Priming GSX 750 Oil system

[Seven50]

Hello,

I have looked through the forum and cannot find any info on this (which may mean it isn't an issue as no one has asked!, that or I cant use the search properly....)

I have a 1988 GSX 750 es which has stood for 25 years. As part of recommissioning I have got to the stage where I can crank it and have cracked the oil lines feeding the back of the head to see if the oil system is priming up. 

After cranking with the plugs out to get a good crank speed there is no oil appearing at this point on the engine. I have found an online service manual download but part of section 1 and 2 is missing (the service info)

Does this engine require the oil pump to be pre-primed or packed with vaseline? (after such a long time stood it is invariably empty and so may not self prime?

I am after some ideas on the above and if some one has a PDF of the manual which includes all of chapter 1 and chapter 2

 

Note to give an insight to the engine -  I drained the old oil - looked clean, no obvious wear metals, no water or sediments drained out (I have not had the sump off to inspect the strainer)

Replaced the old filter - again all intact (pleats all present and correct) housing looked clean, no water or sediments

Top end was immaculate with no corrosion or lacquering on components

Bores visually appear in good condition with no static ring marks from being stood. 

 

Any help / ideas are appreciated 

Edited December 9, 2019 by Seven50
missing info

[Gixer1460]

Did you fill the new oil filter - not actually necessary on a recently running bike  but would present an 'airlock' on one that has been sitting? The GSXR has two independent oil systems driven by a single pump - the one you've disconnected the hoses from is low pressure / high volume oil coolant system. The other is high pressure / lower volume for bearings - crank, rods, cams and gearbox. Easiest access point for this is RHS of engine under the ign. pick-up cover - engine main gallery so will be fairly obvious if now or low oil pressure LOL! PDF's of the Suzuki Workshop manual are around on the net - they are big files -230Mb from memory! You could try backfilling the pump with heavier wt. oil - 20w/50 should be sufficient - fill oil lines and rotate engine backwards via the rotor - one crank turn sufficient.

[Seven50]

Gixer1460 - Thanks for the input.

When I changed the oil filter, I noted a plug on the cover for the housing about 2/3 of the way up the casting. I put oil in through this hole thinking the same  - why put a bung there unless you need to pre-fill. So as the filter is post pump (normally is so assuming on this case) i thought it should reduce priming time. 

You reckon rotating the motor backward could draw some of this oil back into the pump? 

I have noticed a bung on the engine casing on the RHS which I assumed was the end of the main gallery - will take a picture tonight and post it to confirm. 

[Seven50]

so for anyone who picks this thread up I have some conclusions. 

If you get a bike which has been stood for a very long period of time, in this case 25 years, and the oil level has steadily dropped (when I purchased this bike it was just below the minimum, so below the strainer) the chances are you will have to prime the oil pump. 

I have removed the sump and investigated and the oil  pump is bone dry. Now as there is no debris, wear metals or sign of distress in the bottom end I will assume the pump has been turning when cranking. As such if one of these pumps does dry out it will not self prime (makes sense)

Solutions - in my case I have removed the sump, but i think  having looked at the design of the oil circuit in the sump, I could have gotten away with pumping oil in though the oil cooler inlet pipe so outlet from the sump (right hand side of the sump when sat on the bike). In my case I will pump a heavy weight oil (such as gear oil) into the pump (somehow ) and then reassemble .

I will report if I have success. 

[Gixer1460]

On 12/9/2019 at 12:13 PM, Seven50 said:

Gixer1460 - Thanks for the input.

When I changed the oil filter, I noted a plug on the cover for the housing about 2/3 of the way up the casting. I put oil in through this hole thinking the same  - why put a bung there unless you need to pre-fill. So as the filter is post pump (normally is so assuming on this case) i thought it should reduce priming time. 

You reckon rotating the motor backward could draw some of this oil back into the pump? 

I have noticed a bung on the engine casing on the RHS which I assumed was the end of the main gallery - will take a picture tonight and post it to confirm. 

The bung is there to close off the gallery after all the machining operations in the factory, a lot of peeps, me included. use that gallery for turbo oil supplies.

[johnr]

long shot, but if its a 750 engine, make sure that someone hasnt robbed the oil pump gears to fit to an 1100!. theyre behind the clutch basket.