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Valve clearance


RC36B

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Short Update: received the new shims, installed them and swapped one shim to another location.  Put the cams in, rotated engine, checked all valves again and found that #4 inside intake was WAY too tight at about 0.003".  Removed the intake cam, checked the shim and I had written the initial shim measurement down incorrectly, so my calculation for the new shim was wrong.  Re-calculated and found that one of the shims I had removed would work.  So in it went then the cam.  Rechecked and all is good now.  Just waiting for the Hondabond HT sealant to arrive.  Gives me time to do additional cleaning and besides it is too cool to ride anyways.

Thanks for all the help.

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6 hours ago, Lannyl81 said:

Short Update: received the new shims, installed them and swapped one shim to another location.  Put the cams in, rotated engine, checked all valves again and found that #4 inside intake was WAY too tight at about 0.003".  Removed the intake cam, checked the shim and I had written the initial shim measurement down incorrectly, so my calculation for the new shim was wrong.  Re-calculated and found that one of the shims I had removed would work.  So in it went then the cam.  Rechecked and all is good now.  Just waiting for the Hondabond HT sealant to arrive.  Gives me time to do additional cleaning and besides it is too cool to ride anyways.

Thanks for all the help.

Perfect 🙂 

 

Yeah - I use an Excel spreadsheet that reuse shims (priority is something like 1. on same cam, 2. on adjacent cam and 3. other cams) to get best gap and lowest number of new shims. Removed shims is automatically moved to stock so they may be used next time further reducing new shims.

Of course I still need to measure correctly 🙂

 

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13 hours ago, RC36B said:

 

Of course I still need to measure correctly 🙂

 

That's the tricky part, what exactly does a 'light sliding fit' feel like when the feeler gauge has to be bent to get it into the gap on some valves, but can go in straight on others?

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20 hours ago, daved said:

That's the tricky part, what exactly does a 'light sliding fit' feel like when the feeler gauge has to be bent to get it into the gap on some valves, but can go in straight on others?

 

It can be. It helped when I replaced my feeler gauge with a slightly more "slim" version with longer blades. Less force needed to bend and easier to use same bend throughout.

 

I start with too thick gauge - it is easy to feel when it is a "brick wall". Move down in thichness and you find the thickness to be tight, and where next is loose. I choose the thickness of the tight fit.

Sometimes it goes from "brick wall" to loose - then I use a thickness in between.

 

I work 4 ports at the time... feel them all with a thick blade combination. If all valves are "brick wall", reduce and try again. At som point you get to the thickness of one gap, the I continue work on 3 valves left... and so on. In this way it takes only a few minutes to do them all.

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On 10/1/2019 at 10:49 AM, Mohawk said:

Look up the bucket & shim record method. Basically check every valves clearance. Record it against each valves location on a table. Then if you have to remove the cams to change one, you can compare shims from a tight ish valve & a loose one. Often you can switch them around to get a middle of the road clearance. So no mew shims needed, or less of them at least. 

 

Get yourself a magnetic picker tool to lift the buckets. Often that will lift the shim too ! 

 

And remember the cam anti lash gear painting BEFORE. you lift a cam. It really does make refitting much simpler.

 

Have fun.

This is a very good thread. Last checked my valves 16K miles ago, all were in spec but some on the edge. Bikes got 82K miles ( 132,000 km) on it now and think I may need to replace a few shims this time. Not ever having to do a bucket and shim adjustment as most of my bikes are older, I have been reading up as well I can on it. But I'm curious about the statement in the post above about painting the anti lash gear before removal. I assume its to index the gears, but what do you use? I've used grease  pencils as markers and whiteout when we all used typewriters in the past, but is there something I need to know. Any advice on this would be helpful. Actually any advice on this process would be appreciated. I've assumed things on my bike in the past that have ended me up in the Hospital for 4 days 1300 miles from home.  Worse yet I've assumed a few things that have made me the topic of conversation around the fire with a few beers 🙂 So, please feel free to chime in with any advice. Thanks.

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I just used whiteout on the gears; I also put a matching mark on the cam. The photo is of my ST1100 but the prinicple is the same. You will find on reassembly that the marks will look a little off until you tighten down the cam holder saddles which moves the tension spring within the gear. 

IMG_2601.jpg

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Thanks Terry:

 

Had a look, whiteout stills seem to be available despite my last bottle drying out years ago, I'll order one.

 

Also seems to be a lot of stuff called "Correction Tape" online. Seems to be the PC way to say I made a mistake without actually saying I made a mistake. Never saw it before.

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29 minutes ago, Terry said:

I just used whiteout on the gears; I also put a matching mark on the cam. The photo is of my ST1100 but the prinicple is the same. You will find on reassembly that the marks will look a little off until you tighten down the cam holder saddles which moves the tension spring within the gear. 

IMG_2601.jpg

I'm curious if anyone knows (no mention in the FSM I can find) if one loses the reference points on the gears how to find them again.  When removed the gears seem virtually impossible to move relative to each other by hand.  The gears lining back up as described when tightening things down seems to make it somewhat foolproof - could they "go the wrong direction" and actually loosen the spring tension vs being correct (it doesn't seem so . . . ).    I too marked the gears prior to removal but after reassembly I began doubting myself - "did I get that back together correctly??" so just wondering if there is any way of definitively doing it the way Honda did from scratch. 

 

 

 

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7 hours ago, Cogswell said:

I'm curious if anyone knows (no mention in the FSM I can find) if one loses the reference points on the gears how to find them again

The gears are stamped so no problem. Even if you removed all cams and got lost on position, the shop manual have an easy to follow procedure (shop manual 61MZ700 from page 8-21 (Camshaft installation) onwards).

 

Cams have both "marks" (line) and "arrows" - Honda use the "marks" for the rear cylinders and arrows for the front cylinders.

 

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12 hours ago, RC36B said:

The gears are stamped so no problem. Even if you removed all cams and got lost on position, the shop manual have an easy to follow procedure (shop manual 61MZ700 from page 8-21 (Camshaft installation) onwards).

 

Cams have both "marks" (line) and "arrows" - Honda use the "marks" for the rear cylinders and arrows for the front cylinders.

 

 

I wasn't referring to the timing marks - I'm referring to how the narrow and wide gears (photo above) move relative to each other after removal and Honda specs matching the gears back up upon re-installing - nothing to do with timing.  I believe it's the smaller gear that is spring tensioned and that needs to be correct relative to the drive gear to eliminate backlash.  That's why there are 3 white lines on the photo rather than just 2 . . . AFAIK it's possible to having the timing marks lined up with the heads and crank correctly but not have the two gears lined up correctly relative to each other.  It's only briefly mentioned in the FSM, but I can find no detail.

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6 hours ago, Cogswell said:

I'm referring to how the narrow and wide gears (photo above)

The gears - once removed - will relax in a “neutral” un-tensioned position, which is about half a tooth off. 

So the answer is “no” - you are imagining  a problem which does not exist 😉
 

So when torqued down Newton's third law takes care of the gears final position. You need to check timing marks AFTER torqued (especially for front cams).

 

If you look at below photo you can see the geometry only will allow for aligning gears in one direction... the gear from the cassette only fits the wide slot.

871976386_VFR750cam.thumb.png.7c54e829de3c43ad8d6094cae1c9ede6.png

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