Author Topic: '74 850T rebuild post flood  (Read 2623 times)

Offline Testarossa

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'74 850T rebuild post flood
« on: June 10, 2018, 02:41:08 PM »
I finally have the time to begin my third rebuild of this grande dame.

As some of you know, I put Gilardonis on her about 8 years ago and she was running great. Then we got knocked down by an SUV, at low speed, on the way home from Ouray in 2013 (thanks, Lannis, for the escort home). New front end etc.




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Then in 2015 the Boulder flood, and she drowned.




I did a pretty good rebuild including the gearbox and timing box but didn't pull the crank. 2000 miles later I had wrecked bearings and a broken piston ring. So last year I pulled everything out and sent the crank out to be turned. I now have all new bearings, seals, pistons/cylinders, oil pump etc. We'll see how quickly this comes together -- meanwhile I have three working bikes to ride.

First step is cleaning the cases. For $15 I bought a blasting gun and 20 pounds of baking soda, and for $5 repaired my 5hp 20gal air compressor. Used about 15 pounds of soda at 90psi. Here's the preliminary result -- the engine case looks nice but the sump, timing case cover and gearbox need more scrubbing.







« Last Edit: April 28, 2019, 10:47:54 AM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline canuck750

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Re: '74 850T rebuild post flood
« Reply #1 on: June 11, 2018, 10:54:43 AM »
Try soaking the dirty castings with a good quality mag wheel cleaner followed by a high pressure car wash blast, dry it off and then give it another soda blast, that usually works for me.
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Offline wirespokes

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Re: '74 850T rebuild post flood
« Reply #2 on: April 27, 2019, 08:33:05 AM »
How about an update?

Poor baby's been through a lot! Hope she's all back together now and on the road?

What's it look like now?

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #3 on: April 27, 2019, 02:30:23 PM »
Good timing. Friday was my last day skiing so I got up early this morning and pulled out all the bits and pieces I've collected for the T. Washed the crankcase and blew out the oil passages to make sure all the baking soda was gone. Plan is to get the crank and cam in this weekend.

First, I found this scoring from the timing chain. I'd forgotten about this, left over from the original rubber block tensioner. The Valtek tensioner fixed the problem.




I bought a new oil pump. When I unwrapped the thing it only turned about a third of a revolution and bound up. So I took it apart, turned the gears against one another, reassembled and turned again, filled it with 20/50 and turned it again until it rotated freely, then took it apart and cleaned it thoroughly to get rid of any steel and aluminum bits that might have come adrift in the 'break-in' process. You can see in the picture how sharp edges from machining the steel gears might bind.




Pete Roper's excellent instructions on big block reassembly of course focus on an oil-filter model, and my T is pre-filter. It has this oil pick-up assembly obtruding into the sump, and it will get in the way of installing the rods. Because it's held in place by the oil pump mounting bolts coming through the front wall of the case, I'll put off installing pipe and pump until after the rods are torqued up. BTW I haven't found any mention of this order-of-assembly issue in any of the downloadable manuals on Bender's site.




That's it. Running out for a tube of red Loctite and will button up the front main bearing and camshaft assembly tonight.

Oh, and I haven't been able to get the Woodruff key out of the old oil pump drive shaft. I'm guessing some judiciously applied heat might drop it out, and then I'll have to freeze the key and maybe heat the new shaft to get the key in.

I put the new front bearing (with the oil-feed dowel) in the freezer for a couple of hours and it dropped right into the case. Torqued the bolts to 22 ft-lb. Couldn't find a torque value for the three cam keeper nuts so I used 10 ft-lb. All Loctited.

Later: This is it for today.







« Last Edit: April 27, 2019, 07:12:20 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline wirespokes

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Re: '74 850T rebuild post flood
« Reply #4 on: May 01, 2019, 10:12:03 AM »
Glad she's going back together.

Since it's all apart like this, was there any thought of modifying to accept a filter?

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #5 on: May 01, 2019, 12:01:11 PM »
Quote
was there any thought of modifying to accept a filter?

I did think about it. I don't have the tools to do the necessary drilling in the case, but there are plenty of good used cases around. Filter-type sumps are rare because (as Charley explained to me) people neglect to unscrew the center bolts and damage then try to pry them off, which of course damages them. That left the Outsider solution, which seems like a lot of money. Considering that this bike went 50,000 miles on 2,000-mile oil changes without significant wear (before the flood), I finally decided just to go back to stock. I opened the sump to inspect at 35,000 and 43,000 miles (when the Gilardonis went on) and everything was tight and clean -- even the pickup screen was clean.
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #6 on: May 02, 2019, 06:41:00 PM »
Gail has a dozen projects going and I'm the muscle, so I get to the T sporadically. Today I found an hour and got the freshly turned crank in, then torqued in the rear main bearing. I don't have the seal-installer tool so I steamed the bearing flange, froze the seal and tapped it in.






Next step is to weigh the new piston bits, match them to the rods and get them installed.


70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #7 on: May 19, 2019, 06:52:58 PM »
Have been loafing along, building planter beds for Gail and fussing with the new-to-me XR350R. But after ordering the wrong crankpin bearings I got everything copacetic and torqued in the conrods.



« Last Edit: May 19, 2019, 06:55:26 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline SED

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Re: '74 850T rebuild post flood
« Reply #8 on: May 20, 2019, 10:18:58 PM »
Lookin' good.  Like those beam type torque wrenches.
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Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #9 on: May 27, 2019, 04:15:20 PM »
I was just about to install the new oil pump and button up the sump when Joe Walano offered to sell a oil-filter conversion kit, ostensibly for early Tontis with no machining needed. Made by Moto MS, a Guzzi/Ducati shop near Bregenz in Austria. Has anyone installed one of these?
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline NCAmother

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Re: '74 850T rebuild post flood
« Reply #10 on: May 28, 2019, 10:45:52 PM »
I was just about to install the new oil pump and button up the sump when Joe Walano offered to sell a oil-filter conversion kit, ostensibly for early Tontis with no machining needed. Made by Moto MS, a Guzzi/Ducati shop near Bregenz in Austria. Has anyone installed one of these?
Can you post a picture, I also have an oil pan with external filter but I've not seen one like it before..

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #11 on: May 28, 2019, 11:47:09 PM »
This one puts the filter inside the pan. The company is apparently defunct. I was looking for feedback from someone who has installed this.

Photo here:

https://www.facebook.com/groups/898627433562137/permalink/2246065095485024/?sale_post_id=2246065095485024&ref=messenger_banner
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Antietam Classic Cycle

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Re: '74 850T rebuild post flood
« Reply #12 on: May 29, 2019, 04:04:43 PM »
Charlie
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Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #13 on: May 31, 2019, 03:58:42 PM »
I decided just to go filter-less, as Lino intended. Installed the new pump only to find that the old pump was a loop-frame item with the half-moon woodruff key, and the new pump needs the newer rectangular key. So no timing chest work until the new key arrives. Will work on the gearbox instead. All that needs is a fresh selector spring, just to be safe.



« Last Edit: May 31, 2019, 03:59:33 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #14 on: June 05, 2019, 04:48:12 PM »
The new oil pump shaft is machined for the new-style rectangular Woodruff key, whereas the old one had a crescent key. The new key arrived today. It wasn't a drop-in fit because the keyway in the sprocket is narrower than the key. After a little filing and fiddling, it came together so I finally got the timing chain in. Here it is, ready for the rattle gun.




Here we are, case closed. The thing now weighs 60 lb, and with the flywheel and clutch will weigh about 80 lb. That's too much for me to lift easily so the next step is to make a wooden cradle on the shop lift to hold the engine while flywheel/clutch, gearbox and frame are bolted on.





While waiting for the key I opened up the gearbox so as to replace the shifter spring and oil seals. All parts in hand so it ought to go quickly now.
« Last Edit: June 06, 2019, 03:42:16 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #15 on: June 08, 2019, 08:20:21 PM »
Reassembled the clutch using my homemade alignment tool. It slips over the clutch hub (which is off the gearbox) and lets me align the intermediate plate by hand.




All torqued down. The torque specs are nowhere to be found in the published tables but the old-timers on this board have values if you search for them:  30 ft/lb for the six bolts into the crankshaft, 22 ft/lb for the eight bolts in the starter ring.


« Last Edit: June 10, 2019, 06:18:59 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #16 on: June 09, 2019, 04:47:39 PM »
Got the gearbox back together. The motivation for opening it was simply to replace the shifter spring:




But while it was open I replaced the seals and o-rings, and looked for busted teeth and worn dogs and forks. No problems. Back together:




Buttoned up, it shifts into all five gears. A bit notchy without oil in the case, but will smooth out as soon as everything gets wet.




Finally --
What are these?  Found them inside the case after it sat idle a couple of years. They feel sort of rubbery. Congealed oil? Gremlin eggs?




There will be a pause. I've been persuaded to swap out the Surflex clutch for SD-Tec (Stein Dinse) plates, and will install new clutch springs too.
« Last Edit: June 12, 2019, 02:26:36 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #17 on: June 16, 2019, 07:04:27 PM »
Another learning opportunity. Installed the Stein Dinse clutch and while I had the gearbox off I opened it again to double-check that I'd gotten the shims right, because I thought there were too many false neutrals in there. As it turned out I took 1.5mm of shims off the main shaft to get the length to 145mm and the shifting improved. Now I find that the speedo drive ball I bought from one of our favorite suppliers is 4.5mm instead of the regulation 2mm and of course it won't fit in the spline, so another day or two before I finally attach the frame.

Yes, I'm doing everything twice on this build, sometimes three times. I'm getting pretty good at reassembling the gearbox though.
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Antietam Classic Cycle

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Re: '74 850T rebuild post flood
« Reply #18 on: June 17, 2019, 10:25:41 AM »
Now I find that the speedo drive ball I bought from one of our favorite suppliers is 4.5mm instead of the regulation 2mm and of course it won't fit in the spline, so another day or two before I finally attach the frame.

The original is 4 mm. When I need one ball, I usually just harvest it from a cheap, suitable, ball bearing.
Charlie
http://www.AntietamClassicCycle.com
'69 V700
'69 Ambassador
'76 Convert
'85 Moto Morini 350 K2

Most used word in my vocabulary lately: "whatever", usually delivered with all of the disdain of an aging Valley Girl...

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #19 on: June 17, 2019, 12:11:29 PM »
Quote
The original is 4 mm. When I need one ball, I usually just harvest it from a cheap, suitable, ball bearing.

Yup, 2mm way too small. That was in the vendor's catalog and they've fixed it and proper ball en route. No hope finding a 4mm ball within an hour's drive. Bad ball miked at 4.7mm.
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #20 on: June 22, 2019, 01:41:21 PM »
Everything buttoned up again. Another minor glitch: with the clutch pushrod in place, the outer body stuck out of the case by about 10mm. Obviously wrong. Couldn't be new clutch springs or thicker plates, because those issues would have the opposite effect, and I don't think it's possible to put the pressure plate hub in upside down. Eventually I popped the gearbox back off the engine and used the pushrod to clear out the original cylindrical rod seal that was stuck inside the shaft. It's 12mm long. Everything back together, the outer body rides 2mm below the edge of the case. Tested the clutch (photo) and it works perfectly.




Dizzy first because it's easier to wrench without the right cylinder in the way.




photo gallery online

Now, Gilardonis and heads, oily box, then clean up the frame and drop it on.
« Last Edit: June 24, 2019, 04:05:09 PM by Testarossa »
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #21 on: June 25, 2019, 02:35:57 PM »
Real progress now. Frame on, cylinders and heads.  'Lectrics next.



70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

Offline Testarossa

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Re: '74 850T rebuild post flood
« Reply #22 on: July 14, 2019, 08:59:36 PM »
Slow but steady progress. Valve lash set, fork on and ready for front wheel and brake, rebuilt cardan mounted in new carrier bearing so the swingarm goes in next. Conceivably we could be running by the end of the week, maybe. I had hoped to be done for the BMW rally next weekend but probably not -- too much nonmoto stuff going on here.
70 Triumph TR6R, 74 850T, 74 Yamaha TA125, 83 XR350R, 89 Mille GT, 99 F650,
Gone: 59 Piper Comanche 250, 69 Harley/Aermacchi 350SS, 71 Honda CB500/4, 74 Laverda 750 SF2, 91 Suzuki VX800, 50cc two-stroke scoot

 

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