Yamaha TRX850 Enthusiasts Forum

If not' will it work?

From memory the TRX oil pressure is not very high, those brake pressure switches activate WITH pressure, you need a sender / switch that operates without pressure or as the `base` pressure setting for the switch / sender in the oil gallery is lost.
I have Eisi`s switch and coupling but am yet to fit it. I`m thinking of using the coupling supplied to take off an oil line to a guage, (digital or analogue) so that when you see a drop in pressure you can act more quickly than if you just see a bulb light when the pressure has dropped below a certain threshold.
SPA do a lovely oil pressure and temperature digital guage but like anything good it ain`t cheap:

http://www.spa-uk.co.uk/design/productd ... ?objid=130

There WILL be similar, maybe cheaper versions around, it`s just a matter of finding them.

Mincehead wrote:From memory the TRX oil pressure is not very high, those brake pressure switches activate WITH pressure, you need a sender / switch that operates without pressure or as the `base` pressure setting for the switch / sender in the oil gallery is lost.
I have Eisi`s switch and coupling but am yet to fit it. I`m thinking of using the coupling supplied to take off an oil line to a guage, (digital or analogue) so that when you see a drop in pressure you can act more quickly than if you just see a bulb light when the pressure has dropped below a certain threshold.

So what you are saying is... "someone has tried it and it didnt work"?

I do understand the difference in pressure between the 2 circuits, just wondering... It would be soooo cheap and easy.

It`s not going to work Hugo, it makes a circuit WITH pressure, you need something that makes a circuit without or at a lower pressure than would be found in the oil gallery.
Here`s a cheap little Harley number I`ve just found with a quick search:

http://cgi.ebay.com/ebaymotors/NOS-OIL- ... ccessories

And a tiny digital version, again made for Harleys:

http://cgi.ebay.com/ebaymotors/HD-Harle ... ccessories

Ok ok ok ok ok ... I now see where the issue resides and I do appologise because "English is not my mother's language"

With use of a normal 4 or 5 pin relay you can easily make a "ON-WITH-PRESSURE" switch go to "OFF-WHITh-PRESSURE" switch. Do you see what I mean? If not I can always draw something tomorrow and post it here.

My only doubt here is: Will there be enough pressure in the engine to actuate the switch?

Ahaaaa yes that switching relay would work. I`ll have to find that oil pressure light thread, it`ll be here somewhere. Meantime you could try contacting Goodrich to see what pressure those switches operate at.
That was easy, you`ll find the oil pressure spoken of in this thread somewhere:

http://trx850.motomaniac.net/forum/view ... ght#p58905

The switch is rated at operating between 0.15 and 0.35 bar from that thread above.

I've got a few of these bolts in the shop but I'm unsure about the thread. They might be 3/8 once they were bought for Harley master cylinders and calipers.

Sometimes the cheap Asian custom crap comes in mm and we have to use metric banjo bolts. I'll run some testing in the morning and post results.


INFO:

"Here are the parts needed:

- banjo bolt M10x1.25
- oilpressure switch VW-Bus T2/T3 (0.15-035 bar, at the highest point since I Siphon - but it is also 0.3-0.6 bar)
- lamp from Yamaha Cockpit"

Hmmmm reading through that thread again it seems the switch goes OPEN contact at the correct oil pressure meaning the light goes out.
I thought it would make the light come on if the oil pressure dropped but either way a bulb is simply an indicator of the state of the oil pressure whichever way it works.
In fact now I think about it ALL systems I`m familier with light up when low oil pressure occurs, cars especially are set up this way.

No joy in finding the right bolt with the right thread. To test this, I would have to buy the right bolt.

i'll think about it...

Try connecting a piece of tubing to the switch (snug fit) and utilising one of those small hand pumps you can get for pumping up suspension or tyres. If it`s got a guage on it you should be able to light a bulb etc and see the pressure it operates at.

BRAINSTORMING!!!!

may i ask what the advantage of knowing your oil pressure is?

Or is it more a case of incase something goes wrong inside the engine?

If you can monitor your oil pressure you can react if it drops. I.e cutting your engine immediately so as to lessen damage to internal components and bearing faces.
Often if you have an oil pressure guage you can see when wear and tear is affecting your engine, oil pressure drops off when the motor is up to operating temperature indicating worn bearing surfaces or an oil pump being worn, even an oil leak you may not know about.
Think of a tube with oil flowing through it, if you increase the internal diameter of the tube but do not increase the volume of oil being pumped through that tube the pressure will drop.

Cheers, I'll just make sure mines working properly instead haha