1981 Gs450 TX rebuild... "Scarlett"

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So some of you may know me from some of my posts around the forum asking questions about my bike. I have learned a lot and decided to start a rebuild thread for her. Please note that almost all of my early concerns are functionality and safety.
She will not be the prettiest bike on the forum. I live in Oregon so I will have many winters to come to get her looking her best. For now I want to experience riding and enjoying her.


I am organizing my photos and posts.. For now here are pics of when I brought Scarlett home and her story.

I found her in my father-in law's barn. She was purchased in 1981 off the showroom floor by my wife's grandfather and he put about 7,000 Miles on her before laying her down and deciding he was not cut out to ride anymore.

Pat (My father-in law) put her in the barn to be looked at later. Fast forward 25 years and a few mystery repairs, More on that, to when I found her.
This is my first bike and I fell in love with her as soon as I saw her. I love the look and feel of the bike and she meets my vision of a functional as opposed to flashy or race type look.

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Basic Maintenance.. Battery and Starter..

So I bring her home and as you can see she needs some love..

Initial inspection shows mostly cosmetic and age damage only. Some scratches and the headlight is askew from laying her down.. Heavy layer of dust and grime from sitting in the barn. Needs new rubber from tires to carbs..

I note that the battery covers are removed and she shows signs of having been fiddled with. Mystery Repair number#1

First order of business is a I quick wash of the bike and basic maintenance.
I have worked on cars but never bikes but battery test,starter test, compression test, Spark test.. and so forth.

I purchase a new battery, old battery missing (MR#1), new plugs and a compression tester.

I get the new battery charged and remove the old plugs which actually appear in decent shape, the new plugs are gaped and ready.

Install the battery and check ground wires and everything appears good.
Turn the key and the lights come on.. YES!! Electrical at least functions on some level..

Check the kill switch and press the starter button. Bike produces a loud click noise and nothing else happens. Check switches and same thing happens. Refer back to my vast knowledge of starters and solenoids(Dads old ford truck and moms project Beetle) and decide this means the solenoid is good. Decide to check power at starter and inspect starter.

The starter cover is a good representation of the grime I will be fighting on this bike. For now if it works it stays..


Power checks out at the starter pole but still nothing even when I hook up the starter straight to battery. (Ground a leg and hook up the power to the pole)..

Pull the starter and disassemble.. Note marks the indicate its been opened before (MYSTER Repair#2)

Looks like an easy fix. One of the brushing springs is loose. Rewind spring and test and starter spins.. YES!!!

Install starter and attempt to turn her over... Starter does indeed turn but bike is not turning over. By this mean it does not sound like the starter is physically turning the engine over but the starter is turning.

I remove the starter and check the starter flywheel in the engine and it does spin freely in one direction but has tension in the other...

Hook the starter back up and note that its spinning.. In Reverse..

The spring needed to be replaced and then the starter was good to go..

Bike now attempts to turn over.

Next up is compression test !!!

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Basic Maintenance.. Compression Test

So I move on to the compression test. I get her all set and test the right side.
Almost 150


Now for the left..
Not as great but over 120


Decide to move rapidly on to the spark check...

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Basic Maintenance.. Spark Test.

For the spark test I simply connect a spark plug and ground onto the engine block.

I get a nice big blue spark off each one..

Decide to call it good for now and move forward..

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First attempt to start..

I decide everything is going so well I might just get lucky and crank her over..

Note.. This is before I found this forum or I would have cleaned the carbs and replaced o-rings before attempting..

set the bike on prime and give her a few..
check that I have fuel in both float bowels by loosening the drain screws. Fresh gas so getting flow..

Attempt to crank the bike and she turns but never fires.

We spray some starter fluid in the air box and attempt to crank her. Starter fluid is immediately sprayed out of the air box. This seems strange.. Decide to investigate further. Air is indeed coming out of the airbox and also the exhaust..

Decide to check the valves and timing and so forth.

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Mystery Repair #3 Timing Adjustment

This mystery repair looms the most as it seems to have caused all the other issues I have had with the bike but more on that later..

We decide to remove the valve cover and check the valves and timing. This is where everything decided to go down hill..

The inner bolts on the valve cover come out nice and clean but every outer bolt is rusted solid and the head of the bolt comes off like butter. Valve cover is not coming off.

Do and quick check on E-Bay and new valve cover and Gasket will be 30.00

Decide to bite the bullet and drummel the cover so we can continue.




Valve cover is now removed and engine is super clean and looks new..



Follow instructions in Clymer for Timing and discover that the valves are 180 Degrees off their intended setting. Not sure why this was adjusted but leads me to believe that Mystery Mechanic was not taking his time..

Set the valve timing correctly and decided to see if we could get combustion before we replaced the carbs.

We used and eye dropper and placed a small amount of gas into one cylinder.. Hooked up the power and voila we had combustion.. Repeated on other cylinder.

Moved on to second attempt to fire.

[7981GS]

It will all be worth it.

Watching your progress on this one...


Eric

[Guest]

Definitely tuning in for this one...

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Thanks for the Comments..

Hey guys..

Just wanted to say thanks for the posts. Knowing someone is reading makes it worth it.. Well that and getting to ride Scarlett for the first time..

BTW I am starting a new job and just had a baby girl 2 months ago, so post's may be random and spaced apart LOL..

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Second attempt to fire.. Hanging idle.

So here is the second attempt to fire.. This was one of the best days and if you watch the video you can hear me being very excited

We jimmied the valve cover back on with the good screws and replaced the carbs..

http://www.youtube.com/watch?v=7cS8Pn5Oojw

As you can see from the video she ran nice and smooth.. Did I mention I was excited!!! I am the one working the camera.. Dan (1984 Kawasaki KZ100P with full police package) is the one firing the bike. He has been a true friend during this process and even supplied the new starter brush spring from an extra starter he had from his bike..

We enjoyed this moment for a bit and let her sit at idle..

I decided to rev her a bit and she what she idled at.. The tach displayed some interesting behavior.. It acted more like a compression or max gauge then a true tach. This means that if I revved her to say 2K the tach would swiftly move to 2K then take 2-5 seconds to settle back to idle speed.

I also noticed that if I revved her up to about 3K or so she would hang. Sometimes even requiring me to shut her down as she would not return to idle..

These were peculiar behaviors.. Again I have worked on cars but never worked or restored a motorcycle.

The upside to all this is that I found this forum and after some research discovered that the hanging idle was due to dirty carbs and old intake boot O-rings.

I also found a repair guide for the tach..

Simply cut her open and worked some lube in there.. Or there seems to be a simpler way now..

http://www.thegsresources.com/_forum/showthread.php?t=154297

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I would have gotten away with it.. If not for those Pesky Screws..

So hindsight being what it is.. I realize now that I am about to make a fatal error in judgement..

I decide that while her current state is exciting I still have a long way to go..

Can she shift gears?
She is in Neutral according to the Gear indicator light.
I also noticed while starting her that there is at least 60% play in the clutch then pull hard to get the clutch fully engaged.. Decide to remove clutch cover plate and clutch basket. We will separate and oil all the clutch plates.


Can we correcting the hanging idle?
I decide to soak the carbs and replace all o-rings including intake boot O-rings.

Pesky Screws.. FATAL ERROR IN JUDGEMENT!!!
Removing the broken valve cover screws proves quit the challenge.. I decide that EDM removal is the only option.. ( Machine shop tried and failed with all other means of removal)
I REMOVE THE ENGINE INSTEAD OF THE HEAD..
I should have called it even and rebuilt the top end and let the EDM machine works its magic only on the head instead of the entire engine. The EDM Process created metal Aluminium and Steel shavings which would prove disastrous later..

The EDM process does indeed remove the screws..

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Clutch Play repair and Carb Rebuild... The Second Domino..

The clutch repair goes as smooth as butter. We simply remove the screws and covers and then the clutch basket. We followed the Clymer guide on this one.. We separated and oiled all plates and once installed the clutch worked normally..

I received my new o-rings for the carbs and intake boots and proceed to cleaning the carbs..

Little did I know that I was about to make a major mistake and place the second domino in the chain of disaster..

I disassemble the carbs with no issue and soak them for 24 hours.. I install new o-rings and assemble carbs. Somehow in this process I MAKE A HUGE MISTAKE and install one of the needle jets incorrectly


I somehow manage to install the needle jet upside down on one cylinder...

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Disaster!!!!!!!!!!!!

I install the new Intake O-rings and the cleaned carbs..

I must say that I am excited and that my anticipation of a good outcome probably contributed to my disappointment and not thinking the symptoms through..

I attempt to fire her after the installation and nothing is the same..

She is hard to start if at all.. She can maintain minimal RPM and any attempt to give her gas kills her.. I feel like my heart is broken..

I attempt to adjust the idle screws and blame the carbs.. I want it to be an easy fix so I never think to remove them and inspect my work..

The bike gets so that she will not start without using starter fluid.. I continue to believe that all will be well if I turn one more screw or clap my hands or maybe just wish harder..

Scarlett refuses to run.. No amount of anything will make her start.. The battery has even given up on me at this point..

I should have stopped.. I should have known.. I should have done more to save her..

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Aftermath.. It's worse than that... She's dead Jim..

I survey the situation..

I pull the spark plugs and they are black..

I put the battery on charge and think it through.. The carbs must be the answer...

I decide to pull the carbs and run another compression test.

Scarlett is DOA.. She reads 80 PSI on both Cylinders..

How have I allowed this happen.. Where do I go from here..

I decide to take a breather and focus on the birth of my child and moving closer to family..

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Good news!!!!

So finally had the time and money to start a top end rebuild and my compression issue were bent intake valves.. If they sit just right its all good but as soon as they spin then all my compression goes. New updates and photo coming very soon..