GT550 Oil Pump Question

[Syd]

Can anyone advise what speed you could test run the oil pump using a drill to test both the pump and check valves operating and also what direction is the rotation when looking at the shaft - I assume clockwise? Thanks

[yeadon_m]

Syd,

It will be obvious as to direction but also think its clockwise as viewed from below. Prime the pump and hold the lever and you will see oil as soon as one or two turns.

I think you'd drive it no faster than 60 rpm. I think it turns at a max of 30 rpm in the motor as its very geared down. You won't need to turn it fast to check its working ie more oil from three holes as you open the lever, and pretty much from three only (crank) with the lever closed. The cylinders get very little oil at idle but ramps up a lot. The crank gets a bit more at idle but it hardly changes with the lever.

In addition to pump checking, you might consider also testing the lines, as sometimes one banjo valve has a higher cracking pressure than the others in a 'trio' and results in relative redirection to the others in the trio. I've certainly seen that. Bolt the pump with O-rings underneath to the line, and use heavy copper wire looped through the pump shaft hole to turn with a battery drill.

Cheers,
Mike

[Syd]

Thanks for the info Mike. The problem I have is I brought a set of six new check valves from 1970sjapmotorbikeparts.co.uk and fitted these to the original oil lines which was not a problem, however when I filled the lines with oil and hang them up, all the check valves leaked badly and the lines emptied in a couple of hours - some in 30 minutes. I contacted the supplier of the valves and he said that I need to run the check valves first so that the seats & balls bed in hence my question about running the oil pump. I would be interested to hear from anyone else who has also fitted these new remanufactured check valves to see how they got on?

No problem to assemble everything and set this up on the bench with a drill as I need to solve this problem asap. Not sure how long to run oil through the pump and the check valves, say 20-30 minutes of so? I will let you know how it goes. Cheers Syd.

[barney01]

Syd have a look here lots of info on your problem.
http://www.suzuki2strokes.com/forum/vie ... ki#p158121

[Syd]

Thanks for the additional info. The supplier of the check valves also advised me today;

"The valves need to be fitted and the engine started to seal up the valves, as I''m sure know the check valves close under pressure in the crank cases to stop the oil being pushed back towards the oil pump and it this back pressure that seals the valves, when the engine is started the valves will open and close thousands of times in a few minutes and this action is what seals the valves fully"

At the end of the day, I have to try to get this sorted as I don't want to remove the 6 valves at the risk of damaging the oil lines. I was lucky that the new valves fitted ok. I will make up a small rig with a container so that I can provide 3-4 psi back pressure to all the check valves with air so the valves can work like they normally do to see if they settle down and form a seal a stop the leaking. To be honest, if I had know all of this, I don't think I would have gone this way, however hopefully, this will help sort the problem - I will get back to you with an update

[wents75]

Hi
This may be the wrong way to check the check valves but when you suck (yes banjo in your mouth ) they are naturely closed but open easily
When you blow they close immediately. Check or non return valves are as simple as that.
Dont think new ones should leak mate.

[Syd]

I made up a test rig (see attached pic) and used a battery drill to run the oil pump at low speed and all the new c/valves operate fine. The flow rate seems even as you move the oil valve lever over the operating range. I ran the new c/valves for a 10-12 min period and then left them sitting over night with a positive head above the pump of approx 200mm from a small oil container, however all six check valves still leaked. The ball and seats have seated in a bit after running 10-12 mins as they don't leak as bad compared to when I first fitted the new valves to the oil lines then filled them with oil and left them hanging as all 6 lines check valves leaked and drained the lines in a couple of hours.

I am making up some new fittings with plastic tubes to connect to each of the check valve banjos which will get low back pressure from a pressure reducing air valve of approx 1-2 psi while oil pump runs to see if this improves the ball/seat sealing on each check valve as I need to get this sorted. To be honest, I not happy about buying these new remanufactured copy Suzuki GT check valves only to find that they are prone to leaking.

[yeadon_m]

Syd,

It is annoying if the valves leak at rest but providing the leak rate is low, then given your lines are delivering evenly, there should be no lube issues and you can relax. The worst that happens if one valve leaks badly is that one cylinder will be smokier.

Cheers,
Mike

[Syd]

Hi Mike - My main concern would be oil leaking into the crankcase and possible hydraulic problems if all 6 valves slowly leak over time with the bike sitting around not being used or is this not such a problem with having Sris valves fitted?

[barney01]

Syd have you considered one of these if you are not using the bike regularly ?
http://www.suzygtparts.com/index.php?ro ... uct_id=265