Breaking in an SBT 657 in a 94 SPX - Sluggish?

[randomguy]

Hey everyone:

I'm doing breakin on my old beater. Starts very nicely, but it seems like it's really sluggish. I elected NOT to use block-off plates so I'm running break-in oil at 50:1 plus the injection pump. With that much oil, will the engine run "normally" or will there be a noticeable difference in operation?

I ran the first section (up to 20% throttle) and cooled for half-hour. Then ran the second section (up to 50% throttle) and was done for the day. Went back out the next day and it was terrible hard to start it and very sluggish. Charged the battery and put in a fresh set of plugs. It started great after that, but still runs pretty slow.

I ran through my first 5 gallons in around 2 hours. Does that seem a little quick for 5 gallons or am I dreaming?

So that's where I am now. I've run the third section (up to 90%) throttle for 30 mins and have been through about 6 gallons or so of pre-mixed gas. So I guess my plan is to run the last of my 10 gallon mix through, put some regular gas in and another set of fresh plugs and see what happens. Other suggestions?

Thanks!

 

[470]

What till your done with break in to pass and judgements. It will run different with premix. I break my motors in differently but everyone has their own way, which aren't wrong just get different results.

 

[Dr Honda]

Yep.. rings need to seat... but if you only burnt 5 gal in 2 hrs... you aren't pushing it very hard yet.

As above... give it a little time, and some straight gas to pass judgment.

 

[spx800]

Ride it hard, don't baby it. I'm NOT saying go wfo for a mile, but give it short bursts from idle to wide open and let off. This has worked well for me and others I know.

 

[randomguy]

Thanks guys, this is what I was hoping to hear. But it seems to be pretty bogged down. It just seems to have enough power to get going fast enough to "level out" and that's about it. Out of town tomorrow, will hopefully have a few hours to run the premix out of it on Sunday.

Thanks again for all your help!

Ride it hard, don't baby it. I'm NOT saying go wfo for a mile, but give it short bursts from idle to wide open and let off. This has worked well for me and others I know.