Topic: Valves way too tight--anything I should be concerned about?

[jdigga]

I've been working to solve my hard cold start problem...

Yesterday I pulled the carbs (for the second time) to pull and clean the slow jets.  Sure enough 3 and 4 were clogged.  Thought that would fix the hard cold start, but no joy.  It was running so rich I could see the cloud of fumes ejecting from the exhaust pipes.

Today I decided to do the valve adjustment procedure.  The thing that struck me was that my valves had absolutely NO clearance whatsoever.  I had to loosen the tappet screws at least 1-2 turns each.

Well, I got everything back together and also adjusted the cam chain, and the bike started with much less drama.  Still had to fiddle with the idle, but the mixture was much better.  Engine sounded completely different--much quieter, no gnashing noises, much less vibration.

My big question is if there could have been any damage done by running with the valves so tight?  I've only put a couple hundred miles on it since I got it, and I did a couple high-RPM runs on the highway to loosen things up.   But the PO said it's always been hard to start cold and he put around 6,000 miles on it.  I'm apt to believe that he never had a valve adjustment done.  As far as the PO before him, I can't even speculate.  I'm fearing a Pandora's Box--after my test ride I found a new head gasket leak AND I blew the main fuse and had to walk it home (luckily I was only a couple blocks away).

On a different note, I'm amazed by the difference .0002 or .0003 inches makes.

[MRieck]

Tight valves always make cold starting hard as you can't build the compression necessary. You ride around long enough with no clearance and you'll burn an exhaust valve.

[jdigga]

Hmm, makes sense then that I went from oil just seeping from head gasket to a full-on drip. 

[DaveInTexas]

I don't know crap about mc engines but if the tappet clearances go away in some engines its because the valves are sitting very low on the seats....and something is wearing out.

[Big Jay]

If the valves keep tightening up on you, the valve head could be sucking up into the seat. Seen that on 750s before.

Jay

[kuyarico]

Did you check to see if the rocker arms were loose, to verify that you had the correct cylinder at TDC?

[eurban]

Kuyarico-  I think his point is that even with the correct engine position, the rockers were still under tension. . . . .Hopefully he was checking at the proper engine position.

[jdigga]

I rotated the engine to line up the T1.4 mark, found no play in either rocker in cylinder 1, rotated it 360, still found no play.  Did I use the right mark?

[TomC]

Hi Jdigga
     That you did not find any valves with Clarence, an I correct in that?, and that you turned the the adjusting screws one to two turns to get Clarence makes me think that you adjusted the valves with the engine 360 degrees out. That the engine is running better and is not making a lot of noise makes me think that you did it right.
     Turn the engine to the t1.4 mark. If the valves on 1 have no clearance the valves on 4 will have clearance. If the valves on both cylinders have clearance the valves are adjusted wrong. If this is the case turn the engine 1/4 turn in the running direction. Look at the intake valves. Which intake valve is wide open? One should be. The other should be closed with valve clearance. Turn the engine to t1.4, in the running direction. The cylinder that had the open intake valve is now at TDC on compression. Adjust it's valves and procede with the rest of the valve adjustment.
          TomC

[crazypj]

Today I decided to do the valve adjustment procedure.  The thing that struck me was that my valves had absolutely NO clearance whatsoever.  I had to loosen the tappet screws at least 1-2 turns each.


My big question is if there could have been any damage done by running with the valves so tight? 

On a different note, I'm amazed by the difference .0002 or .0003 inches makes.

If I'm getting this right it wouldn't run at all when you got it?
If it would start and run there is no way you could have loosened valves by 1or 2 turns and been in the correct position.
You need to watch the intake valve.
 When it comes up from intake stroke your getting to top dead centre compression (where its going to fire) and you do either cyl 1 or 4 whichever it is.
sequence will be,
TDC 1.4 on crank marks
 do either
 cyl 1 in/ex,
 cyl 2 ex. only,
 cyl 3 in. only
 cyl 4 both tight, don't touch.
 Rotate engine 360 degrees and do
 cyl 4 in/ex,
 cyl 3 ex. only
 cyl 2 in. only
 cyl 1 don't touch, on overlap
 It may be easier if you draw out 8 circles in two rows (adjuster pattern) and mark them intake/exhaust so you can see which 4 your adjusting at any point
PJ

[jdigga]

Tom: in preparing for the procedure, I rotated the engien through 360 several times to T1.4 but could not find any play in cylinder 1.  I'll try your procedure to double check.

PJ: When I got it, it was hard to start cold (I rode it home).  Had to hold the throttle a bit, even went so far as to use the car to boost the battery a bit.  Once it started I had to hold the throttle at 3,000 RPM or higher or it would stall out.  After it was warm, it would start just fine but was noisy as hell.  So I thought it was clogged slow jets or a carb sync issue.  Cleaning the slow jets didn't help.

I went by the recent article in Classic Bike that had the handy diagram of which valves to adjust, but I wasn't able to get a feeler gauge in anywhere unless I loosened the tappet screws first.

Even though it's running much better, I think I need to do the adjustment again to make sure.

[dusterdude]

if your valves are too tight,you stand a real chance of buring valves

[jdigga]

What concerns me is that the bike was run that way long before it came into my possession.  I think a tear-down is on the horizon.

[TwoTired]

What concerns me is that the bike was run that way long before it came into my possession.  I think a tear-down is on the horizon.

You might want to do a simple compression test before spreading parts all over your garage.

[jdigga]

I should have said "distant horizon".    I think I want to see how it runs when everything is adjust properly.  Eventually, though, I'll have to dive in there and replace some bits.

Do you think a re-torque will cure the head gasket leak?  It worked on my 650.

[crazypj]

I should have said "distant horizon".    I think I want to see how it runs when everything is adjust properly.  Eventually, though, I'll have to dive in there and replace some bits.

Do you think a re-torque will cure the head gasket leak?  It worked on my 650.

Very doubtful. The 'o' rings usually harden and keep leaking. Loosen each nut before re-torquing or you'll probably snap studs
 I would try setting valve clearance about 0.001" bigger than stock as valves may hammer into head and re-seal.
You can then run it to see exactly what you want to do.
PJ

[Gordon]

Do you think a re-torque will cure the head gasket leak?  It worked on my 650.

The biggest problem with that solution is that re-torquing the head requires removing the engine first.  Unless you want to do the frame cut mod. 

[nteek754]

Hey there  no  Idigga bite the bullet and put a new head gasket in hey you gotta pull the engine to torque the head anyway wll that is if you dont cut the frame  oops I dont want to open that can ofworms but ead I really doubt  a  retorque would do what you hope and then you would have to go all through it again  hope this helps seven fifty four ever Craig in Maine

[Master Ted]

FWIW, no play is a classic sign that proper attention/maint. has not been performed. Many lay people think wear is reflected by loose tappets when in fact the reverse is true. As the valves sink deeper into the head with wear between seats and valve flange the tolerance at the tappet closes.

Sorry to be a spook about it but this is not a positive indication bike was well cared for.

[crazypj]

FWIW, no play is a classic sign that proper attention/maint. has not been performed. Many lay people think wear is reflected by loose tappets when in fact the reverse is true. As the valves sink deeper into the head with wear between seats and valve flange the tolerance at the tappet closes.

Sorry to be a spook about it but this is not a positive indication bike was well cared for.

 Thats correct for shimmed tappets due to line instead of point contact with screw adjusters. The surface area and lubrication helps to dictate wear patterns. Screw adjustes wear faster than valve seats so they loosen up.
PJ

[jdigga]

Oh boy, can of worms indeed.  Does that mean new valves or head work?  Or both? 

[Master Ted]

PJ, when it comes to these specific engines common sense tells me to defer to those with much greater experience. But (there it is), A Toyota 22RE will do exactly as I've described and it also has adjustable tappets. My experience with a host of inline fours has been the seats will wear faster than the adjusters.

Anyone else? when a valve adjustment is necessary for these engines do you generally have to loosen or tighten the adjustment?

[MRieck]

Guys.... I know a leakdown test is always better for engine diagnosis

[Big Jay]

I would say that as the seat wears in and / or the valve face takes a pounding into the seat, the clearance will close up. As the cam lobe or contact area on the rocker arm wears, clearance will loosen up.

Jay

[HondaMan]

My experience here is a cross between MRieck and PJ: if the valves were too tight for a long time and the engine runs rich (which it then tends to do), the valves build up quite a layer of crud on their faces. If done gently, PJ's fix sometimes works: I've set the valves to be .004 (intakes) and .006 (exhausts) and driven the bike(s) for about 100 miles, then rechecked, to see if the clearance narrowed. A surprising number of times, this has cleaned the face of the valves and the owner went several more seasons of riding before an exhaust valve finally became a problem.

The exhausts will not clean as well as the intakes, cleaning off rather in little chunks. These chunks allow tiny grooves of hot gases to work on the face of the valve until eventually it burns a little groove out: a burnt valve. If you're lucky, they will clean off OK, I've seen that, too, un bikes that we're flogged much.

The only way to ultimately tell is a good compression check, but watch the clearances first for a while: if they narrow down, add some more clearance until this process "settles down" and doesn't move within 100 miles from your last check. Then do the compression test with the clearances set at .002" and .003". See if the cylinders are within 10 PSI of each other, and if so, maybe start thinking of buying the parts for the day when the valves will finally need some attention. If the difference is more than that, you might want to move a little sooner.

In the meantime, enjoy the ride!