Top End Noob

So I installed the camshafts, idler and tensioner and set the timing. When I hand turned the engine to confirm the settings, I found some slack in the chain that jumped a tooth. No problem, just had to redo all the timing stuff.

*side question - Do you have to install the idler before turning the engine? Can you turn it a few times to check things and then install that piece? I installed it both times before hand cranking because Clymer sets it out in that sequence, but it would be nice to postpone that part of the process to save a step and facilitate double checking the pin count between #2 and #3.

Anyway, the second effort came in nice and tight. Checked and adjusted valve clearances. A couple of them were tight, a couple were pretty loose, but it looks like the valves are closing well (they did not seep any acetone when tested).

Did a compression test. The results were much better, but still a little wonky. A cold test came up with 90/90/65/90. The 90s don't trouble me, since I expect those to come up once the new rings break in. The off-kilter compression in No. 3 is troubling. Those valves and rings should be tight. That is the cylinder that had the bad spark plug hole and previously botched insert (one of the f**kups that wasn't mine). I retapped and installed a new insert there. I know that inserts are bad, etc. But the insert is the only candidate I can think of as the source of bad compression. The compression tester is pretty hard to insert into that deep plug hole with mildly sketchy threading. In fact, before the tear down, the bad plug hole prevented any compression testing. So I may not be getting an ideal connection with the tester, and/or the insert may not be sealing well. I have a replacement head coming anyway. If I cannot sort out the compression issue, I may just swap out the heads later, provided that the various threads on the second head are legit.

Next, I ghetto timed the ignition (using the grounded exposed spark plug to time the spark). I cannot seem to find a good connection for my static light.

Installed the carbs -- which have been completely rebuilt, dipped, re-jetted, exorcised of demons, etc. Set the fuel screws 1 turn out and the air screws 1.5 turns out to start.

Ran some petrol into it. Checked for float bowl leaks, so far so good.

Hit the starter. Turned over, but didn't catch. Curses.

Installed the spark plugs . Heh.

Grabbed a fire extinguisher, just in case.

Turned on choke.

Turned key.

Pushed starter button.

She fired right up like a dream. WOOT!!

Of course, there are still more tasks on my list before riding this beast. I need to vacuum synch the carbs and fine tune the fuel and air mixture. Before I get to that, however, I have a couple of snags.

1. Tachometer. I reconnected the tachometer when I installed the head, but I botched it somehow. Specifically, I get no tach readings on the dial. I must not have properly connected the cable to the worm gear. Because the pipes were hot from idling, I left it until tonight. Hopefully, it's just a simple connection issue, since I need a tach to set the carbs, idle, etc.

2. Smoke. I only ran the engine for 2 -3 very short periods, less than a minute each time. After 10-15 seconds, there was some light wispy smoke coming off the head and the header pipes. I killed the engine each time it appeared. My best guess is that various drips, drabs and my greasy paw prints are burning off as the engine warms. There is nice light smoke (not black or white, etc.) coming from the tailpipe, so I don't think the pipes are clogged. The head smoke did not seem to come from any particular source like a bad pipe connection. The gasket seams also don't show any drips or leaks so far. Tonight, I will wipe down and clean off all the surfaces to eliminate any grime that might be burning off. Hopefully that is all there is to it.

Big shout out to Nessism who came through like a champ with a replacement bearing cap bolt! All should worship the ground he walks on.

Over the weekend, I double-checked one of the valve assemblies to make sure it was seating well, reinstalled the cylinder head, tapped out the exhaust bolt holes and got the exhaust back on there. I might need to do a hair more tapping on one of the bolt holes, but I think the pipes are solidly on there. Not trying to tempt fate on another bolt fiasco.

With my shiny new bolt, I can finally time the chain, install the camshafts, install the tensioner, and check the new valve clearances. God willing, I may get to test compression and even start the damn thing.

Hurm, I didn't consider the filter issue. Perhaps this is too clever by half.

Oh well.

Don't see why you couldn't. You won't have to worry about holding the throttle open You'll also be drawing in un-filtered air, but just for a quick compression test that should be NBD.

Bumping for question about compression test. Can I do that with the carbs off the bike?

Never could get that drill to center.

But with two dimples in the bolt piece, I could grip the middle with some needle-nose pliers and twist that bastard out. WOOT!!

I gingerly twisted another bolt in there to check the threads. I think they are good, though the top thread got a little ravaged.

Now I just need another bolt.

Stay tuned for the next f**k up in this saga.

[Nessism]

Yes, grab the dowel pin and pull it out. Hopefully you will have enough sticking up to turn using a punch and hammer.

A good set of pliers will take out the locate dowel or pin. Pull, turn wiggle and it should come out

I looked over other threads about bolt extraction. Things look bleak.

Consider this fiche:



The left-hand circle is where the bolt snapped. It is one of the pinned holes, and the pins shown in the right-hand circle.

The broken end is most of the threaded part of the bolt, maybe 3/8 - 1/2".

It is not level at the break, so centering a bit is . . . difficult. Tried the smallest bit/shift to center approach, but it's hard to see how that is working because the bit tends to dance about. It also is slow going into that hardened steel bolt.

The dancing may have tagged the exposed aluminum threads as well.

I cannot get a Dremel grinder in there to level off the break, because of that pin.

I fear using any heat on this will be a disaster, since there are three different metals (aluminum head, steel pin, and hardened steel bolt tip) to navigate.

Is there any way to remove that pin? I might have better luck and visibility if I did not have to work though that extra tunnel.

That bolt nub is hateful. I laughs at my drill bits. Left it soaking in penetrating oil until I take another stab at it tonight.

Will continue to work at it while I wait for that other head to arrive. Given my luck, the bolt will come out on the same day that the other head gets here.

Some small consolation in that the replacement head was not terribly expensive. With any any luck (heh), I'll break even on the spare valves, shims, etc. between the two heads.

[Nessism]

You need to slow down. Worst case is take the head back off again and drill out the bolt. Use a small drill bit first and try to hit center. Work the bit sideways to center up the hole and then step up the drill bit size. If you use LH bits the screw nub will spin out at some point during the process. I've done two of those exact bolts before and it took some time but was easily doable.

Your luck continues.

I have spare bolts it you need. Drop me PM with your address as necessary.

Thanks, but there is no getting that broken one out of there. It's in the pegged corner, so it's too deep to try and cut a slot for flat head. Cannot get a pilot into it for a lefty bit, not even with a titanium bit.

I already ordered a used head from eBay that I was looking at before. It might get here in 2 weeks.

Might even ride the bike by Christmas.

[Nessism]

Your luck continues.

I have spare bolts it you need. Drop me PM with your address as necessary.

Edit: don't start drilling until you try to turn the bolt out with a small punch - try to knock it on a tangent so it turns. Many times broken bolts like that spin right out.

Set the timing perfectly.

Tightened down the bearing caps evenly. Then went to torque them down to 8 ft/lbs per Clymer.

Snapped a bearing cap bolt. Went immediately from easy turn to pop. Never got close to 8 ft/lb on the torque wrench.

Of course, those bolts are made of specially hardened steel, so nothing drills into the hole to extract that bolt.

Hurray!

Quick question on the compression test.

Instead of doing it with the throttle wide open, can you run the test before installing the carbs, and leaving the intake boots open instead?

Figured it might save the step of installing the carbs, since I will just pull them back off if the compression numbers come back crappy.