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

[old_smokey]

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.

[ericheath]

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”

[robin1731]

snip............
actual brake cylinders will interchange”

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

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[old_smokey]

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 is maybe ovalized. It looks like something tried to rip the pin out of the cam, and possibly 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 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.

[old_smokey]

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'.

[robin1731]

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

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[old_smokey]

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

[pidjones]

The cams have the same part numbers in '75 and '77.
https://parts.southernhonda.com/a/Honda ... 71004.html
https://parts.southernhonda.com/a/Honda ... 71004.html

[robin1731]

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.

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[ericheath]

Has the air jet fix from Randakk been done on the carbs yet? It will help the bog off idle.

[old_smokey]

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?

[ericheath]

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

Explains it better than I could and includes the variations year-by-year.

[old_smokey]

Hello Wingers. It's been a while as I've been mostly hibernating during this brutal cold winter. -40C yesterday! But the end is in sight, and that means time to get the Wing in shape.

Next up, GAUGES.

My Fuel and coolant temp gauges don't work. I've been reading all about the 7V regulator, but here's the rub - mine is testing fine. 12V in, 7V out, 0V ground.

I tested the voltage right at the gauge as well - 7V. I grounded the wire that runs down to the temp sensor, which should push the temp gauge to HOT, but it doesn't move at all. Haven't tried the same with the fuel sensor yet. So what gives? Are my actual gauges just shot? anything else I can do here for diagnosis and repair? I doubt the gauge itself is serviceable, but what do i know.

Next project, pipes. My OEM muffler sounds like a rattle can with all the rust and broken baffles shaking around. No good. But a Harley dealer in town is selling all their brand new take-offs for $50, so I'm heading that way later in the week to see if I can't score a nice set.

Then it's down to cleaning connections, replacing fork tubes, tires, and a few carb seals/o-rings and I should be ready to hit the road come spring.

[old_smokey]

Here's a few pics of the 7V test. Also I noticed the wiring diagrams for the 75-77 don't match the colours of all the 75. Like the 7V regulator for example, different colours. Is there a 75 specific diagram out there?

That aftermarket switch laying on the side is for the headlight. Not sure why. I think it has something to do with a fairing that came with the bike.

[Irishman1]

Been following. I mainly restore 75-gl1000’s (8) and have had many of the same problems you’ve in countered. Lots of fun and very rewarding. The carbs can be a challenge as you know. Sounds to me that the carb with hanging idle is running lean. Looks great. Keep it up