My GK76a winter service/tidy-up project.

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ventYl
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Re: My GK76a winter service/tidy-up project.

Post by ventYl » Sun Mar 26, 2017 7:18 pm

Did you try to pump enough times? I Guess you pushed your brake pistons all the way in while service. You have to pump a dozen times or more in order to pump enough fluid so the pistons will make a contact with pads and these will stop the wheel. While this happens it can feel like there's no pressure in system.

Q: If you open brake fluid reservoid and unscrew front calpier bleed nipple is there break fluid flowing out of nipple? It should.

moforockband
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Re: My GK76a winter service/tidy-up project.

Post by moforockband » Sun Mar 26, 2017 10:39 pm

It will only flow out of the nipple if you don't have the reservoir top on. good tip though.
You would be best getting 2 syringes, a nice large one to pump lots of fluid in one go in a reverse type fashion up into the reservoir, and a smaller one to return the excess back to the bottle once it's full.
Reverse bleeding is usually effective, but you must make sure the pistons are pushed fully home before starting, otherwise you end up with more air pockets for things to go wrong! Nice thick new pads make it easier and quicker too.
If you don't get the results you want immediately, leave things to settle for a 5 minutes to allow the bubbles to collect and be easier to get rid of.
Brake fluid will always de-aerate if the bubbles have somewhere to escape upwards.
Another tip is to use ptfe tape on the threads of the bleed screws so you can open them a whole turn, and get some real fluid movement thru the system without it leaking all over the caliper. Don't push too hard on the reverse syringe, as although I have never managed it, I've heard you can damage the master cylinder.

Hubbskiboy
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Re: My GK76a winter service/tidy-up project.

Post by Hubbskiboy » Sun Apr 02, 2017 10:17 am

Hi Mofo and ventYl,

Thank you both for your input on this tricky job.
The problem was that I was getting just brake fluid (no air) from both nipple bleeds, but still no pressure.
The good news is that I have now solved the problem and I have pressure in the system, although both levers are still soft.
I'm hoping the old 'zip tie the levers down and leave them overnight' trick will improve things.

To help anyone else experiencing these problems with the braking system, this is what I did -
I bought a small tin of red caliper grease and greased every thread in the brake line including the banjo and brake bolts.
There were a lot of threads on the front as I'm using the Goodridge 'Buildaline' system, which may have been a mistake! :pray:
Once that was done they tightened up much easier and it looked like I could get a lot less thread showing.
I also purchased a £20 Bergen Brake Bleeding System (see image below) to make the process easier than syringes.
It makes it much more of a one man job.
After running about 3-4 reservoir amounts of brake fluid through the system and whacking the components with a small rubber mallet, I finally got pressure in the system.
Just to make a point and I think it's a good tip, I found putting the red caliper grease on the threads of the bleed nipples particularly useful as it stopped any fluid seeping out even when the nipple was fully turned.
So that's another pain in the ass job done. :grin:

Image

Hubbskiboy
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Re: My GK76a winter service/tidy-up project.

Post by Hubbskiboy » Sun Apr 09, 2017 6:09 pm

To confirm, I've just checked the front brake lever and it's now stiff as Johnnie Keyes. ;)
The zip-tie trick really does work well.
Just need to do the same with the back brake now.
Getting some brake leakage from around a couple of the brake banjo bolts, so will need to tighten them up a bit more I suspect although I didn't really want to go all the way to 20Nm if I could get away with it (16Nm at the moment).
Not sure why they would leak if I used brand new copper washers and the contact surfaces were level.

Hubbskiboy
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Re: My GK76a winter service/tidy-up project.

Post by Hubbskiboy » Fri Apr 14, 2017 11:37 am

Hi Wullie,

Hope you're doing ok?
Just looking at sorting the valve clearances now.
When you stated on the very first page of this blog, "Removing the shims was a dawdle. :grin: Gently lever each rocker to one side, push it down so it snagged onto the side of the shims' recess & fish the shims out with a magnet."

How exactly did you lever the rocker to the side?
I've had a go at pushing mine with my hands and they are pretty solid.
I suspect you used an implement of sorts?
Don't want to to damage anything, so if you could let me know what's best please.

Ta,
Hubbskiboy.

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Variablevalves suck
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Re: My GK76a winter service/tidy-up project.

Post by Variablevalves suck » Fri Apr 14, 2017 2:32 pm

i usually use a pair of circlip pliers , works well.

Hubbskiboy
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Re: My GK76a winter service/tidy-up project.

Post by Hubbskiboy » Fri Apr 21, 2017 9:17 pm

I've managed to source a pretty good nick swingarm from flea bay for £33.00. Result! :grin:
Been after one without any gouges, scuffs, dents or lugs missing for about a year.
They sure are rare. It's even got most of the original silver anodising in place.
I'm going to buy the titanium removal tool that features most frequently on eBay, but can anyone provide an accurate detailed procedure how to remove the swingarm and replace it on these bikes?
It seems massively overcomplicated with various weird nuts and bolts.
Torque settings would also be much appreciated.
Again the Jap manual doesn't provide much detail about the procedure.

Cheers all.
Hubbskiboy.

wullie3xv9
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Re: My GK76a winter service/tidy-up project.

Post by wullie3xv9 » Sat May 13, 2017 10:57 pm

Hi folks. :grin: Apologies again for my rare appearences on here these days, work is being a major pain in the ass again. We've had the driest weather since the early 70's up here lately, but by the time I get home from work & have something to eat I can't be arsed doing anything in the evenings except sleep! Anyhow. Hubbskiboy, I'm chuffed you've finally found a swing arm that's in good nick & you've cracked bleeding your brakes. :grin: I bought a used front pair of pre-made /sealed GOODRIDGE hoses & had no difficulty bleeding them. There's very little front lever travel on mine either.

As for mine, when I've had a bit of time & the energy, I've finally started to chip away at servicing it plus doing all the jobs that were put off last year, which has been kick-started by the L/H fork seal springing a major leak! :roll:
( Caused by the too soft front forks diving over unseen pits in the sliders chrome ).

First on the "to do list" was draining the engine oil & replacing the oil filter & then draining the coolant so I could fit the ebay purchased, BLUEPRINT 88 deg. C thermostat I bought over a year ago!
(The NGK CR8EK spark plug gaps were also checked & were all still bob-on 0.7 mm after 3,000 Kms / 2,000 miles :o ).
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The positioning & typeset of the stamping are identical when compared between the Suzuki boxed (L/H) & the BLUEPRINT boxed (R/H) thermostats. ( Both thermostats are 44 mm in diameter. The BLUEPRINT one I bought fits several SUZUKI 1.3 Ltr petrol engined car models ).
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Next on the list was replacing the O-ring seal on the starter motor. Being a masochist I decided to dismantle the starter motor, firstly to check the state of the (four) brushes & also to clean up the copper comutators ... which were filthy! I used some acetone on a cloth & some very fine emery paper to clean & polish the comutators.
It took four attempts to get it back together again due to the brushes & springs, but at least it spun when I pressed the start button. :grin: I fitted a new 25 mm I.D. X 3 mm X-section Viton O-ring to the starter before refitting it the engine.
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Today I removed the wheels & forks, firstly to replace the forks seals & fit the stiffer HAGON front springs, and secondly, I bought a pair of BRIDGESTONE BT016 tyres over the winter ( for £122 quid, inclusive of "free postage" ) to replace the mis-matched DUNLOP Qualifier on the front & BT021 on the rear.
Hopefully the combination of the two jobs will improve the feel / handling of the bike. :pray: :grin:
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My target is having it all done for the Cadwell track day weekend at the end of June ... but ... the "fly in the ointment" is I'm gonna be working up in Morayshire for the 3 weeks leading up to it ! :roll:
I may need to take a week off work to get it all done in time ! ( That'll upset The Mrs :grin: ).

More as & when .... ;)

Wullie.

wullie3xv9
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Re: My GK76a winter service/tidy-up project.

Post by wullie3xv9 » Tue May 16, 2017 4:53 pm

Hi folks. I've managed to get a couple more jobs done since my last post. :grin:
I was working over the weekend & managed to get both forks dismantled there, firstly to replace the leaky L/H fork seal & secondly to check the state of the "guide" & "slide" bushes as I only replaced the fork fluid when I serviced / tidied up the bike originally. Considering I flushed out the forks when I first serviced them, the old fluid was an 'orrible colour even tho' it's only done approx 3,000 Kms !
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I've got a pair of OEM "guide" bushes on order as the ones fitted have been damaged by pitting on the bottom of the chrome sliders when they've been dismantled in the past. ( I always go over any pitting before dismantling with a fine riffler file & fine emery paper to prevent this happening ! :roll: ).

Today's been a productive day. This morning I took the Gixxer's wheels in to a local m/cycle shop & had my new pair of Bridgestone BT016's fitted & balanced.
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After that was done I then took my 3XV TZR for its MOT which, thankfully, passed with no advisories. :grin:
After returning home & a bit of lunch I got stuck into the Gixxer. I concentrated on removing the carbs & moving the airbox forward today as I've had an issue with finding crap under the carb diaphragms every time I've had the caps off to adjust the needle heights ! :roll:
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After looking at GK76 airboxes on Ebay a while back it finally dawned on me what the crap was & where it was coming from ... the carb breather filter housing.
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On trying to carefully lever out the piece of foam filter it just disintegrated into powder !
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Mystery now solved, after cleaning out & blowing through the carb breather filter housing I made up a filter from a couple of pieces of two ply air filter sheet thus ...
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With that sorted & the airbox refitted I turned my attention the the carbs. The first job was cleaning out the disintegrating carb breather filter debris from the top of the carbs ... yet again ! ( Hopefully that'll be the last time for a while now. :pray: ). I also swapped the #112.5 main jets fitted for #110's to see if that improves the top end throttle response further. As it's easier with the carbs removed I checked the mixture screw settings, which were anywhere between 2 & 1/4 to 2 & 3/4 turns out ! :whistle: They're all now at 2 & 1/2 turns out. I also dug out my trusty piece of 0.8 mm stainless locking wire feeler gauge & checked to see if the butterflies had wandered out of adjustment with each other. Both outer butterflies ( 1 & 4 ) were open fractionally more than the two inners ( 2 & 3 ) so were adjusted to match the inners. Lastly I squirted some SILKOPEN down the throttle cable before refitting the carbs.
Typically for up here, it started chucking it down so I had to stop working ! ( I've nowhere at home to work inside ).

'Til next time ... ;)

Wullie.

moforockband
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Re: My GK76a winter service/tidy-up project.

Post by moforockband » Wed May 17, 2017 9:33 am

Good work. They are quite tricky to fix and nail down certain problems on these wee 80's bikes aren't they!


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