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Testing oil pressure

Started by manofthefield, August 17, 2004, 05:10:41 PM

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manofthefield

I'm planning on testing my oil pressure this weekend and I need to know what pressure it should be at at idle on a warm bike.  I know it should be between 28 and 71 psi at 3000 rpms, per the Clymer.  But I would like to check at idle(12-1500rpms), as that is the speed I had problems earlier(see my old post).

I think my problem was oil degredation.  My problem happened after about 1000miles with plain 10W40 oil.  New oil - no problem.  Another 1000 miles, same problem.  So this time I'm trying Mobil Devlac, hopefully it won't break down as fast, so far so good.  A mechanic claims I need mc oil, but i don't beleive in that stuff.  I just have the opportunity to check the pressure while I'm at home, so I want to do it while I can.
motorcycleless
1998 GS500E sold 6/20/11

mp183

I use Castrol GTX and change it every 3,500 miles in both of my bikes.  Can't see oil getting destoyed to the extent that it will cause short term problems.
2002 GS500
2004 V-Strom 650 
is it time to check the valves?
2004 KLR250.

cernunos

Since oil pressure tends to be linear with RPM in plain-bearing engines with full-flow, relief type oiling systems I would think that pressure should be approximately 10-15 PSI/1KRPM thereabouts. Did you ever check the sending unit and wiring from that previous problem? And I'm wondering what exactly you mean by "degradation" of the oil. GS500...pretty cool bike...GStwin forum, seems ok.

C.......
Don't hurt, don't take, don't force
(Everybody should own an HD at least once)
(AMF bowling balls don't count)
Jake D for President 2008

cernunos

A really informative article on oils, although not MC specific it does give you some good general guidelines. www.bmcno.org/techtip_motor_oil.htm

C.......
Don't hurt, don't take, don't force
(Everybody should own an HD at least once)
(AMF bowling balls don't count)
Jake D for President 2008

manofthefield

I did not check the sending unit, gave a quick once over of the wires, but found nothing wrong, though I could have missed something.  

By degradation I mean breakdown/viscosity retention.  I was actually reading a few articles online, this one specifically about bikes was pretty interesting to me, even though it's a little old (skip to the very bottom table for the short version).   I thought this info might be associated with my problem.

Before everyone jumps to post it, I've already read this one a number of times http://www.yft.org/tex_vfr/tech/oil.htm
motorcycleless
1998 GS500E sold 6/20/11

cernunos

I'm interested in seeing the results of your oil pressure tests. Good luck...and you know what I say, so I won't say it.

C.......
Don't hurt, don't take, don't force
(Everybody should own an HD at least once)
(AMF bowling balls don't count)
Jake D for President 2008

manofthefield

I look forward to seeing my results too.  Anyone have experience testing the oil pressure on these bikes?  Srinath, did you say you have a gauge permanently mounted?

Next question: How would I go about testing the sending unit/oil sensor(I assume these are the same thing)?  Is it an open circuit until it is subject to a certain minimum pressure and then closes?  How do you test that?
motorcycleless
1998 GS500E sold 6/20/11

Kerry

Quote from: manofthefieldNext question: How would I go about testing the sending unit/oil sensor (I assume these are the same thing)?
Click to see what the Haynes manual says about the "Oil pressure switch".

Does that help?
Yellow 1999 GS500E
Kerry's Suzuki GS500 Page

manofthefield

Thanks Kerry :thumb:   Yes and No.  I was wondering what the Haynes had to say about this, and it is the exact topic I was looking for.   But I think my results will be inconclusive.  My light acts like it should, coming on with ignition on, not running, then going out shortly after the bike is started.  It never comes on except for those couple instances.  

I have to more carefully reread that page, and I will definately be doing those tests
motorcycleless
1998 GS500E sold 6/20/11

Kerry

Hmmm.  Well, while I'm at it, here's the other topic that may apply.  It doesn't seem like it will help much though.
    Oil Pressure Check[/list:u]BTW, the specs listed in the Haynes manual seem identical to yours:
      Oil pressure (with engine warm) . . . . 28 to 71 psi (2.0 to 4.0 bar) at 3000 rpm[/list:u]
      Yellow 1999 GS500E
      Kerry's Suzuki GS500 Page

      scratch

      I'm curious now. On my little 250, there was a bolt on the back of the cylinder that you would crack open to check and make sure that you were getting oil to the head after an oil change. I'm guessing it was tapped into one of the oil galleys supplying the head. I checked it a couple times and then never again, because I was confident that oil was getting to the head (evidenced by the copious amount of oil whenever I did a valve adjustment).

      I see bolts that are similarly placed on the back of our cylinders and wonder...but, since nothing is mentioned in the shop manual and I have plenty of oil, I have no real reason to check these bolts (not to mention the mess).

      These also might be good places to hook up a pressure guage.
      The motorcycle is no longer the hobby, the skill has become the hobby.

      Power does not compare to skill.  What good is power without the skill to use it?

      QuoteOriginally posted by Wintermute on BayAreaRidersForum.com
      good judgement trumps good skills every time.

      manofthefield

      Update:  I have just moved in at school, so my internet access is limited to whenever I get to the lab for a while.  Hopefully I can post some pics when I get cable at my apt and get some spare time.

      Haven't checked the pressure yet because I haven't got my hands on anything that will screw into the hole for testing.  I think I will be getting a tap and die set with the propper size die to modify the thread on a pipe fitting.  BTW, the hole is M14 x 1.25.  

      I strained the oil and I am finding little grey rubbery pieces.  I took them to a local mechanic and he said it looked like Yama-somethingorother (he was a mechanic at a yamaha dealer).  Translated, the Yama-whatchamacallit is a gasket maker that is usually used when bolting the engine halves together and a few other select spots where gaskets aren't used.  Usually some gets squished out, like whenever you use gasket maker or sealer; so the excess is breaking off and ending up in my oil.  I don't know if this is from when the engine was originally put together 9500 miles and 6 years ago, or if that means the engine was rebuilt before I bought it (no other signs of engine dismantlement, so doubtful).  

      Anyone else ever see little (1/8th to 1/2 inch), grey pieces of rubber type stuff in their oil?

      So now I believe my problem is the gasket maker stuff is breaking off and slightly blocking my oil passages or oil pickup every once in a while, which I can fix by revving the engine or moving the bike around.  Other than that I might keep changing my oil often to get all that crap out and I will eventually check my pressure and post my results.
      motorcycleless
      1998 GS500E sold 6/20/11

      Rema1000

      Yamabond?  Sometimes people use too much gasket goop when they put the valve cover back on.  Since valves need to be checked so often, it's often an owner that does it.  Owners have been known to use anything, including silicone caulk (and even shops have been known to use too much gasket goop).  You may want to check your valve clearance, and while you're at it, check for disintigrating goop around the valve cover gasket.  

      But 1/2-inch bits of gasket don't sound good at all!  I think you could have some clog-up a journal, and your pressure might still look good overall, but yet you may not get full oil circulation, which sounds bad.
      You cannot escape our master plan!

      Toner

      Guys the Hanyes manual says you need a couple of Suzuki items to do an oil pressure test and lists their part numbers as:

      suzuki 09115 74510
      suzuki 09915 77330

      One is the gauge and the other is an adapter to attach it.

      What are people using? I can't find these items anywhere.

      sledge

      The pressure testing kit I have includes a selection of adaptors, one of them fits the gs5 port. I think it's M14x1.25

      Try a local hydraulics specialist, they should be able to sort you out.

      Toner

      Quote from: sledge on July 13, 2018, 03:46:31 PM
      The pressure testing kit I have includes a selection of adaptors, one of them fits the gs5 port. I think it's M14x1.25

      Try a local hydraulics specialist, they should be able to sort you out.

      Don't think there are any hydraulics specialists local around here.
      Why do I need to search for on ebay?

      herennow

      Oil pressure gauges on eBay are cheap. I picked one up few years ago for under 50 bucks iirc . Works well.
      A couple of things, the sensor activates at a very low pressure. Much lower than the pressure required by the engine,it only really shows almost total loss of pressure.
      One thing that I have seen before is that there is a difference between the sump gasket of the original engine and the new water cooled engine. Swapping them can lead to low pressure as oil channels might not seal properly.
      Good luck!

      Kookas

      Quote from: herennow on July 15, 2018, 11:16:56 PMthe new water cooled engine.

      Slightly pedantic correction, but the newer engines are oil-cooled, rather than water-cooled.

      sledge

      Quote from: Toner on July 14, 2018, 10:49:43 AM
      Quote from: sledge on July 13, 2018, 03:46:31 PM
      The pressure testing kit I have includes a selection of adaptors, one of them fits the gs5 port. I think it's M14x1.25

      Try a local hydraulics specialist, they should be able to sort you out.

      Don't think there are any hydraulics specialists local around here.
      Why do I need to search for on ebay?

      You need to search for, or have something made up that will couple your gauge to the oil port (which I think) is M14x1.25. Problem is we don't know for sure what size the fittings are.

      If you were to take the guage, and the plug from the bike to a hydraulic specialist they could easily do this for you. Pirtek is the big name but there smaller independents who are far cheaper.

      gregjet

      The grunge in the oil. Haven't I seen a post here about the polymer cover on the alternator disintergrating and leaving stuff in the oil. Might be worth checking your stators.

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