Valves

[prometheus578]

"I forgot nothing..."

T.C.,

Prom, you forgot Sailor

Most people forget about sailors... what's to remember?
And squeeking of sailors... it seems that a certain ex-sailor has failed to remember his manners when speaking to a lady.

... the fact that you are also going to do a head job,

Uhmm.. mechanics call this a valve job, T.C.
Maybe not a sailor... but a gentleman would note the difference.

An offender of many sorts I might be... but "equal opportunity" offends even me.

Oh yeah, you mentioned price.
TRBIG just had a three angle valve cut done, and they resurfaced the head, all fer $110. I can imagine the prices elsewhere may be similar.

[randy]

Carolyn,

Should you decide to do the valve job yourself, I'd be glad to lend you my valve compressor set. I only use every few years anyway!

I'll even throw in the slightly used tube of lapping compound, that stuff goes a long way!

Let me know, PM me and I'll ship it out.

[prometheus578]

"Tryin' to weasle in, huh?"

Back off, Randy... I saw her first!

[CarolynS]

Boys! Boys!

In the immortal words of Scarlett O'Hara, "I always could depend on the the 'khindness of strainjahs'".

[CarolynS]

Checked cam 'dots'

They line up. Each side. The dot next to the center bearing keeper just before the cam chain. It took me a second to find it, but I did. Both are straight up with the timing mark at 'T'.
One thing I did notice though, someone has messed with the screws that hold-what I would call-the 'timing indicator plate'. I don't know the name and I'm not going to look it up now. So much so that the screws are stripped out. Is that how you advance the engine timing? It's strange that someone would strip them out like that, at least someone that has a clue wouldn't do that. If I strip a screw, I replace it even if it means I have to drop what I'm doing and go get another.
So what now?
Looks like valve lapping may be in my future. Unless you guys can think of something that could cause all of this due to someone messing with the timing. Remember, no compression.
Wait a minute! The person who did the compression was HWMBO. He may have screwed it up. He thought I was crazy to go and buy a gauge. I may redo it-the right way-just to recheck.
Do you guys think that may be possible? The timing could be way off and that's the problem? If he did this on purpose, I'll kill him!

[oldnortonrider]

Those bolt heads that you're referring to, that look like they've been tampered with, hold the pick-up base plate~~on some models they were "sabotaged" at the factory, on purpose, so the owner couldn't alter the timing (EPA). The Clymer manual shows (pages 250-252) how to drill 'em out, and put "workable" bolt/screws in. Your problem(s), for now, have to do with the valve/cam timing. Not the ignition timing~base plate. When "the dots" were lined up per above posting, you've got another mark that supposed to line up at the same time~~an arm down below, in that same base plate location sticks out with a mark on it, and aims at a timing wheel, with letters T and C on it. On one of the turns when "your cam dots", up above, line up~~the "stationary fixed-pointer arm with its mark is supposed be aimed at the "T" on the timing wheel below. I'm guessin' the pointer arm is gonna be off~~probably 1/4 to 1/2 inch~~10-20-30 degrees, for the valves to have hit the piston, which they had to have done, for you to have the shim/cam clearance that you've got. The dots and arm/timing wheel mark (T) line up on every other rotation. Rotate clockwise~~looking at it. The manuals do help on this; they don't cover everything; but they touch on everything I'm covering here. And they've got pictures. The dealer's manual covers different things, also. Combine the two with this forum, and yer home free. Can't get the Haynes manual, or I'd have it, too.

[CarolynS]

Tampering

No, these are shiny, like someone did them yesterday, and the outsides of the screws are scratched up-I watch CSI, it's evidence!-LOL! The factory wouldn't have used vise-grips on the outside of the screw-like to break it free.
The timing mark(T)lines up perfectly, no deviation. I made sure I had it dead nuts. I don't want to pull the heads off of 2 bikes for nothing!
I will try tomorrow to rotate it all the way around and see, but I don't know what difference that makes. Honestly, I'm not being a smarta$$. I did turn it all the way around, which was way too easy considering the plugs are still in-no push required-so still no compression, not that it would'be changed.
I am just so hoping that it's something stupid, something I've missed...But it's becoming clear that it probably isn't. I just found it strange that someone would tamper with the plate settings.

[oldnortonrider]

Actually, the way the factory "sabatoges" those screws, is that part(s) of the screws' heads twist off when torqued~~meaning that if one did try to loosen them, they'd only be left with what would have to be gotten hold of with vise-grips; failing that~~next step would have to be to left-drill 'em out.

You say the dots, and the T-mark line up? on the money.
You gotta manual?
Was that valve-shim clearance 25 thousandths (of an inch) or 2.5mm, or "what", exactly, again. I believe you originally said ".24-.25".......................on all 8 valves.................(?)...................

[TopCatGr58]

Hey Carolyn,

What Norton is saying is TRUE. In 80, Yamaha used BREAK OFF bolts inside plastic lipped washers to SECURE the timing plate at the proper factory setting!! Now, perhaps the PO removed them, but didn't bother to put new ones back in??

Now, I had a FLASH THOUGHT about this. Okay, the timing marks line up so no "evidence" of a slipped cam chain, yet you have what seems to be 4 bent valves.

There is a recent thread about what can happen when you OVERREV these engines, floating the valves and slamming pistons against them bending them????? So now I surmize, deduce, that perhaps this is what has happened to it!?

These machines don't have rev limiters built into the TCI's like the modern bikes, and so if the PO misshifted, hit neutral, etc., could have tach'd it past 9krpm and bing, bang, bendo!

I made sure I had it dead nuts. I don't want to pull the heads off of 2 bikes for nothing!

Doing a "head job" with dead nuts seems futile!

Sorry Carolyn, couldn't resist....I still respect you but a good jab is difficult to pass up....just ask PROM!
T.C.

[CarolynS]

Valves

The clearance is .25 or more mm.
No, these screws are intact with vise-grip marks on them. Like the one on my carbs that was stubborn and I had to clamp down with the vise-grip and use the screw driver to break it free, after liberally dousing it with liquid wrench.
I have the Clymers, Prometheus, and TopCat, plus others. I can't get any more educated than that!LOL. And they DO line up, perfectly. I was really hoping they wouldn't. That would've been too easy. Not in this order-Get TDC, readjust everything, pray, and fire!
Remember, no compression at all.

[oldnortonrider]

TopCat; that's "EIGHT"!! bent valves~~all with those giant clearances..............................??!!

[CarolynS]

Wow!

TC! You CAD!!!!

[prometheus578]

Doing a "head job" with dead nuts seems futile!

Just the type of comment i'd expect from an ex-"seaman".

[CarolynS]

So what now?
Advise me, oh noble ones...
OldNorton(which may I add, is one of my favorite motorcycles of all time; even better when made a 'Triton')I understand what you're saying, but I've never seen this bike run; the 'kid' and I do mean kid, I bought it from had no idea what he had or how to make it work, much less appreciate it if he did manage to get it going;my other one runs, but is a nightmare.
I am just trying to save myself the horror of pulling things apart only to find it was some moronic(or moron)thing that was done or undone that caused this. The 80 is in unbelieveable shape-dealer maintained condition-and I find it hard to believe that something terrible happened to it.
God, I wish they could talk....

[TopCatGr58]

Re: Wow!

Originally posted by CarolynS
TC! You CAD!!!!

That's Computer Aided Deviant !

Well, Norton, it does seem a stretch for ALL 8 valves to get bent, it's usually the Intakes IIRC that get it due to them still remaining open while the piston is rushing up for the compression stroke, but I think the exhaust could do the same thing during the exhaust stroke, at 9+k rpm, things are happening very fast!

I hate to say it Carolyn, but sometimes there's no other choice than surgery to find out what's going on inside. I think we've exhausted...no pun intended...the other diagnostic checks for the OTHER causes of zero compression and extreme clearances.

IT's known that the clearances actually reduce over time due to the valves sinking farther up into the seat and if they get too close, then the valves don't close completely, and the sealing surfaces can get burnt, pitted, etc. causing poor compression and performance. But again, I don't know if this could occur to all 8 valves to the same extent to create zero compression on all four!?

My other thought is some form of severe buildup around the valve below the head, like excessive carbon, etc., that is causing the valves to stick, not close completely!?

I say, take the 80 apart first, and find out what really happened. THEN IF you find just bent valves vs. holes in pistons, then you cna proceed with the head transplant. But if more severe damage like piston holes is found, then you can just transplant the entire 79 engine to get it up and running as quickly as possible!
T.C.