Unleaded fuel

[Lasermatrix]

Hi All,

Since my local garage is soon to stop selling LRP and I can't find another garage that sells it, whats the best method to fuel my Merc 70hp Blueband?

I'm guessing the best option is to use unleaded with an additive?

Also, can someone confirm the correct oil mix ratio for this engine? Is it 50:1?

The reason I ask, is it seems to smoke a lot at that ratio.

Regards
Chris

[Searider]

Originally Posted by Lasermatrix

Hi All,

Since my local garage is soon to stop selling LRP and I can't find another garage that sells it, whats the best method to fuel my Merc 70hp Blueband?

I'm guessing the best option is to use unleaded with an additive?

Also, can someone confirm the correct oil mix ratio for this engine? Is it 50:1?

The reason I ask, is it seems to smoke a lot at that ratio.

Regards
Chris

Hi,

50:1 is correct.

Regarding unleaded petrol, i believe that all outboards can use it. They have the oil for lubrication and Leaded petrol has been unavailable in the USA for about 25 - 30 years.

However, best check in your owners manual or with a mercury dealer (or Barrus) to be sure before unwittingly trashing your engine on my account!

[Lasermatrix]

Originally Posted by Searider

Hi,

50:1 is correct.

Regarding unleaded petrol, i believe that all outboards can use it. They have the oil for lubrication and Leaded petrol has been unavailable in the USA for about 25 - 30 years.

However, best check in your owners manual or with a mercury dealer (or Barrus) to be sure before unwittingly trashing your engine on my account!

Thanks SeaRider

I just noticed that on another post, I will check with a Mercury Dealer first tho, just to be safe

[Cookee]

Absolutely correct - all 2 strokes can use unleaded, and all of the newer 4 strokes will be set up to use unleaded as well. With the newer HPDI 2 strokes and the Verados with supercharging, you might see improved performance with better quality fuel such as super unleaded. Older 2 strokes will be fine on regular unleaded though!

[Mr-d]

Erm... Does this mean the engine was designed to run on leaded fuel in the first place?

I've been running mine on Unleaded since i got it.... what would happen if i added lead replacement? would the engine be happier and run smoother?

[Cookee]

Originally Posted by Mr-d

Erm... Does this mean the engine was designed to run on leaded fuel in the first place?

I've been running mine on Unleaded since i got it.... what would happen if i added lead replacement? would the engine be happier and run smoother?

It means that 2 strokes don't need lead at all. Adding lead replacement would have no effect - if you want the engine to run smoother try Optimax or super unleaded back to back with regular unleaded and see if you can notive the differance, otherwise save your money!

[lc0021]

as far as I know, lead was added to the petrol to prevent 'pinging' (pre-ignition) in "higher" compression engines - I think traditionally 2 strokes have lower compression ratios than 4 strokes (except perhaps in the case of extreeeemely high performance 2 stroke engines... ) so generally they are less sensitive about running on unleaded...

In addition - again - as far as I know - it is usually the valves which suffer damage when you use unleaded in an engine which hasn't been designed/set up for it... however - one of the beauties of the 2 stroke is the lack of valves - so in this case they cant get damaged!!!

[pellesmil]

Lead was added to petrol to lube the the inlet and exhous valves (where valve seats) and to prevent the exhous valve from burning up.
Since 1980,s (when lead was banned) the materials have improved and will take the strain whitout eny extra addetive (this goes for 4 stroke) since 2 stroke is oiled in gas and dont uses valves it dont require lead
Lead may have had an influence on performance, but it,s mainly the octane that gives y more power.

Try different (better) oil, to reduce smoke