Fuel Prices!

[craiglaforce]

The little bit of oil I add the the gas tank seems to reduce engine friction and make it run smoother, cooler and have faster pickup. There is still no visable smoke (other than the initial puff on startup) or slick of any kind and the plugs still look clean at the end of the season. I first did this when trying to troubleshoot my initial overheating problem. Actually I think that was more due to the extreme spark advance that had been set on the motor when I bought the boat. It was way more advanced than the manual specified. But the oil did help it run cooler. By a little bit I meant around 100:1 in the fuel tank to augment the VRO oil pump. I'm a little nervous that the motor manufacturers might have been arm twisted into running too low an oil injection rate to meet some emission spec. at the expense of slightly under-lubricating the motor. Not sure if this is the case on everyone's motor, but it made a pretty obvious improvement on mine.

Kinda like the difference you notice before and after changing the oil on your car. By the way, Castrol Syntec blend for cars is awesome stuff and still reasonably priced. For the boat I use quicksilver.

I've heard lots of opinions on Iboats.com about VRO pumps failing and damaging motors. Many on that board have removed the oil pumps and prefer to manually add the oil to reduce risk of oil pump falure.

[Max]

You lot don't know how lucky you are!!
British fuel prices 3.20 for US gallon = 3.20 x $1.80=$5.76 a gallon equivalent!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
And we've got North Sea Oil!!! (but a damn greedy government)
enjoy!
Max

[Don T]

Hello:
There is a lot more to disconnecting the oil injection pump than just mixing oil in the gas. The crank bearings are directly fed by the pump, first to the mains and then the rods via a slinger. You would have to remove the slinger at the very least in order to properly lubricate the main bearings. Oil injected motors have a lot longer bearing life than oil / gas mixed ones.

[Chip Hindes]

seems to reduce engine friction and make it run smoother, cooler and have faster pickup.

That is your imagination at work.

Excessive spark advance will cause overheating and may cause engine damage.

I'm a little nervous that the motor manufacturers might have been arm twisted into running too low an oil injection rate to meet some emission spec. at the expense of slightly under-lubricating the motor.

Tohatsus are legendary for their ability to run forever with little maintenance. They wouldn't risk ruining this reputation.

If your motor is truly underlubricated, you'll know before long, because it will self destruct.

Kinda like the difference you notice before and after changing the oil on your car.

Exactly. There is no difference. Either your imagination is getting the best of you or you're waiting far too long between oil changes.

I've heard lots of opinions on Iboats.com about VRO pumps failing and damaging motors. Many on that board have removed the oil pumps and prefer to manually add the oil to reduce risk of oil pump falure.

Don't believe everything you read on discussion boards This about the same as saying you should always rope start your motor to keep from depleting the batteries and wearing out the starter. People who do this are (to put it in proper context) not running on all three cylinders.

[Don T]

Hello:
Well, I can tell when my van's oil is changed. Mostly due to the contaminates like fuel and carbon that are no longer being sucked up by the PCV valve. Changes it's drivablility. Fuel injected vehicles will take around 40 miles of driving to compensate for the difference. Not imagination at all.

[craiglaforce]

Just to clarify, I certainly do not advocate removal of the VRO oil pump, but I do respect the opinions of the good mechanical folks on the iboats board (and this one also of course).

I agree about the ignition timing being too advanced and causing the overheating. Maybe I wasn't clear in my statement. That was the main problem.

I definitely can feel the difference on car engine performance with an oil change. (oil loses some of its lubricating qualities after a few thousand miles of heat and contamination, one of the reasons oil changes are needed other than the corrosive effects of the contaminants). And another big difference if going from normal oil to a partial or full synthetic.

I had one of those semi-hi performance dual overhead cam 4 valve per cylinder engines which had a huge amount of friction in it from all the extra moving parts. When I changed to a synthetic oil on it I picked up about 2 mpg and performance went from simply good to remarkable.

It even takes longer to warm the engine up in the winter because the friction is so markedy reduced with a synthetic.

I'm not saying all Tohatsus need more oil, I could easily have an underperforming oil pump. Thats why I was careful to limit my comments saying things like "on my engine it seemed to help."

But it is a little odd that the manual says to add oil to the gas tank for the first tank of the season. This seems to imply to me that they are cutting the oil pretty thin. Maybe not thin enough to damage the engine, but maybe enough to affect performance?

Please ignore my ramblings if you are happy with your setup.
I didn't mean to imply my way is any better than other ways.