Jump to content

oil injection vs premix


fishon

Recommended Posts

hi guys recently purchased a 40hp mercury lightning xr with oil injection

and a bit worried that if the oil injection fails least with premix its a fail safe way (if you remeber to add it that is )

but im sorta thinkin to why would the manufacturer add the injection if it wasnt good

just wandering what are other peoples thoughts and if anyone else has had a problem with oil injection

cheers

Link to comment
Share on other sites

mate i have a 60hp mercury oil injected outboard and about 3 years ago the oil line disentgrated while i was boating and as a result i gouged out the pistons. Luckly the brother is a mechanic so we could repair the problem though it did still set me back a grand for new pistons and machining the head etc. If i had premixed some oil in the fuel maybe it would have prevented the extent of damage, though i guess if you regularly maintain your motor and have it serviced then hopefully any problems will be picked up before they occur.

Link to comment
Share on other sites

The oil injection comes down to a personal preference

The injection system in great in theory it means you can run straight unleaded without the hassle of premixing

The downside is that if the injection side fails often you will have no warning and you will do serious damage even if it is run for short times.

You will hear people complain of the system being at fault but at the same time if they are correctly maintained you will limit any potential isses perhaps have all of the seals and pump replaced at regular intervals.

I have helped work on 2 oil injection motors 1 yamaha and one Johnson both failed due to poor maintainance the seals in 1 and the oil lines in the other

Your fuel system would fail in the same way if it also was not maintined correctly

dont be scared off oil injection make your own decision and keep it well maintained if you do go with it

cheers

Link to comment
Share on other sites

tumra - i double that. Same thing happened on my motor, oil injection blocked, alarm didnt work and bang, engine buggered up.

Luckily i found a good hands on mechanic and got me back on the water asap, but cost me some $$$, but i must say it wasnt as bad as i expected with cost and engines looks like new.

Now i have a new sensor for the alar, brand new looking and feeling engine, but now premix and use injection as well.

Link to comment
Share on other sites

tumra - i double that. Same thing happened on my motor, oil injection blocked, alarm didnt work and bang, engine buggered up.

Luckily i found a good hands on mechanic and got me back on the water asap, but cost me some $$$, but i must say it wasnt as bad as i expected with cost and engines looks like new.

Now i have a new sensor for the alar, brand new looking and feeling engine, but now premix and use injection as well.

what you premix your fuel and use oil injection have you had any dramas with over oiling?

Link to comment
Share on other sites

As long as your alarms are working then you will always know if your oil level falls low and you are at risk, and on the flip side, if you have your outboard regularly serviced by a mechanic you should be protected against failure of the oil injection system.

I don't know for sure, but do any marine insurance policies protect you against failure of components which result in engine failure?

Link to comment
Share on other sites

tumra / fishon - when rebuild was done, i ran oil injection and 50:1 in the fuel mix.

after 20 hours, still applying the above i changed spark plugs. Didnt have to but i did.

Only downfal over oiling is you get that carby smoke puff when you start it, and obviously a little more smoke.

But never had an issue.

Now i will probably just go back to oil injection now that i know it is fixed, but i dont believe it will cause an issue with too much oil.

Nick F - a mechanic cannot really determine an alarm sender/sensor failure as the sensor is inside the oil bottle at the bottom. Remeber the electronics can fail / corrode. Best bet is make sure after each trip oil level drops with fuel consumption.

When my oil failed, and bare this in mind if you are out on the water and this happens, my engine shut itself down straight away. Because my oil light was not on (as it was broken) i thought it just stauled it as i was travelling under 1500rpms. Then once i re started it i gove it a bit to get going, and again it stauled. I started it again and moved on then within 300m engine blew a cylinder. If i had of thought hard the first time as to why it stauled, and checked oil, i woulda saved the engine.

But in saying that mechanic found a handful of faults in the engine that would have come to surface in the future.

Now i have brand new compnents, new oil sender, oil bottle, alarms, sensors, carby. Brand new engine and i get 8km more speed. :)

Link to comment
Share on other sites

with adding oil to both fuel and injection tanks the only downside i can see is when you are trawling and going under 4 knots alot of smoke and chance of fowling plugs.also you can test sensors with a ohm meter.cheers dunc333

Link to comment
Share on other sites

When my oil failed, and bare this in mind if you are out on the water and this happens, my engine shut itself down straight away. Because my oil light was not on (as it was broken) i thought it just stauled it as i was travelling under 1500rpms. Then once i re started it i gove it a bit to get going, and again it stauled. I started it again and moved on then within 300m engine blew a cylinder. If i had of thought hard the first time as to why it stauled, and checked oil, i woulda saved the engine.

mate if only i read this post 3 years ago... the same thing happened to me also. The engine kept on stalling untill i gouged the pistons and the engine would no longer start. i hope this will make others aware if it ever happens to them.

Link to comment
Share on other sites

yeah i spoke with penrith marine earlier he reckons dont do away with the oil injection as its a mechanical pump he reckons hes only ever seen 1 come back with a genuine faulty pump( 40hp lightning xr ) he reckons there definately a good thing on that particular motor but reckons if im that worried run the injection and premix with 100;1

reckons it will be fine and that i definately got a good motor

so im very happy chappy now

thanks for all your replies fellas much appreciated

Link to comment
Share on other sites

i only ever pre mix it myself people say its a pain but its simple calculate tank size work out how much oil buy a measuring cup to suit oil size, mark it so u just add whatever amount u need pour it in the tank go to servo fill up and go fishing, easy. and no problems my mate who is a marine mechanic does the same he swears by it not worth the risk for 2minutes extra work,

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...