Manual oil pump problems

[Spud99]

Hi all, I have just got a 6m rib with 135hp mercury 2 stroke (1996). Short version is i think the oil pump is not pumping oil into the fuel. I have boat back out of the water and running on a small premixed tank. There appears to be no oil from pump. I split pump and all looks ok. I cant get the shaft from the drive the the pump out, looks like i would have to do a lot of ripping for this. There is very little to the pump really. I don't have the buzz at key on either but this is probably the alarm module/broken wire. This as far as i can tell should not stop oil. All i can find is people bypassing the pump and running on premix. I don't want to go down this route. I like to keep everything as close to original as possible. Any suggestions welcome.

[paintman]

The buzzer not working won't affect oil delivery.
The oil drips out of the pump & into the fuel line before the carbs. Don't expect to see oil squirting out of the pump delivery as it isn't under high pressure.
If there is oil in the top tank - the one on top of the engine - then it should feed to the pump.

The top tank is fed from the main tank in the boat which is pressurised from the crank case. Follow the lines from this tank & you'll see where it goes.

How have you established that it isn't delivering oil?
Try removing the oil pipe at the 'T' junction with the fuel line, plug the fuel line & start on premix to see if oil comes out of the oil pipe.

The usual advice is to remove the lot, fit the blanking kit - the long plastic plug is to prevent a bush coming loose inside the engine - & run on 50:1 premix.
I don't recall seeing any where it has been recommended to keep this system but plenty where it has been claimed to have totalled the engine.

Seen one post where the owner connected a pipe as a loop from the pump outlet to the pump inlet. Filled said pipe with oil to lubricate whatever the oil would normally lubricate & runs on premix. There were no subsequent posts as to how well this had worked though!

I recently had to replace the small tank cap on mine - top split on the old one - & seriously considered converting as the cap was just over £100 so I suspect I've viewed all the same threads on the various forums that you have.

Have a look at this thread from some years ago. The same pipe on my Black Max 135 split in much the same place as on his one.
I only saw it out at sea when I was drifting (fishing) & wondered where the oil slick at the back of the boat was coming from!
https://www.rib.net/forum/f36/80s-me...elp-57406.html

[Spud99]

Hi Paintman, thanks for reply. Yes i have seen most of the videos you mentioned, and i had seen your post. I have checked all pipes and all look sound. I had run from the premix tank for about 15 min with the pipe from oil pump off (i disconnected it at the brass fitting (check valve) half way down the output of pump) nothing came out bar a drip in that time. this was probably due to the vibration.The long story why i know it is not getting oil is after the day i launched, as soon as i went to throttle it, the boat cut out, to me what was happening was no oil in mix, and when engine was heating up she was starting to stick. I was able to anchor and get ashore and got an old tank and premixed it (i went 40:1 to give her a fighting chance) this got me back to slip and recovery.

I really dont want to go premixing and bypass pump.

I will have a look at the main tank to holding tank pipes as you suggest.
Thanks again

[paintman]

Is there oil in the top tank? Manual says this tankful will last for around 30 mins at full throttle.
This will gravity feed to the pump.

Quick look at the manual to check the pump drive system says:
1. Use a 50:1 gas and oil mixture and start the engine. Be sure engine has proper cooling water
2. Disconnect link rod connected between oil injection pump and carburettor linkage.
3. Disconnect outlet hose of oil injection pump and observe if injection pump is pumping oil. If pump is not pumping oil, the drive system to the pump is faulty.

Did you find this?:https://continuouswave.com/whaler/re...Injection.html


TBH whilst I also do prefer to keep things as original if mine plays up I'll be going the premix route.

One of the vids I saw showed this being done & the drive shaft came out without difficulty although I suspect you'll need to turn it as the meshing gears on the shaft & the drive collar on the crankshaft are angled not straight cut.
ETA. Found it. On a jetdrive powerhead.

https://www.youtube.com/watch?v=Fqad5gpaCJM

Looking at the manual replacing the drive collar means a big tear down with all the fun that trying to remove the various corroded in bolts will entail!

[Spud99]

Thanks again Paintman, I got time again today to look, All my pipe work is sound. The reservoir is getting filled from remote tank (The alarm is not working tho, so module must be gone). I tried again to remove the shaft from the drive like the video you posted, but it will not come out. The pump itself is ok. stuck the drill on the end and she pumps away. So by process of elimination I'm saying problem is inside at the drive.

As much as it pains me, I'm not going to rip engine apart at the moment. I will just premix in the main tank and run from there. I left the coupling from the drive to pump off, and will just leave the pump the way it is for now. with this i feel like I'm
thanks for your help

[paintman]

Annoying but when they're running they're not a bad engine.
Might be a bit smokey - certainly mine on first start for the day makes it's presence known esp if there's not a lot of wind in the harbour.
Think the Naval term is 'Make smoke'!