Top End Rebuild

xsjohn · Posted: January 16, 2009, 8:52 pm Post subject: Re: Top End Rebuild

The last good factory seal I replaced ended up leaking....if that helps ....

xsjohn

Retiredgentleman · Posted: February 1, 2009, 7:50 pm Post subject: Re: Top End Rebuild

Update on my engine work. I decided it was better to remove the shifter shaft in order to replace the shifter shaft oil seal. So, clutch removed, shaft removed and new oil seal replaced.

While the clutch was removed, I thought I may as well inspect for wear. Plates and springs all in good shape, with minimal wear. I was glad to see that I have a washer on both sides of the thrust bearing, which agrees with the revised Yamaha clutch drawing.

That was all good news, but I did find one problem area. The PO seems to have misplaced a washer. The very first washer from the crankcase side is missing. There should be a small diameter 1 mm washer and then a larger 2 mm washer. The small one is gone. This missing washer moves everything closer to the crankcase. This resulted in the clutch basket gear rubbing on the crankcase, and the back of the clutch basket wore a small groove due to contact with the primary drive washer. My clutch has been working fine for me, but I would like to have the correct parts in place.

So, if anyone has a washer of the following size, please let me know.
ID= 0.990" OD= 1.376" Thickness= 0.039" ( 1 mm)

Retiredgentleman · Posted: April 9, 2009, 11:42 pm Post subject: Re: Top End Rebuild

Finally got the engine back together and back in the frame. Engine started up fine and took the bike out for a short spin around the neighbourhood. I've not yet installed the top engine stay, as I need to put some kms on, and then re-check torque on the head studs.

Pamco ignition seems to be working OK. Using an Accel supercoil that I had previously used with points ignition.

New rings, new valve seals, valves lapped, new camchain, new front guide, long pushrod to replace 2 shorties. May take a while to seat the new rings.

Clutch was opened up for inspection, and all plates and springs were in spec. One washer was missing ( curse those PO's), which I ordered from Yamaha.

New VR-115 solid state voltage regulator, replaced the original mechanical relay type. Its controlling voltage nicely at around 14 to 14.4 volts. I also removed the original rectifier and installed 2 bridge rectfiers using 6 of the 8 diodes. Thanks to Pamcopete and his threads over at 650garage that showed us how easy these mods are.

I'm happy to see there are no oil leaks from the engine, yet Smile

I'm hoping this rebuild has cured my high oil consumption. The PO had not re-torqued the engine studs and oil was being sucked from the camchain tunnel.

All in all, the re-build was more work than I thought it would be, but it sure felt great to take that first ride. Cool

pumps · Posted: April 10, 2009, 1:07 am Post subject: Re: Top End Rebuild

I'm glad you're on the road again. You have taken all these great pictures of the parts for us to see and helped me to learn a thing or two.

xsleo · Posted: April 10, 2009, 1:44 am Post subject: Re: Top End Rebuild

I'm about at the same place with my bike.Starts and runs good, no smoke. I had trouble with chargeing, now charges, big problem was my meter not working right. Now I need to put the left side cover on, set the clutch. And try riding it. Maybe tommorrow.

yamaman · Posted: April 10, 2009, 7:25 am Post subject: Re: Top End Rebuild

Congratulations RG, top work!

Skip · Posted: April 10, 2009, 10:04 am Post subject: Re: Top End Rebuild

RG
Glad to hear you got the old girl fired up!You will find a nice difference with the 1 peice push rod.I changed mine last year and would highly recomend it as a cheap upgrade!I will be watching your break in progress and engine performance closely as I feel I had the same problem with my 78 of oil consumption at the cam chain tunnel.I got my parts back from the machine shop.1st oversize re-bore,and new valve job with valves and guides checking in OK as well as being assured the surfaces were not warped,so I feel my oil consumption was in the cam chain tunnel area like yours.What did you use for torque on the big 8 head bolts? that seems to be a topic of debate! Your attention to detail is second to none RG, thanks for sharing!

Retiredgentleman · Posted: April 10, 2009, 1:30 pm Post subject: Re: Top End Rebuild

xsleo;
Yeah those cheap digital meters go erratic around a running engine. Perhaps RF interference generated from the ignition and poor shielding in the cheap meters. I paid $6.00 for my cheap digital just as a curiousity, but think I'll toss it in the garbage. Still using my Micronta (Radio Shack) analog meter I bought 39 years ago (quality meter, made in Japan). Guess I got my monies worth on that meter Smile

Good luck on getting the bike out on the road.

Skip;
I don't think we can overstate the importance of proper torquing of the head bolts. Looks to me that this has caused alot of grief. 5twins had given me some good tips, such as using lacquer thinner for final cleaning prior to using 3-bond 1104 for metal to metal joints. I used 3-bond 1104 around the camchain tunnel and the 4 outer studs that are exposed to oil (Head Gasket). Using 30 ft-lbs on the 8 large 10 mm studs. Using 14 ft-lbs on the 8 mm top bolts and under spark plugs.
Using 7 ft-lbs on the 6 mm bolt at back/centre area. I also put a little oil on the threads to help get correct torque numbers. Make sure the dowels are clean and fit fully down into their recesses.

Leave the head stay off, while you put on some kms...........then re-check torque numbers.

Nice weather coming, so get that engine together!

xsleo · Posted: April 10, 2009, 6:32 pm Post subject: Re: Top End Rebuild

It isn't a real cheapy. I think I paid aroud $25 to $30 for it 5 to 10 years back. Been long enough I'm not sure how much or when. It's a Sunpro CP7674 by Actron. I plan on getting a good analog meter. I did ride it about 15 miles today , needs a little carb tuning, but ran good. A few pops and sputters.

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