Tappet tool in place, Rotate crank?

[1948man]

I think I remember reading something about this but couldn't find it. If you have the tappet tool in place with the bucket depressed, can you safely rotate the crank? The reason I ask is because I can't for the life of me get the tappet tool to "bite" when the crank is rotated for measuring the clearances for intakes 3 and 4. It's something about the beginning taper of the tool so that it wants to pull away from the cam as you get started. With the crank rotated about 90 degrees from this position (I'm trying to depress intake 3) I can easily get the tool in and depress the bucket. The problem is that I can't get the shim out with the lobe in that position. I figure if I rotated another 270 degrees back to the measuring position, I could get the shim out if the tappet tool stays in position. Am I making any sense?

 

[Nessism]

The reason I ask is because I can't for the life of me get the tappet tool to "bite" when the crank is rotated for measuring the clearances for intakes 3 and 4.

I don't understand this. What does "bite" mean in reference to the tappet tool? Is the tool slipping off the bucket? If so, use a small screwdriver along side the tappet tool to keep it from sliding off.

 

[DanTheMan]

I think I remember reading something about this but couldn't find it. If you have the tappet tool in place with the bucket depressed, can you safely rotate the crank? The reason I ask is because I can't for the life of me get the tappet tool to "bite" when the crank is rotated for measuring the clearances for intakes 3 and 4. It's something about the beginning taper of the tool so that it wants to pull away from the cam as you get started. With the crank rotated about 90 degrees from this position (I'm trying to depress intake 3) I can easily get the tool in and depress the bucket. The problem is that I can't get the shim out with the lobe in that position. I figure if I rotated another 270 degrees back to the measuring position, I could get the shim out if the tappet tool stays in position. Am I making any sense?

Yes, you're making sense. I put the tappet tool in when the bucket is depressed, get hold it in place then rotate the cam shafts. Works fine that way for me. Just make sure the bucket is aligned properly for shim removal.

 

[TeamDar]

Do not rotate the crank with the tool in place.

 

[1948man]

Thanks for the replies. Yes, by bite I was talking about it slipping off. My buckets seem to have an awful lot of taper and almost no "ledge" to grip on. Seems I actually have a different problem though. I think the reason I can't get the shim out has nothing to do with the position of the lobe. I think the shim is one with no little beveled edge on the bottom and it just doesn't want to come out. I've used the little screwdriver trick and it will cock up but come out yet. I checked to make sure it wasn't tight against the lobe and there is some clearance there. I also tried hooking it with a pick and it still didn't want to come out. Maybe if I harass it enough it will come out. The way I got the tappet tool in was to begin to lever it down slightly and then tap the curve of the tool lightly with a wrench handle to get it to stay in. Hard to describe in words but I'm not getting hamfisted.

 

[1948man]

Got it!! I pried it up as much as I could, then tapped it back down flat. Did that several times and it came out. I would still be interested in any debate as to whether it's safe to rotate the crank with the tool in place. There seem to be a couple of different opinions. It sure would it make it easier to get that finicky tool in. At any rate, thanks for the help. Jim M

 

[Steve]

Just use the "zip-tie method", it works great, won't slip out of place.

It also does not hold the valve open too far that you can't rotate the engine.

.

 

[1948man]

Yeah, I always seem to try to use the tool but I guess I'm going to have to try the zip-tie method. So if the bucket is depressed, that means valve to piston contact is a danger if the crank is rotated?

 

[chuck hahn]

Yes its a possibility if its into the cylinder far enough..but i think that as you rotate the engine and the cams turn, youll only dislodge the tool anyways and have the valve slam shut...and if theres a shim crooked in there you will most likely snap the shim. I personally wouldnt moveanything with the tool in there.

 

[Steve]

...and if theres a shim crooked in there you will most likely snap the shim.

Yep, and here is what it can look like:

This was on a Kawasaki, but the principle is the same.

.

 

[BassCliff]

Hi,

The trick to using the tappet tool is to take your time. Lubricate the round part of the tool. As you push the tool down to depress the bucket, maintain pressure against the cam so the rounded part glides around the cam shaft and is not "levering" or prying the bucket down.

I have, once or twice when a bucket was being particularly disagreeable, placed the tappet tool in position when the lobe had pressed the bucket down. I then rotated the cam 1/4 turn to leave the tool in place and remove the shim. But practice makes perfect once you get the feel for using the tappet tool.

I like Mr. Nessism's idea better, use a screwdriver to keep the tappet tool from slipping off the edge of the bucket.


Thank you for your indulgence,

BassCliff

 

[Normk]

It is certainly more than possible, "likely" is a better term, to bend a valve by rotating the crankshaft while the shim tool is installed. Absolutely no question that this can happen. In fact bending a valve is virtually guaranteed by doing so on some engines.

One has only to consider what is happening. The valves open and close in very close proximity to the piston crowns and the opposite valves at times. In some engines the intake valve(s) and exhaust valve(s) will come into contact if opened at the same time.

There are very few over head valve engines in which the valves will not contact the piston crown if valves are wide open while the piston comes through top dead centre.

Valve clearance checks are usually performed with the piston at TDC (Top Dead Centre) so piston to valve clearance is at its minimum which exascerbates the risk of over opening the valves. Regardless, the requirement for removing the shim is that there be more space/clearance created between bucket and camshaft in order to allow for the shim to be lifted and slipped out. A shim tool is simply a wedging device fashioned such that it presses the shim bucket downward and holds it in this position.

Placing the tool into place must open the valve, there is no other way to achieve clearance between bucket and camshaft lobe excepting to lift the camshaft. Open the valve and turn the engine is simply begging for a bent valve unless one knows that the piston is not in proximity.

While I am sure that those who have posted to this thread understand these factors, it may be that someone who is reading here does not. A bent valve is a nasty development....

 

[Guy]

It is certainly more than possible, "likely" is a better term, to bend a valve by rotating the crankshaft while the shim tool is installed. Absolutely no question that this can happen. In fact bending a valve is virtually guaranteed by doing so on some engines.

That ain't necessarily so. I have a shim removal tool I made myself, it holds the bucket down/valve open just enough to slip a shim out but not enough to let it contact the piston or opposite valve. I would think the suzuki tool will do the same job.

 

[Don-lo]

I think I'll encamp on the "likely " side, and raise the ante with the possiblilty of cracking a valve guide. Don't do it, it's not worth it, make the system work.

I know it's a delicate balance, but it does work. I have 2 different tools, and I admit that one works better than the other. Some people have ground the leading edge so it slides in place easier.

As far as the shim not coming out even with clearance, that is due to the tool edge being over the shim. The tool must be positioned out a smidge more so the tool stops where the shim starts. The shim needs to come straight up, then out.

 

[1948man]

I got the tool to work without rotating and hopefully won't be back in there for a while. After I buttoned everything up, I did grind the leading edge of the tool just a tiny bit and kind of polished up the working surface a little so it hopefully will get a better grip and stay in place a little better next time. My finesse seems to lag in the lapse from one valve adjustment and the next.

 

[Normk]

Even if there is sufficient clearance to allow the valve to be open far enough to clear the bucket so that the shim can be withdrawn, why take the risk of rotating the crankshaft? It certainly goes against best practice.

Clearances are very close in most engines and although some engines are not interference in terms of valve train, this still does not address the possibility of ash or carbon build-up. Block a valve open & rotate the crankshaft if you wish but, IMO, it would be irresponsible to recommend that someone do this if there is a viable alternative. The shim & bucket tools are intended to slip in and depress the bucket, or at least all the motorcycle and automotive ones I can recall are of that fashion.

Some engines require that the piston be positioned away from TDC because of clearance issues. Not wishing this to sound argumentative but see no reason to risk rotating the crankshaft with shim too; in place. I've seen some valves bent during adjustment and it's not a good thing. I'd feel very bad were someone to think that I'd recommended such a practice.

I may see this differently than do some but have worked professionally in the vehicle repair industry for many years so view things from that perspective.

That ain't necessarily so. I have a shim removal tool I made myself, it holds the bucket down/valve open just enough to slip a shim out but not enough to let it contact the piston or opposite valve. I would think the suzuki tool will do the same job.