Engine on the bench, planning a check and rebuild


Information and questions on GL1000 Goldwings (1975-1979)
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Saltspringer
Posts: 36
Joined: Fri Oct 19, 2018 3:33 pm
Location: Canada
Motorcycle: 1976 GL1000 in Antares Red

Engine on the bench, planning a check and rebuild

Post by Saltspringer » Sun Jan 05, 2020 7:35 pm



I have a question regarding an upcoming engine overhaul....

I recently cosmetically restored a 1976 GL1000. It's been a fun bike to ride, but the exact mileage is unknown, it has some primary chain rattle at idle and blows a little smoke. Since the mileage isunknown I can only assume that its probably high(ish) or the engine has not been cared for to well.

I planned a rebuild however recently I picked up for free, a partly stripped GL1000 with 17,000 miles on it. It was just one day away from being crushed, but cosmetically it was in good shape. Most body parts have gone, but the original exhaust is in great shape and I believe the mileage is genuine.

I have pulled the heads and they look fine, cams are in good shape, valves look good but I will check and lap, the bores are smooth and score-free. No damage to the piston crowns, only a modest amount of carbon on the LHS set. Using this engine as a donor I am planning to go through it and complete any mods, upgrades and checks while its sitting on my work bench. I have done a bit of reading and come up with the following items:

Change cam belts.
Change cam tensioners.
Check and lap valves.
Replace valve seals.
Upgrade to a Dyna ignition.
Removing the B plate from the clutch.
Check the water pump and replace the impeller with a metal one.
Test and if necessary replace the thermostat.
Service the starter clutch and chain, replace or renew if required.
Check condition of stator wiring (I would like to check the stator health, is there an easy way of doing this?)
Switching out the slipper primary tensioner to the later spring type.

With the experience here on the list, is there any other items that I should look at, swap out, renew, or check?

Many thanks for all and any advice.


1976 Honda GL1000, resurrected....

1946 Norton Model 18, 500cc single
1946 Harley WL45 Flathead
1960 BMW R60/2
1972 BMW R60/5
1973 BMW R75/5
1973 Norton Commando
1981 Moto Morini 500
1960 Triumph TR3A sports car, in many boxes.....

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DenverWinger
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1977 GL1000 (2002-2006) sold

Re: Engine on the bench, planning a check and rebuild

Post by DenverWinger » Sun Jan 05, 2020 10:16 pm

You can do a voltage test on the stator with engine out of the bike. Normally would expect to see 50-70v AC between all three stator legs at 3000 RPM, but you should still see some sort of low voltage AC power out of the stator at cranking RPM.

With the sparkplugs out or the heads still removed and engine on the bench you should be able to put a set of jumper cables to the starter motor, touch the negative clamp to the engine block to run the starter, don't make the last connection at the battery (keeps any sparks away from the battery). It should crank pretty fast with heads off.

Beware if the heads are off and there's still oil in the sump (not necessary to have oil in engine for this test) it's going to want to pump oil to the missing heads while cranking and you'll wind up with an oily mess on the bench, put some grubby rags under the cylinders to catch any oil.

What you are looking for is roughly the same AC voltage reading between all three of the stator legs while cranking the starter. Also measure ohms between a stator leg and ground, should be no reading (open circuit). If stator passes these tests it should be fine. Also you can visually inspect the shellac insulation on the stator windings if you are opening the back cover to service the starter sprague clutch. Dark shellac is OK, but not crispy-burnt looking.
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
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AZgl1800
Posts: 2001
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Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Engine on the bench, planning a check and rebuild

Post by AZgl1800 » Mon Jan 06, 2020 10:21 am

I don't see a need to lap the valves or hone the bores.

it just needs to be run in again
~John
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Saltspringer
Posts: 36
Joined: Fri Oct 19, 2018 3:33 pm
Location: Canada
Motorcycle: 1976 GL1000 in Antares Red

Re: Engine on the bench, planning a check and rebuild

Post by Saltspringer » Tue Jan 07, 2020 8:18 pm

I was planning to just dust the valves and seats to make sure all is well. Looking at the bores I don't believe they need any work. I had a couple of extra offline suggestions and will post a list in a few days. Might be useful to anyone else contemplating a similar project.

Andy


1976 Honda GL1000, resurrected....

1946 Norton Model 18, 500cc single
1946 Harley WL45 Flathead
1960 BMW R60/2
1972 BMW R60/5
1973 BMW R75/5
1973 Norton Commando
1981 Moto Morini 500
1960 Triumph TR3A sports car, in many boxes.....

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