-84 GSX 750EF after 24 years in a barn

[carl_87]

Hi, this is my first post on the forum! I found it just a few days ago and it seems to be a place with good people and helpful spirits.
I'd like to share this old girl, she's an -84 GSX 750 EF that has about 35000km on the clock and hasn't been run since around 1997.
It belonged to my step father, but being a farmer with too little free time on his hands to give this bike the attention it needs, his wife, my fiancee and i coaxed him into agreeing to give it a new home.

The plan is to get it running and see about doing a minor restoration. The ambition level with the restoration is not musem-level, but i'd like to keep the stock look for now. The bike is older than i am, but many good things stem from the eighties as you know.

Her place in the barn, more or less stuck in the ground where she stood.

Loaded her on a trailer and brought her home, together with various other findings from the barn.

Home and ungraciously unloaded, wheels were quite stuck so my fianceé and i needed to push the bike together. 

 

After 24 years in a barn, it's time for some cleaning

Removed lots of things for cleaning. Frame and engine looks quite nasty. No battery but everything else looks to be where it should.

 

I'll post some pictures along the road, this is my first bike ever and the only experience i have with carburetors is from an old moped. It was smaller, simpler, and most importantly not four..

Cheers, Carl
Sweden

Edited October 5, 2021 by carl_87
Added picture

[carl_87]

I could not figure out how to upload a movie with sound so i made a GIF. You have to use your imagination, but she says BOOP BOOP like expected

 

[Blubber]

mmmh... Swedish girls 

 

Looks like a nice project (and a lot of space for it too )

 

Welcome from the Netherlands btw

[denisd]

Welcome and now the fun begins, best of luck lad. 

[Swiss Toni]

Good find! Loads of potential. Welcome to OSS. 

[TonyGee]

that'll keep you busy for a while  

[carl_87]

Thank you for the kind words.

I started the project about three weeks ago and have been doing some work on it. A calming factor is that it ran well before it was put away.

I removed and drained the tank of the old fuel, it still looked good but it was over twenty years old. Removed the carbs and took them apart. Number 1 carb had brownish gunk in the float bowl and the brass jets were quite corroded. Cleaned it out, took out most of the jets and gave them some care. Did the same with the rest of the carbs.

Hello carbs

Does anyone know the model name of these beauties?

I put the carbs back on the bike, put the tank back on and poured in some new fuel. After about a minute, number one carb started dripping fuel so i took it apart again. Second time over i figured out how the float needle is supposed to work (like i said i'm new to these...floater thingy..fuel..thingamajigs. I now figured the needle is supposed to move up and down with ease, mine was somewhat sticking). Cleaned it along with the other float needles, put everything back and voila, no more pissing fuel.

Checked the plugs and they looked good. Poured some oil in the cylinders and let it sit for a day, then i carefully turned the engine over by hand. No problems whatsoever.

I emptied the engine of the old oil, put a new filter in and new oil.

Checked a plug for spark, which it had, and figured "what the hell, let's try starting this thing".

I cranked the engine over with the starter for a while, without getting it to fire. Sprayed some starting fluid in the carbs and got an immediate sputtering reaction. Then i tried full choke for a while, and she roared to life, at a zesty 3000 rpm! Dialed back the choke and the revs dropped to a more modest 1500.

Then i heard it. A strange, clacking noise. It was the clacking of metal against metal, paired with a squirting, dripping sound. I then noticed a large puddle of oil under the bike, a puddle that had not been there the moment before, and it was growing by the second...

To be continued...

 

Edited October 5, 2021 by carl_87

[tobar]

ooh i like a good murder mystery...

[denisd]

Oops 

[TonyGee]

just like old ladies, they tent to leak with age   

[carl_87]

Chapter 3 - The plot thickens

I turned the engine off and looked at the mess that had unfolded. A couple of litres of oil was puddled on the garage floor.
I started by securing the crime scene and brought out rags, sand and whatnot and did some cleaning. I looked at the filter cap area in the lower front part of the engine where the oil was still dripping out, and decided that the now visible gap between the cap and its seat had not been there the minute before. I also concluded that the oil that was now on the floor must have been hiding out of sight behind the cap a minute earlier. Mysterious.
Turns out two of the three double ended studs used for securing the cap to the block had torn grooves, and the nuts that were supposed be tight on the studs had moved a few millimetres farther out.

Hello there, stud. The grooves were not this bad all the way, only the outer bits. The rest of the grooves got wrecked when i screwed the studs out with a pair of pliers. 


After this, i decided the night was late and that this could wait 'til the morning.

I replaced these with two new bolts from my box-o'-bolts and put the cap back on.
New oil, and after repeating the restart procedure (hard start, but with full choke she roared to life again, without any signs of trouble or incontinence.

I let the bike sit at idle for a few minutes while carefully checking things and looking for problems, but could not find any.
I tried revving, but the bike would surge and die. The idle wandered upwards as the bike warmed up, and ended up around 3-4000 rpm. I checked the idler screw and the cables but nothing out of the ordinary there, so i turned the bike off again and investigated more.

Turns out two of the carburetor boots are damaged, so i guess it's inhaling air where it should not. As far as i can tell, this matches the symptoms (hard start, starts with only full choke, dies when trying to rev). I will try glueing the boots, but if these are not salvageable, does anyone know the part number for these babies?
They seem to be different for the two left and the two right units.


Are these the correct model? https://www.suzukiperformancespares.co.uk/product/suzuki-gsx750-es-ef-84-88/5618/
Are there non-original parts of decent quality for a project on a budget?

Cheers, Carl

Edited October 6, 2021 by carl_87

[Dezza]

Do you mean that the oil filter cover was loose so when you started the engine it popped out and dumped oil on the floor?

 

For carb rubbers, use the French website used by Joseph on here. It seems to sell OEM carb rubbers for sensible prices, unlike UK suppliers. Try a recent search as the link was posted not long back.

[carl_87]

4 minutes ago, Dezza said:

Do you mean that the oil filter cover was loose so when you started the engine it popped out and dumped oil on the floor?

 

For carb rubbers, use the French website used by Joseph on here. It seems to sell OEM carb rubbers for sensible prices, unlike UK suppliers. Try a recent search as the link was posted not long back.

The nuts were tightened, but the grooves were so damaged that they were not holding on as well as they should. When the pressure rose in the engine and the cap put pressure on the nuts, the nuts slid on the damaged grooves and and the cover popped loose. Only a couple of millimeters but that was all it took.
Now it seems fine, though, after my mods!

Thanks for the tip, i'll look for the French site!
 

[Dezza]

It's this one.

 

https://www.xexpress.fr/marque-suzuki.html

 

Details in here.

 

 

Edited October 6, 2021 by Dezza

[carl_87]

Thank you Dezza, i'll be sure to check it out!

[carl_87]

Hmmm..

[Swiss Toni]

And don’t be tempted to leave the ‘bolts’ in the oil filter cover. Get the proper studs/domed nuts. Otherwise you’ll eventually wear the alloy threads in the cases out. 

[Gixer1460]

22 hours ago, carl_87 said:

The nuts were tightened, but the grooves were so damaged that they were not holding on as well as they should. When the pressure rose in the engine and the cap put pressure on the nuts, the nuts slid on the damaged grooves and and the cover popped loose. 

As these engines don't generate massive oil pressure, the fact that it cracked open at all would indicate the threads in the case are fubar'd! The bolts you are using are likely just catching the remaining threads at the bottom of the holes - this isn't a sustainable situation. It would be better to remove the exhaust and install some helicoils or Timeserts and add some stainless studs back in with ideally the correct domed nuts as Swiss Toni has noted above - they do get frequent use changing oil and filter every 3,000 miles / yearly.

[PanzerWomble]

Re inlet rubbers - these are cheap 

 

https://www.cruzinimage.net/2018/11/06/1983-suzuki-gs750e-intake-set-insulator-4-intakes-boots-included/

 

[carl_87]

Thank you fellas.
I'll see about getting the oil cap studs replaced, and thanks for the help with links to the inlet rubbers. I epoxi'ed the existing ones as a temporary solution to be able to continue with the fault finding to see if there is anything else amiss with the engine before i start ordering parts. I put them back on the bike and started her up again, but again hard start and full choke needed. Bike would die right away if i let off the choke.
I touched the exhaust headers and number 4 was cold while the others were all about the same temp. Did not remember to check if plug was wet.

This morning i checked number 4 for spark, and there was, it looked to be about the equal power in the spark as number 3.
I did a compression test that was quite disconcerting;

Engine cold, cylinder no:
1 - 100 psi
2- 140 psi
3- 110 psi
4- 85 psi

I'll try a wet compression test this afternoon (squirting oil in the cylinders) to see if the readings change. If they do change, this would indicate piston rings, correct?
And lack of change would indicate something else, possibly valves?

Edited October 8, 2021 by carl_87

[Gixer1460]

The fact it runs, although badly, would indicate the valves are working satisfactorily - if the engine HAS sat for 24 years then there is a strong possibility that the rings are stuck on the pistons allowing for the piss poor compression results. Sometimes soaking with diesel will free them off and running helps but I think with those results it is going to be a top end strip, clean and rebuild ! Oil in the cylinders may indeed improve the numbers - maybe up to spec. minimums! #4 deffo has problems if it won't even run!

[PanzerWomble]

I'd be tempted just to run it . Don't throw money at it until you know its a goodun ,

Get the cylinders nice and hot on a good long run , and the rings will come around . Some diesel or ATF will help loosen them up as GIXER1460  said . 

By your first post this is your first bike , get it running , sort the brakes and then do it up as you go along . If you strip it down ..chances are it will never go back together. 

& if you want advice about barn finds watch Vice Grip Garage on Youtube !

Edited October 8, 2021 by PanzerWomble

[carl_87]

An update from today,
Changed the brake fluid in the rear brake, old fluid was greyish and a bit opaque.

I put oil in the number 4 cylinder and did a compression test. I probably put too much oil in, because the readings were off the scale and i could not hold down the rubber tip of my gague hard enough to prevent a fine oil mist from spraying past the tip (the threaded spark plug adapters that came with the tester did not fit so i had to use the backup) . I let it sit for a while, then turned the engine over a few times, put the spark plug back in and started her up. (Still only starts with full choke and needs a lot of choke not to die in the first 5 minutes or so).
I immediately got a cloud of oily smoke out the exhaust and thought to myself "there shouldn't be oily smoke from number 4 if there was no combustion going on there"
Lo and behold, i could now feel heat on the number 4 header, this one had been cold before while the others were hot.

So i took her for a ride, my first ride! and the bike's first since 1997.

We r out cruisin', first time

I cruised around for a while. Could not get it to rev over 3-4000 rpm, if i opened the throttles wide open the bike would just stall. If i let back on the throttle to around 2000rpm, it would run again.

I went back home and let the bike sit while i did other things. Went back later, tried the starter, and *clack*. This bike is a learning experience, i have now seen firsthand how a hydrolocked cylinder manifests itself. Turns out number 3 carburetor must be sticking, so that cylinder was full of fuel.
Side note, the vacuum operated fuel thingamajig on the tank does not seem to work, so i have had the fuel valve in the PRI-mode that supposedly bypasses the vacuum mode.
Note to myself to not leave the bike in PRI before i have sorted this out.
Sorted out the hydrolock business, then i took another ride.

Now for the good news! I ran the bike around 20 minutes today. It did not run excellent, but it ran on all four cylinders.
I let the bike sit for an hour or so and then i redid the compression test (the engine has had around 20 minutes of runtime after i squirted oil in the cylinder for the wet test in the morning). It was now lukewarm but not hot to the touch.

Cylinder number - new/old reading:
1-145psi (100 psi) 
2-143psi (140 psi)
3-144psi (110 psi)
4-155psi (85 psi) <-Wow!

So things seem to be looking up compression-wise, i'll do a new test tomorrow with a cold engine.

Problems: hard start, needs full choke, does not rev past 3-4000 rpm. Number 3 is leaking fuel into the engine.
Im not afraid to take the carburetors aparts but if anyone has any tips on an area i should specifically focus on, i'm all ears!

And yes PanzerWomble, i'm really reminding myself of your advice to get it running properly before i start stripping things down too much! That's good advice!

[TonyGee]

compresion test is a lot better,  your carbs need a good clean, pay extra attention to the float needle valve as it sounds like its leaking.  and maybe a new air filter. 

[carl_87]

42 minutes ago, TonyGee said:

compresion test is a lot better,  your carbs need a good clean, pay extra attention to the float needle valve as it sounds like its leaking.  and maybe a new air filter. 

Thanks. For convenience while fault-finding i'm currently running completely without an airbox. Does this have any negative side effects on the carburetors operation, besides the obvious downside of running unfiltered air?