/MXrkx

compression after oil added 1,2,3 & 4 https://imgur.com/a/9uezu

which I thought concerning just going by the book but no one thought they were bad and someone insisted not and you're all more experienced than myself so... What do you think?

[juntjoo]

Well I don't think any of those readings explain cold #1 anyway at least

[crazypj]

OK, originally it was clicking and clacking and run very well on all  4?
 You re-set valve clearances and it dropped a cylinder?
Has the top end been apart? (re-done before you bought it even?)
The only time I've heard something similar, it wasn't valve clearance per-sey but top of valve was bent so stem was sticking in guide when set at correct clearance.

[juntjoo]

OK, originally it was clicking and clacking and run very well on all  4?
 You re-set valve clearances and it dropped a cylinder?
Has the top end been apart? (re-done before you bought it even?)
The only time I've heard something similar, it wasn't valve clearance per-sey but top of valve was bent so stem was sticking in guide when set at correct clearance.

That's what I'm worried about. Idk what PO did. I only removed head to release stuck spark plug socket, in doing so I re-did clearances but incorrectly(up til yesterday I was doing the 2nd valve set on "t-f 2.3" which is impossible, not both passes of "t-f 1.4" stuff if hard to follow!)  I shall inspect #1 valves clearances again since it's easy enough. Need a new set of gaskets by now tho.

So what if I need to take a closer look then? Order gasket set and take off top. I looked it over a while back. Not too bad. Aren't there specific caliper tools needed for a thorough check?

Should I go that deep or just first look for an obvious bent valve(never inspected one before)?

Anyone ever have their valve adjustments auto-self-adjust on you? Kept finding mine off after doing all by simple 'off the lobe' sight method. Book says 9-12lbs, I shot for 11 then re-checked THREE times.

Paying mech $150 to put on $150 tires, what's another $300, if I'm lucky, plus parts, $400... $800 total..

Or what is it, $250 parts, and another $250 for a machinist to do something?

[crazypj]

Uh oh.
The 500 and 550 are well known to need rubber bands to hold rocker arms up away from valve tips, can't remember if 650 is the same (only did a few of them way way back) but it sounds like they may be? I don't know if you can remove adjustment covers (again) and see if any of the valve stems look offset compared to the rocker arm? It would be pushed towards 'outside'
With 500/550 it's easier to see as spring retainer is closer to the cap opening but 650 has te top covers so may not be so easy to see.
If the guide isn't damaged you should probably use an angle grinder to cut valve stem, you won't be able to straighten it and pushing bent end through guide will certainly break something