Help: front cylinder valve adjustment

[Herb]

I'm adjusting valves again but am having a snag with e the front valves. When I crank the shaft counter clockwise until the FT marl aligns the valves are still tight. Can't get a feeler Gage in there. I've rotated the crank several more times but same result. The only time the valves are loose is when there is no fly wheel mark in sight. What's up? What am I missing? Had no problem with the reR RT mark.

 

[Rich]

What I would do is loosen the valve adjustment screws. It might be you're down close to or at zero clearance right now.

 

[Rmcapozzi]

If the crank is in the correct position, what you are looking for next is confirmation of the correct position and that can be done by checking for looseness of the valve (not clearance at this point). If the valve has some slack (you can move the rocker a little bit) then you can be sure that the crank is in the correct position. The manual says if you are aligned with the FT mark and there isn't any slack, rotate the crank 360 degrees (counter clockwise) and check again. You may be at the TDC but not on the compression stroke.

At that point you can check for clearance. If you can't get a feeler gauge of the correct thickness in there, drop the feeler gauge size until one does. When you find one that will slip in, that is what the current clearance is. If that isn't within spec then you need to adjust the valve.

I'm adjusting valves again but am having a snag with e the front valves. When I crank the shaft counter clockwise until the FT marl aligns the valves are still tight. Can't get a feeler Gage in there. I've rotated the crank several more times but same result. The only time the valves are loose is when there is no fly wheel mark in sight. What's up? What am I missing? Had no problem with the reR RT mark.

 

[Rich]

The only time the valves are loose is when there is no fly wheel mark in sight.

On rereading I saw I missed this very mystifying data point. I don't know what to think. They would be somewhat loose with the piston near (and not quite at) TDC, but if so they absolutely should be loose at TDC in the exhaust-intake transition phase. The condition you describe suggests a mismarked (or loose ) flywheel or something out of whack with the crank-cam drive train (also ).

You say you're doing it again, so I presume you've done this before with no surprises?

 

[mikesim]

Here's a trick that may help you figure it out. Rotate the flywheel while you are looking at the "intake" valves of the cylinder you are wanting to adjust. When the intake valves go down begin watching for the correct mark to appear. When it does, you are there. At that point, all the rockers on the cylinder should be somewhat loose. That's TDC for that cylinder and that's the point that valve clearance should be checked/adjusted for that cylinder.

Hope this helps!

Mike

 

[DirtFlier]

Mike's suggestion was sound but I make it even simplier. I rotate the crank until "FT" (for example) is showing in the window, then try to move all the rocker arms for the front cyl.

If some of them are tight without clearance - it's on TDC exhaust so turn the crank another 360 until you can see the FT, and recheck.

If all of them have clearance - it's on TDC compression and you can adjust.

 

[seagrass]

I have had this problem (on another bike not an NT700 and with cars) when I was rotating the crankshaft in the wrong direction.

I am not sure which way you need to turn the NT crankshaft (as I am not picking up my NT until next Thursday and I do not have a workshop manual yet) but I just thought I would mention this in case it may be the problem

 

[ARKNT]

Other than rechecking and rotating 360 degrees and rechecking for looseness it sounds like a sheared key on the flywheel or cam but that seems very unlikely. I would go through it again (which you already have done) being extra careful and looking for something that doesn't look right. Also recheck the rear clyn. If the marks still line up then the flywheel should be in the right position, including the flywheel key.
Is the cam chain tight?

Brad

 

[Herb]

Well, I got frustrated and called it a day...it was getting dark anyway. I must have done 20+ counter clockwise rotations to the FT mark and still found the valve assembly tight and not able to get a feeler gage of any sort in. If I rotated and looked at the intake valves depress and then return, they were loose then but not on the FT mark. I'll go back to it tomorrow morning. Really weird. I'll go back and recheck the rear which went fine and lined up on the RT mark. Bed time.

 

[ARKNT]

Good luck Herb,
It sounds like a strange problem. I have had problems with maint before and leaving it to the next day helped. Fresh start.

Brad

 

[Herb]

No luck or skill or whatever. Front cyc values are still tight when the crank is on the FT mark. I tried loosening the valves but got to the end of the loosening cycle(couldn't go any further) and they were still so tight couldn't get a gage inserted.

I rechecked the rear and it's fine... what? Looks like I'm going to have to ship to a shop!

 

[ARKNT]

Sorry about the valve check Herb,
You are using the FT mark and not the F mark. I know you stated that in your posts, but they are similar looking and something strange seems to have occured to your valves/cams.
Attached is a pic of the flywheel and front marks.

Good Luck,
Brad

 

[Herb]

Hi Brad,

Yes, I'm using the FT mark. Can I give you a call by the looks of your fly wheel pict you seem to know what you're doing. Can you PM me with phone number.

My front valves only seem loose when closer to the RT mark!?!?

 

[DirtFlier]

[...must have done 20+ counter clockwise rotations to the FT mark...] You'd better order some piston rings because you're worn-out the dang engine!

All kidding aside, get a good night's rest and hit it again in the morning. Out of curiosity, did you remove the spark plugs? I find that getting the engine to stop at TDC compression (FT or RT) is much, much easier with the plugs removed. With plugs installed, the engine doesn't want to stop at TDC compression. What is does is get difficult to turn then suddenly it'll jump forward and you'll be beyond the mark.

 

[seagrass]

If the mark is lining up properly on the rear cylinder and the bike was running OK before you started this maintenance then it appears most likely that you are not using the correct mark to line up the front cylinder.

It may help to remove the spark plug from the front cylinder (if you have not already done so) and then have a friend look in the spark plug hole (using a torch and mirror if necessary) as you turn the crankshaft in the correct direction.

When the piston is at the highest point, check the mark on the fly wheel for alignment and check the valve rocker clearence, if it is still tight, rotate the crankshaft one complete turn and check again.

Seagrass

 

[ARKNT]

Herb,
If you are still having trouble and the NT is disasembled look at the cam install section of the manual (page 9-30).
There is an "F" stamped on the front camshaft next to the cam chain sprocket. It should be facing up when the "FT" mark on the flywheel is aligned and the valves are ready to be adjusted. If not up then rotate crank 360 degrees. The "F" should now be facing up. If it is not straight up there may be a problem.
Just some more info to look at.

Brad

 

[DirtFlier]

[...There is an "F" stamped on the front camshaft next to the cam chain sprocket....The "F" should now be facing up. If it is not straight up there may be a problem..."]

As far as I know, the motorcycle ran the day prior to Herb starting the valve adj procedure so it's highly unlikely that the cam timing has changed. If the cam timing is off, the engine generally doesn't run.

 

[EX Winger]

Herb, DON'T loosen anything until you establish TOP DEAD CENTER on the compression stroke.

Your sparkplugs should be removed for this valve adjustment procedure because it makes it much easier to turn the engine over.

Get a 3/8 inch wood dowel or a pencil and put it in the sparkplug hole. Watch it go up and down as you turn the engine over slowly. You can easily see the point when there is NO movement---that is top dead center for that cylinder.

At this point, look to see if all valves on that cylinder (Intake and exhaust) are closed, with the valve springs at the same height, not compressed. At this point, you should be able to feel some movement. This is when you check to see the clearence. If you have the piston at top dead center and either the intake or the exhaust valves and their springs are compressed then that cylinder isn't at top dead center on the compression stroke where all valves are closed for that cylinder.

If you use the dowel/ pencil trick, you don't need marks on the flywheel or cranhshaft.

Sam

+1, +1 on what Sam has said here. He has put it in the most simple way it is possible to be said.

I had a similar problem with valve check on GL1800,it drove me crazy until I quit trying to follow the book and simply made sure the piston was AT top dead center , then every ting worked out with no problem.

Eldon

 

[Herb]

Herb, DON'T loosen anything until you establish TOP DEAD CENTER on the compression stroke.

Your sparkplugs should be removed for this valve adjustment procedure because it makes it much easier to turn the engine over.

Get a 3/8 inch wood dowel or a pencil and put it in the sparkplug hole. Watch it go up and down as you turn the engine over slowly. You can easily see the point when there is NO movement---that is top dead center for that cylinder.

At this point, look to see if all valves on that cylinder (Intake and exhaust) are closed, with the valve springs at the same height, not compressed. At this point, you should be able to feel some movement. This is when you check to see the clearence. If you have the piston at top dead center and either the intake or the exhaust valves and their springs are compressed then that cylinder isn't at top dead center on the compression stroke where all valves are closed for that cylinder.

If you use the dowel/ pencil trick, you don't need marks on the flywheel or cranhshaft.

Sam

Ah, here's the update.... I haven't had the heart to respond since Sat... Too depressing, I think.

I kept turning and turning and checking and checking until I one time... At least in my mind everything seemed to line up(FT mark and valves loose). I jumped on it and adjusted the valves, closed everything up and fired it up. Disaster.. Clanking, misfiring... Shut it off and reopened everything(I'm willing to bet that I'm the quickest guy in the country getting the NT valves exposed- practice makes perfect). It must have been wishful thinking, cuz it was back to the FT mark indicating impossibly tight valves- totally off as before. I finally gave up on the FT mark after talking to Brad and essentially did what Sam suggested here ignoring the FT mark. Closed it up. Fired it up. It sounded good.... Except I THINK I'm hearing a knocking noise that was not there before. I say "think" because I'm not sure it's really there or my head telling me that I screwed up and messed up a valve on my earlier try.

I didn't ride today given my fears. I'm thinking i need to take to a trusted mechanic and have a couple of names. Thoughts and advice?

 

[rcase13]

I was all set to do this on my bike but now maybe I won't. My bike had 2100 miles on it when I bought it and I have no idea if the 600m inspection was performed or not.

I would not think it's possible to adjust a valve to the point where it touches the piston head. The fact that it runs to me means it's probably fine. I've adjusted valves before but never on a motorcycle. Are motorcycle engines different than other small engines? In my experience you can adjust a valve to the point the engine doesn't run but you couldn't actually cause damage. To cause damage you would have to actually disassemble the cam chain and move a cam. That was not done in this case. For piece of mind I would take it to the Honda dealer and pay a 4 hour inspection fee. They can do as others have said and do compression checks to make sure everything is seating properly.

Thanks for posting your woes. This is how we can all learn. Don't feel bad we have all made mistakes it's part of being a home mechanic. Yesterday I dropped a socket down into my fuel tank on my NT...