Sbt breakin - WOT

[fubada]

Hi All, I'm breaking in a new 787 from SBT. They say during the first 10gallons of fuel NO WOT, but Okay to go up to 90% throttle. I was out this weekend breaking in the engine thinking that 787/96 GSX max RPM is at 8000, so I ran around 7000-7200 a number of times thinking I was at 90%. Did I mess up? Is WOT measured by RPM or by the throttle switch? At no point was I squeezing the throttle switch all the way down to the handle.

Thanks.

 

[Dr Honda]

UUUUmmmmmmm.


The red-line of the 800 engine is only 7200 rpm. Why would you think it's 8000 RPM?

As far as... "did I mess it up?"... do a compression check. Since it's a fresh engine... you should be seeing 150 PSI. The big problem is that when the rings are fresh, you won't get a good seat if you run at full throttle a lot. And the problem with that is... you won't develop full compression, and since the rings transport the bulk of the heat out of the piston crown... the engine will run hot.


I'm all for a hard break in... but you may have been running too hard.

 

[dsw222]

I'm all for a hard break in... but you may have been running too hard.

What do you recommend for break in, honda?

I read to vary the speed a lot, but can you elaborate?

My top end was reading 150 or a bit higher on both cylinders before running it... i only had it out for 30-45 mins max running it, but i dont want to mess it up after all that hard work!

 

[dsw222]

I found this write-up from SBT... do you agree with it?

I guess i may have blew it by running it already and not following the 20% rule. i basically took it out for a 30-45 min ride, varying the throttle every couple mins and dropping to idle a few times (and yeah i did do WOT for a few seconds here and there towards the end of the run)

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These instructions apply to all models with the exception of the RFI, DI and 4-stroke equipped models. For the DI models, do not add oil to your fuel tank. For the new 4-stroke skis, we recommend you consult your Owner's Manual and follow the recommended procedures.

NONE of the engine break-in can be done out of the water!

Proper break-in of your engine is the most critical aspect for determining the longevity and performance of your engine. Engines not properly broken-in will often fail within the first minutes of operation. Ring failure and piston seizure are the most common symptoms of an improper break-in procedure.

If you have a pre-mix system (mixing oil and fuel in the fuel tank), then you should richen the ratio to about 32:1 for the first ten gallons of gas. If you have an injection system (putting oil in a separate oil tank), then you should put 50:1 premix in the fuel tank along with the oil injection system for the first ten gallons of gas.

During the first 10 gallons of gasoline, there should be NO full throttle operation. First idle the engine for about 10 minutes to ensure that the engine is properly warmed-up. Then begin varying the throttle position up and down, up to 20% throttle for a half hour. Then come back and let the engine cool off completely - it should be a good 30 min break. After it cools down, you may now ride it up to 50% throttle for another half hour or so. Then come back again and let it completely cool down again. Now you can go out and ride up to 90% throttle. Continue this for the remainder of the 10 gallons, never holding one throttle position for more than a few seconds. Do not run at a steady throttle position and do not go to 100% throttle. After your first tank of gas, replace your plugs with fresh ones. For the second tank, you may ride normally with one exception - do not hold it at 100% throttle for more than a few seconds. After the second tank of gas, you are completely broken in and may ride anyway you like.