To bypass oil injection or not to...bypassed!

[Blkrvrbart]

I’m nearing the end of my ten hour break in period on the new motor I installed. From the beginning of this project I’ve considered bypassing the oil injection system and running premix. For break in purposes, they prescribe running premix and injecting the oil through the system. It does smoke pretty heavy on startup until it’s warm, but not terrible. Is there any reason I should not delete the oil injection system and run premix 50:1? I hear a lot of folks saying delete it, and it seems like eliminating a big potential problem. Thanks for your opinions and input.

 

[Stomp10]

I have always felt that the oil injection is a potential weakness in the whole system. Failure can have catastrophic results.
If I ever get to that point..... mine will be bypassed as well.

My existing engine (that still runs) is bypassed and runs premix. So, my problem is how to get through break in minus the oil injection.
Haven't quite worked that out yet.

For the break in I would need to find oil tanks and whatnot, reinstall etc.

Anyone have any advice on this?

 

[Blkrvrbart]

I have always felt that the oil injection is a potential weakness in the whole system. Failure can have catastrophic results.
If I ever get to that point..... mine will be bypassed as well.

My existing engine (that still runs) is bypassed and runs premix. So, my problem is how to get through break in minus the oil injection.
Haven't quite worked that out yet.

For the break in I would need to find oil tanks and whatnot, reinstall etc.

Anyone have any advice on this?

Hey Stomp.
Even with the variable rate injection system I’ve questioned how, in a carbureted system, does that really make good sense to have a system that leans out the oil ratio while cruising, but then if I come down off plane to let another boat by and return to plane, the fuel in the carb bowls is not mixed for that condition, how is that better than premixed?
I am attaching a photo of the break in sheet sent with my engine. The instructions say to double your oil. So if you don’t have the injection system, mix the fuel at 25:1 instead of 50:1.

She’s gonna smoke, but that’s just the first ten hours.

 

[Stomp10]

Thanks, I did read through that a couple of weeks ago, appreciate that reminder.
It fell out of my head while I concentrate on planning out the swap.
One less thing to worry about now.

Even with the variable rate injection system I’ve questioned how, in a carbureted system, does that really make good sense to have a system that leans out the oil ratio while cruising, but then if I come down off plane to let another boat by and return to plane, the fuel in the carb bowls is not mixed for that condition, how is that better than premixed?

That's a good point too.
I've always run premix but I'm pretty old school. I have no problem doing it though.
Never had a 2 stroke blow up on me yet.....

Did you back your idle down for the first hour or just go with the 1000rpm?

 

[Kenneth Johnson]

Do you know how much smoke you may have with premix? I am preparing to reinstall the oil pumps to reduce the embarrasing smoke screen.

 

[Blkrvrbart]

@Stomp10 I kept my idle at about 900 for a while, now it’s set at 1100. Idles good, but I might turn it down some.
@Kenneth Johnson i premixed 40:1 and had the injection system mixing more, so mine was smoking pretty heavy at launch and warmup. I don’t think it can possibly smoke that much at 50:1.

 

[Blkrvrbart]

Finally found this. I knew I had seen this when searching for an engine. This is one of the reman supplier’s recommendations

 

[Blkrvrbart]

Done. It was about a two hour job and now a lot less can go wrong.

 

[Blkrvrbart]

JIC somebody else puts fuel in

 

[Kenneth Johnson]

Done. It was about a two hour job and now a lot less can go wrong.

Does it smoke?

 

[Blkrvrbart]

No it actually smokes less than it did. I was running premix with the injection system working for the new motor break in time. It smoked like a coal train then, just lightly smokes at no wake speed now.