The 70's called and I answered. 1975 GL1000 project

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old_smokey
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Re: The 70's called and I answered. 1975 GL1000 project

Post #31 by old_smokey » Mon Sep 09, 2019 12:25 pm

Been on a few rides now and really getting a feel for the bike. I really like this engine. I took my wife on a ride as well and it handled 2-up without a second though. She had a big smile the whole time.

One thing that wasn't up to snuff was the suspension. The rear shocks must have lost dampening years ago, so I'll find something suitable to replace them. I like Ikon shocks on these old Hondas.

For the front, I need new fork tubes. Oil is pouring past the seals due to some chrome pitting. The oil is dripping off the fork lowers close to the brakes. Not good!

Can anyone tell me if the 1975 GL1000 uses the same fork inner tubes as the 76-77, or even up to 1979? I know the lowers are different do to the brake caliper mounts and spoke vs comstar wheels. But what about the inner/upper tubes, were they the same? Partzilla parts fiche shows three part numbers for the tubes. Some say only 1975, some say 1975-1979... I want to order a new set this week and get the bike a bit safer.
1975 GL1000
1974 CB350F
1974 CB750K
1978 CB750K
1977 XT500D
1982 XL125S
1985 R80
2001 XR650L

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ericheath
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Re: The 70's called and I answered. 1975 GL1000 project

Post #32 by ericheath » Tue Sep 10, 2019 6:37 am

For the weight of the bike, most feel the forks are under sized. Upgrading springs will help but they’re still 37mm shocks. I swapped 41 mm Magna forks in and going back onto a stock bike makes the forks feel like jello in comparison.

1100 (39mm) or 1200 (41mm) front ends swap if you swap triple tree and down. Several have used a 1200 triple tree and swapped newer sport bike front ends.

This takes away from period correctness. Speedometer has to be addressed.

I believe the 75-77 forks were the same. Maybe all year tubes. I cannot say for sure though.

Roger, Rcmatt007 posted several years ago:

“front end interchangability on 1000's: fork lowers, rotors, wheels, brake calipers, speedo, brake light sending switch

75-77: all interchange

78-79 all interchange

75-77 will not go on 78-79 without changing everything

actual brake cylinders will interchange”
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi

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robin1731
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Re: The 70's called and I answered. 1975 GL1000 project

Post #33 by robin1731 » Tue Sep 10, 2019 2:09 pm

ericheath wrote:snip............
actual brake cylinders will interchange”


Brake cylinders? Is that master cylinders? Brake calipers? Tell us what you mean Rodger. ;)

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder

old_smokey
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Re: The 70's called and I answered. 1975 GL1000 project

Post #34 by old_smokey » Thu Sep 12, 2019 11:00 am

Yeah I'm not quite clear on what that list means either! I know the fork tubes are the same diameter, I just don't know about length. I'll do some more hunting around.

In the mean time, I'll share some more progress on my timing debacle.

I got the Dyna S unit in the mail yesterday morning. I couldn't wait to get home and install it. Love getting new parts in the mail.

When I pulled the points and advance unit out, I noticed several unfortunate things..

1 - The locating pin between the cam and the advance unit was sticking out at a really weird angle. Rather that point straight out, it was sticking out at an angle. Further examination shows the hole had been ovalized. It looks like something tried to rip the pin out of the cam, and damaged the hole in the process. The pin itself seems ok.

2 - on the back of the advance, where the pin slots in, there is more damage. The slot has a heavy dimple in it, and is actually cracked! Further evidence the cam tried to spin but the advance mechanism resisted, pushing back against the locating pin.

3 - The points backing plate is bent away from the cam. Ah ha, this confirms my initial hypothesis from last week, when I found some non-factory screws had been used to secure the points to the backing plate. These screws stuck out way beyond the back of the backing plate, and would have gotten tangled in the advance.

So, my theory is the previous owner used these long screws. Then tried to fire up the bike, and the advance attempted to rotate, caught on the screws, which sheared off after wreaking havoc. The points plate was pushed out and away as the advance attempted to free itself and spin with the cam.

Two things which I can't explain - usually you'd rotate the engine by hand when setting the static timing, at which point you'd discover the error of longer bolts. Maybe he just never did this? And second, the front side of the advance unit doesn't appear to have any noticeable damage. Maybe I just missed it, but this seems odd to me.

I did find bits of shredded metal in the ignition housing though, and scarring along the circular inner walls of the housing, as if something was dragged around.

Anyway, I was bummed mainly about the damaged hole in the end of the cam. Nothing else really matters much. I have a spare advance. But the oval hole could be an issue. The Advance is able to move several degrees back and forth before you tighten down the nut, which could explain why my points plate had to rotate so far clockwise to get lined up.

I don't know if it's practical to repair the hole, vs replace the entire head and valve train with a complete donor head, given I also have a stuck exhaust stud and cracked casting next to it. Maybe I just bin the entire head and bolt on a good used one.

I also noticed the cam 'nose' wobbles quite a bit. Maybe close to 1mm wobble. I know there is typically some wobble, but this seems very extreme to me.... any input on that?


So I slapped the Dyna S on doing the best I could with the condition of my parts. And don't you know it runs like a dream anyway. Started much better, much crisper throttle. I was able to static time both pickups perfectly without much tweaking. All I had to do was use a smaller washer on one of the bolts which interfered a bit with a pickup. I also had to remove the plastic P-clip holding the wiring to the backing plate as it forced the wires against the spinning rotor.
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1975 GL1000
1974 CB350F
1974 CB750K
1978 CB750K
1977 XT500D
1982 XL125S
1985 R80
2001 XR650L

old_smokey
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Re: The 70's called and I answered. 1975 GL1000 project

Post #35 by old_smokey » Thu Sep 12, 2019 11:02 am

Here's how it sounded right after starting up with the Dyna S.

It ran with full choke for about 5 seconds before I hit 'record'.

1975 GL1000
1974 CB350F
1974 CB750K
1978 CB750K
1977 XT500D
1982 XL125S
1985 R80
2001 XR650L

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robin1731
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Re: The 70's called and I answered. 1975 GL1000 project

Post #36 by robin1731 » Thu Sep 12, 2019 9:50 pm

No need to change the whole head. Just find another came from the same year.

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder

old_smokey
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Location: Manitoba

Re: The 70's called and I answered. 1975 GL1000 project

Post #37 by old_smokey » Fri Sep 13, 2019 10:49 am

I'd like to keep the head/rockers/cam paired if I can. If I'm going to put in a used cam, I want the corresponding rockers.

Found this '77 complete head for $20. Looks clean. Waiting to hear back on the rocker surfaces and cam lobes. If it's good, I'll pick this up. 75-77 heads and cams are all the same, right?

https://www.ebay.ca/itm/Honda-1977-GL10 ... fresh=true
1975 GL1000
1974 CB350F
1974 CB750K
1978 CB750K
1977 XT500D
1982 XL125S
1985 R80
2001 XR650L

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pidjones
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Re: The 70's called and I answered. 1975 GL1000 project

Post #38 by pidjones » Fri Sep 13, 2019 11:44 am

"Love 'em all.... let God sort 'em out!"
2006 GL1800 - the Black Pearl
1979 GL1000 project - to be restored
1978 GL1000 with '75 engine - the Hunley
Ex '79 CB750F rat bike - the Rocket - SOLD!
Ex '86 SEi
Ex '77 GL1000
Ex '75 RD400
Ex '72 Penton 125 set up for flat track
Ex '73 RD250
Ex '68 TR6C - chopped

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robin1731
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Re: The 70's called and I answered. 1975 GL1000 project

Post #39 by robin1731 » Fri Sep 13, 2019 10:33 pm

old_smokey wrote:I'd like to keep the head/rockers/cam paired if I can. If I'm going to put in a used cam, I want the corresponding rockers.

Found this '77 complete head for $20. Looks clean. Waiting to hear back on the rocker surfaces and cam lobes. If it's good, I'll pick this up. 75-77 heads and cams are all the same, right?

https://www.ebay.ca/itm/Honda-1977-GL10 ... fresh=true


If you can get a complete head for $20.00 buy it. ;)

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder

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ericheath
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Re: The 70's called and I answered. 1975 GL1000 project

Post #40 by ericheath » Sat Sep 14, 2019 11:22 pm

Has the air jet fix from Randakk been done on the carbs yet? It will help the bog off idle.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi

old_smokey
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Location: Manitoba

Re: The 70's called and I answered. 1975 GL1000 project

Post #41 by old_smokey » Sun Sep 15, 2019 6:26 pm

tried to buy that head... but after the seller said he couldn't actually find it in his parts bin, and it was cancelled. What a bummer. And lame! So I'm back to looking around.

What is the air jet fix?
1975 GL1000
1974 CB350F
1974 CB750K
1978 CB750K
1977 XT500D
1982 XL125S
1985 R80
2001 XR650L

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ericheath
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Re: The 70's called and I answered. 1975 GL1000 project

Post #42 by ericheath » Sun Sep 15, 2019 8:48 pm

http://www.randakksblog.com/how-to-cure ... flat-spot/

Explains it better than I could and includes the variations year-by-year.
Whatever I suggest here should be given ample time for a moderator to delicately correct. I apologize in advance.
77 WING, 1200 engine with 77 heads, cams, gl1100 foot pegs, Magna V65 front end, 764A carbs, [-gone Suzuki M109 monoshock--, replaced with gl1100 shocks] gl 1200 swing arm, gl1500 final drive, wheel and rear brakes Valkyrie seat, Meanstreak tank, Sportster pipes, Power Arc ignition off crank.
77 Wing. black
83 Wing, in pieces
"Continuing education is important even if the subject matter is fairly useless (as in this case)."---Greg Foresi


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