Valve Tappet too Small 1.6-1.8mm?

[Dan Ruddock]

Don't waist your time. Get a head, with 38 years of engine building experiance I say that head is done and now I am done. Dan

[Roland]

Valve # 1 beyond spec.

P.S. Here is the replaced Cap in position eliminating the vertical play I had before.

[Dan Ruddock]

Your going to get more metal in your oil with that scored up cam journal. The cap cannot be aligned with the head because they were not machined together as a unit. If that waisted cam and head journal seizes it will snap the cam or chain, valves will hit the pistons and will turn a lot more of your engine into junk. If you don't care about what happens to your engine go ahead. Dan

[zathros]

If you want to make sure, get some Plasti-Gauge and place it on the camshaft and torque the cape.

http://www.plastigaugeusa.com/

If the clearance is the same all the way around the plastic strip will show it. It will also show exactly where the camshaft cap sits.

I believe you have an oil supply issue for the cam journal and cap to seize up like that. You should check and see that the oil is flowing where it should be. If the cap was off you could machine the bolt holes oval (ON A MILLING MACHINE) and once in place torque it up. This is what i would do in a post apocalyptic world, in the middle of the dessert or something to that effect.

You could probably get a whole engine a lot cheaper than you think and since everything else (carbs, etc) work, it would be a better route. I can believe with all that metal flowing around and a possible plugged up oil passage way, the rest of the motor is in much better shape. Good Luck to you. If you go for it it could last for quite a while before catastrophic engine failure. Just keep a couple of fingers on the clutch in case of motor seizure.

[Don-lo]

Yup, get a used head and cams. There should be plenty at motorcycle salvage yards. Check it first. $50 is a fair price.

[chef1366]

When you're done sanding the cam journals start sanding the shims.
Good luck.

[zathros]

Being disabled and unemployable, I also try and save on everything I do. I have a small machine shop but still know when to call it quits. You'll spend more on that head than a good used one would cost. There is probably a member here who could sell you one. Try posting in the wanted section.

You still have aluminum traveling around that motor and if it where mine I'd split the cases and go for it, or just look for a whole used motor.

[nisom512]

Being disabled and unemployable, I also try and save on everything I do. I have a small machine shop but still know when to call it quits. You'll spend more on that head than a good used one would cost. There is probably a member here who could sell you one. Try posting in the wanted section.

You still have aluminum traveling around that motor and if it where mine I'd split the cases and go for it, or just look for a whole used motor.

agreed also look on craigs list for a parts bike and maybe the guy could sell you the head for 50 bucks.

I was gunna buy a maxim 650 and it needed a cyclander head so I found a guy with one for 50 bucks and turns out he lived 15 min from my house

Jake

[Roland]

Valve Shims Nearly there.

I appreciate all the helpful advice and I take it all to heart but all I want to do is to try to improve the performance by completing a Tappet Clearance adjustment. Nessissm gave the most likely answer to my original question,

Q) "What would cause the #1 Intake Tappet to be that far out of Specc."
A) "Lower Journal being worn down.

I am not quite ready to give up on this head due to one bad Cam Cap which Nessissm was so kind to provide the replacement. Not just yet anyhow. I have already cleaned up the journals and verified the best I can that the bore is identical or at least close enough that I can't measure an issue. As I stated in the previous post the oil starvation was something in the bikes past. There is no oil starvation at this point. The oil is flowing quite well to all parts of the Cam.

I am not ready to do a complete engine overall not in the middle of riding season anyhow. I have already been off the bike for a solid week and I can't take not riding any longer. I look pretty goofy on my wifes little 250 VStar.

If I were to go through the trouble of replacing the head it would be a waste of time and money unless I did a complete engine overhaul, pistons, valves, valve seats, valve guides, shims, oil seals, etc.. Who knows what I might find or cause to go bad as I get further into it.

There is no promise that the head I would end up with might not have a whole different set of issues. Not to mention the potential for causing issues with the Exhaust mount, Carb Boots, or unexpectedly breaking off bolts(remember she is over 30 years old)

The 78GS750E engine is a beast and is nearly bullet proof. Look at the pictures of the severely worn out Journal Cap and realize I was still able to do 90+MPH without even trying hard. This bike has received a whole lot more TLC from me than it's previous owner and I plan to conitnue to improve it for many years to come. This winter would be a much better time for me to do a complete overhaul.

Today's Results after 2 trips to exchange shims
Valve Shim Gap Result
E-1 2.50 .08-.10 Too Loose Need 2.5x
E-2 2.60 .06-.08 Good
E-3 2.60 .10-.13 Too Loose Need 2.60x not 2.65 &not 2.60
E-4 2.55 .05-.06 Good

I-1 1.75 .35-.38 Too Loose Need 1.95
I-2 2.70x .05-.06 Good
I-3 2.90 .03-.04 Slightly too tight Need 2.85x
I-4 2.70 .06-.08 Good

Before Starting the swap the originally shims were
Exhaust-Original Shim
1------------2.5
2 -----------2.6
3 -----------2.6
4 -----------2.65

Intake-Original Shim
1 ----------2.55x
2 ----------2.70
3 ----------2.80
4 ----------2.70

[zathros]

Winter is the best time to overhaul. Start looking for the parts now and keep looking till you find something good enough and in your price range. You may find a whole motor for the price of a used head. Some people just need to get rid of stuff. You are right, without doing the rest of the motor you could end up with a pile of trash by doing a half a$$ed job. On the other had, if you drop that valve you'll still trash the motor. Just keep in mind that as the cam journal wears further and or the throw of the valve gets loose, the valve retainers will get loose and you could drop a valve. So enjoy riding, but don't get too crazy with the rpm's or you could face a seized engine, something you don't want to happen in a turn, or with someone on back.

You'll know at the end of the season how it's all worked out. Who knows, I drove an MG for years and when I took it apart for the rebuild every ring was broken in at least two places. I only decided to rebuild it because the web between the intake and exhaust valve cracked and burned a hole threw a valve. God only knows how long that car was like that.

[Roland]

Timing Chain Tension Adjuster Stuck

O.K. So I just finished polishing up the lower "C" journal with 500grit followed-1000grit followed by super fine steel wool and it is looking quite nice and is nearly as smooth as the original. After finishing that I pulled out the cam so I could polish it up as well but once I put it back in and got the timing correct the Timing Chain Tension Adjuster is now stuck but the chain and cams move very well but I used to be able to release the chain by holding the tensioner 1/4 turn then releasing.

What would cause this?

I am monitoring this thread while continuing to work on the bike.
Any help would be greatly appreciated.

[chef1366]

You needed to remove the cam chain tensioner in order to remove cams. If you didn't you need to and cock it before reinstalling.

[Roland]

Idler freed up

Never mind apparently the Tension adjuster got jammed when I re-torqued the idler. I loosened up the idler held teh Tension adjuster in it's released mode and re-re-torgued the idler. Now the Auto Tension Adjuster is working as it should.

[Roland]

Idler freed up

Thanks Chef, the cocking is what I forgot the 1st time.

[Roland]

Started up right off the bat

Well it's been 7 days and several hours but my baby is back together and she started with no hesitation.

Now I am off to bed. I will give her a full test tomorrow.