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1985 GSXR750f Restoration

49K views 191 replies 39 participants last post by  Down South 
#1 ·
Hi Forum,
New member and first post so I apologise if this isn't the right place or if this is duplicate thread.
After 4 years of searching within New Zealand, I found and bought a ROW model 1985 GSXR750F. Unfortunately sins from the previous owner included chopped rear fairings, polished frame, painted bits and pieces the wrong colour etc.
However, all chassis bearings have been replaced, fork tubes are new, tank and dash are in good condition and it's a runner-although very poorly.
Chassis no. is 107298 which was the 70th last one and only 4 older than Karitani Pete's one.
Over the last 3 months I have sourced all the parts I need to begin a full restoration-including some still in original packaging NOS belly pans and r/h mid fairing. RDDecals and Airtech have also delivered fantastic parts.
Currently working on carbs and was surprised to find all internals are available from Suzuki, apart from some orings from Oz.
I have been trawling through this forum for the last 3 months and just wanted to say the information and knowledge available has been invaluable.
If anyone is interested, I'll keep posting. Anyone from NZ, would be keen to hear from you.
 
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#3 ·
The intention is to return the bike as close to OEM as possible - if I can get half the result as some of the restos in this forum, I'll be very happy.Couple of quick pictures. Have been a bit slack with photos - too keen to get into it.

The PDF is a picture from previous owner and is how I bought the bike. The next couple show some slow progress - but have been lucky to find replacement OEM frame covers and tail fairings. Have fitted them up with new OEM fairing rubbers, brackets, licence plate light and cover. Have also trialled a way to return the polished frame back to the anodised mill finish - Scotchbrite silicon carbide finishing pad with WD40 as lube and will soda blast the cast sections. Still to decide whether to re-anodise or clear coat the frame.
As I started, I've realised there's a huge amount of parts still available through Suzuki. Not the cheapest way to complete a project, but will help with the overall result.

Next couple of photos show carb overhaul progress. Previous owner couldn't get carbs tuned right, so found a second bank in really good internal condition with the intention to overhaul, rekit and swap onto bike. So far-full disassembly, cleaning with a mixture of elbow grease, WD40, engine degreaser, and ultrasonic cleaning. Have sourced gaskets and orings from Wemoto (UK) and Go-and-Show in Oz. Full set of needles, pilot, main and needle jets, needle valves etc from Suzuki. Also fitted radial lip seals in place of the throttle shaft felt rings originally installed (thanks to JBM for that archived tip).

Original plan with bike was to complete it over 5 years, but I've caught the 'bug'. Without trying to rush, the new plan is now to get it completed for the 30 year anniversary in 2015.
 

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#5 ·
Wow, that bike was only rebuilt from the frame up in 2012. They went a bit custom with the black on the frame and the wheels etc but spent quite a bit of dough I think, saw the build thread on Kiwibiker. Mismatched fairing panels are part of your restoration pre-paint, or did some other owner since him bin it and just chuck them on?

I'm surprised the bikes running rough after all the time and money poured into it, he sell it straight to you in July or was there some owner in the middle?

Here was the initial build thread, looks like he put a lot of good work into it - although like you I'd much rather see original fairings etc not the paint job he ended up with.

http://www.kiwibiker.co.nz/forums/showthread.php/121716-1987-GSXR750-rebuild?highlight=Gsxr750

Incidentally I purchased my 750 from Invercargill and did a mission down to pick it up a few years ago, good times. Not so much once I found out the engine and shocks were stuffed, but still.. haha
 
#6 ·
Wow, that bike is clean! Welcome to the site. You'll find lots of knowledgeable folks here and a few members particularly knowledgeable are in AU and NZ.

My bet regarding the rough running condition is that the carbs are gummed up. If they aren't run, the VM29 carbs will get gummed up. You should be able to clean them up and all will be good.

Mine went through quite a metamorphosis as I got it back in shape so I'm looking forward to seeing how yours turns out.
 
#7 ·
Hey Guys,
I'm humbled that some of the forum 'pioneers' are interested in this thread-Cheers.

Fruitloops-bought the bike from the previous 'restorer' in July and the first thing I did was ditch the chopped rear fairings and frame covers and source pre-loved slabside panels from wreckers all over NZ-doesn't seem to be many good bits left. Have fitted them up as part of the 'get it all together and then strip it down' process.

Apart from being assured that it was a runner, it holds a 3000rpm idle with the idle screw backed off, blows black smoke and clears itself when riding at about 5000rpm. Instead of 'polishing the turd' I found a set of relatively unmolestered carbs which will be fitted up after a complete internal rebuild.

Glad to hear you survived you visit to Invercargill o.k.
 
#8 ·
Oh, here's a tip. Get an ignition advancer for your bike. I'd recommend this for any 1st gen GSXR 750. Since I put mine on at the start of the year I'm constantly amazed at how smooth and linear the engine is. I've got a Factory Pro unit with a +5 degree advance.
 
#9 ·
Hi awasson, it's an honour for me to have you posting in my thread-you guys are amongst the Oil Cooled Gixxer gods!

I started down the clean the carbs route but quickly found issues with the pilot jets being so over tightened at some stage they have a step in them and appear to have damaged the seats in the carb body. A/P nozzles have also been epoxyed in place and the throttle shaft felt seals are so worn, they may as well not be there. This is why I started again with a spare set that didn't look like they had been apart before

Hopefully carbs will be on bike by next week and after sync, bike will be a runner
 
#12 ·
Hi Andrew,

I'll definitely draw on your guy's knowledge and experience and will try and post regular updates-mind you it doesn't take much to lose a couple of hours when you're on a mission- only to find you have no photo record when you're finished.

Great collection of bikes you have. A mate of mine had an 89 RR years ago but traded it on a new '96 750 to keep up with the race to have the latest bike.

I'm keen to go with the Dynatek 2000 cdi and mini coils- but maybe next month (the credit card has been in competition between bike bits and basic life necessities like food!).

A couple of quick questions-what causes a jet needle to spin round in its E-clip and therefore cut through the groove? (I've noticed this during the 'out with the old-in with the new' carb overhaul).

Also did all red and black 85's come out with red seats, or did some countries have black seats?

Cheers,
Roger
 
#13 ·
Hey Roger,

I'm not sure why the needles would be spinning and cutting through the groove. Maybe start a new discussion and title it with "VM29 Flat Slide Needles Spinning" or something like that. It should attract the attention of Ozboy. He's got a lot of experience with servicing those carbs.

And yes, the seats did come in red. I had never seen them in black until seeing some of the bikes from other parts of the world. I'm pretty sure all the red/black 1985 GSXR's in Canada came with red seats.

Here's a picture of my bike in OEM trim in 1986. It had some scrapes and scuffs from a year of production racing and the exhaust heat shield was torn from "falling in the pits" so I removed it completely:



Take lots of pictures of your project :biggrin
 
#14 ·
I think the H model JDM bikes had black seats.

As for the needles spinning issue, I would check to see that the packing washer is in place and it is the correct thickness. (part #7).

Auto part Axle part Transmission part Automotive engine part Diagram


Nice project you have started - keep us posted on the progress (with pictures)

Oz
 
#15 ·
Thanks Oz,

Noticed needle grooves worn during the 'out with the old and in with the new' carb overhaul. Packing washers were in place and there is a slight linear clearance between the connector (5) and the e-clip when assembled - enough to allow the needle to rotate if it had to - but it looks as if it has spun in it's e-clip and worn the groove down. Have included photo below. Asked my local Suzuki mechanic and he commented 'they do that', but couldn't say why.

Currently fitting up new carb bits, so will see if new packing washers and e-clips are still available. Most other parts still seem available.

Bike is a good platform to start with, but still needs a heap of work to fix restoration sins of previous owners. Thanks for seat advice - might have to return it back to red.

Cheers Guys.
 

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#16 · (Edited)
I see what you mean now. And yes, I have had the same on one of the needles on one of the sets I rebuilt for my bikes.

My guess is it won't get any worse, and the needle will still be held at the right height. The packing washer should be just thick enough to stop the needle having to much vertical clearance. If you are worried about the clip falling off, put the packing washer on top of the clip so that the clip sits deeper in the hole in recess of the slide (BUT you will have to do the same on all 4 carbs).

Oz
 
#22 ·
Hi KP,

Will definitely investigate that further. I have been really lucky over the last 3 months to have located all the slabside fairing panels I need to make the bike complete again (even if they are miss-matched colours and models - eg. I'm sure the tail fairings are Canadian model going off the decals and reflector mount holes). Best find was NOS 85 belly pan lowers!

Still keen to locate a R/H mid fairing. I have a NOS in blue and white, but it seems like 'Gixxer Sacrilege' to gouge the decals off and sand the paint back to turn it all black and red.

Do you know the history of your '85? I'm pretty sure my frame number is only 4 older than yours.
 

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#18 ·
Hey Oz,

Measured clearance between needle E-clip and underside of throttle slide - pretty much 0.2mm across all carbs (photo below). I'll try and order new spacers tomorrow before carbs go back onto throttle shaft.

Maybe I'm being too anal - have installed new jet needles as part of the overhaul and the old E-rings are now tight in the grooves and would probably take years for the needle groove wear to occur???

Your thoughts?
 

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#19 · (Edited)
If I could find a specification for the needle float then I would think that is in range, so I probably wouldn't order the packers unless you really wanted to. You will probably find they will be within a bee's dick of what you already have.

Also looking at the slide, it looks like you have the genuine '85 VM29SS's if I'm not mistaken. I don't think the later VM29SS's had the over-lift pins (but I have been wrong before).

Oz
 
#20 ·
Also looking at the slide, it looks like you have the genuine '85 VM29SS's if I'm not mistaken. I don't think the later VM29SS's had the over-lift pins (but I have been wrong before).

Oz
Hey Oz, were there 2 versions of the VM29 for our bikes? If so, what's the difference?

Thanks,
Andrew
 
#21 ·
Only minor variances, and none that would give any performance benefit. The ones that I know of are the '85's with the 27A01 carbs had the over-lift pin on the assembly that connects the slide to the operating lever, the venturi front plates were slightly different (27A02 and 27B20 front plates will not bolt onto 01 bodies) and I think some or all of the B20 carbs had plastic floats.

There may be more, but not much point hunting down a particular version as they can all be set-up to perform exactly the same.

Oz
 
#23 ·
That is some beautiful stuff right there :biggrin

It seems there are more 1985 parts down south than here up north. When I had to source parts for mine (stolen), I got one mid from eastern Canada, belly from California, other mid from mid-west USA, upper from Sweden.

Maybe you can find someone near you to trade that blue/white mid for a black one. I agree, it's sacrilege to sand down and paint when it's mint condition like that one.
 
#30 ·
After a couple of weeks of disassembling, cleaning and complete re-kitting with OEM parts, the VM29SS carbs are banked-up again.

I've spent a lot of time and $'s on these in an effort to ensure they're the best they can be - I was really disappointed when the bike didn't run as described by the PO in his 'For Sale' advert (actually found a thread describing starting and idling issues from him on this forum which he posted 1 month before selling - thanks Laava!!!:thumbdown). If the bike still doesn't run well with these on, I'll be confident it's a problem somewhere else.

Thinking of bench testing the carbs before fitting to bike to check; float bowl fuel level (needle valve operation), fuel leaks, accelerator pump circuits etc.
 

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#40 · (Edited)
I was really disappointed when the bike didn't run as described by the PO in his 'For Sale' advert (actually found a thread describing starting and idling issues from him on this forum which he posted 1 month before selling - thanks Laava!!!:thumbdown)
Right - after a full carb rebuild, new intake pipes and O-rings, valve clearances adjusted (some had no clearance at all), cam lobes checked for service limit, cam timing checked, head studs re-torqued, poor coil earthing remedied, exhaust flange bolts re-torqued...

- the bike started after only a few cranks :woot. With the pilot screws set at the OEM 1/2 turn out, the engine would hang on to the revs, so another 1/2 turn out and it settled down to a nice idle. After a quick ride, I noticed it had a slight hesitation just on throttle opening - so another 1/2 turn out on the pilot screws. Now it idles, revs freely and returns back to idle with no hanging, no back firing, no black smoke.

I'm absolutely stocked! I'm surprised how well these engines go :biggrin The work over the last three months has been well worth it.
 

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#32 ·
While waiting on some new inlet pipes before I install the carbs, I'd thought I'd check the valve clearances and cam lobes for wear.

Apart from some oil staining and residual grime, I was absolutely stoked with the condition of the gear under the valve cover - the bike has 75k km on it and I was expecting the worst. The cam lobe heights all measure well above the service limits and apart from the odd pit and polish mark, the lobes and followers all appear in very good condition - maybe a tribute to regular oil changes over the last 28 years.

One thing I was surprised by was the very steep lead-in on the open side of the intake lobes - the face of the lobe appears flat before an 'edge' and then the top radius. I suppose this is to ensure the intake valves open quickly. Does this profile seem normal?

Valve clearances were also too tight - some intakes only had 0.04mm - a valve partially open would certainly contribute to the bike not running well.
 

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#33 ·
Hi

Just a small piece of advice that you will probably know already. My experiences with carbs is always do the valve clearances first as the carbs will never balance properly without having first done this. Even when the carbs are closely balanced there will always be some low end drag without the valve clearances being done. I've had four slingshots and always do the above, and many other bikes.

Screw Loose
 
#34 ·
Yup, that cam profile looks pretty much the way mine looks.

I pulled the valve cover off mine last year after several years (and probably 30,000 Km) of not checking valve clearances and I was utterly surprised that they weren't out of adjustment. In fact mine were spot on. I had to check several times just to be sure. I was seeing a little weeping between the head/cylinder block and the block and the base but after I retourqued the head everything was fine.

It's a testament to how well these engines were engineered. I think this winter I'll be attending to the valve guide seals. After some 28 years of action, they are probable fairly well done.
 
#36 ·
Yup, that cam profile looks pretty much the way mine looks.,

It's a testament to how well these engines were engineered. I think this winter I'll be attending to the valve guide seals. After some 28 years of action, they are probable fairly well done.
Thanks Andrew for the cam profile confirmation-I'm still really surprised by the good condition of my cam lobes. I remember checking the clearances in my '93 ZXR 750 back in the day and at 20k kms, the lobes showed significant scoring and wear.

I agree with the testament to the engineering of the motor-everything under the valve cover, at least, seems to have wide running surfaces, is well bearing'd and bolted down well.
 
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