Break in, how many are running hot & cold cycles at home

[LazyBastard]

The manual does NOT say to NEVER EXCEED specified RPM, it says to AVOID PROLONGED OPERATION above specified rpm. In fact, this IMPLIES that it MUST be run over specified RPM for short bursts.

 

[welterracer]

Engines should be broken in under a load!! Otherwise the cylinders will glaze over and rings will not seat!

 

[vice108]

I've got 2-cycles complete so far, I'm letting it get hot enough so that the electric fan kicks in, the heat exchangers at this point are quite warm, is this getting it "hot" enough??

I'd say yes,

Do both heat exchangers under the sides of the tunnel run close in temperature before the fan turns on?

Does the fan stay on after the machine is turned off like a car sometimes does?

Has anyone heard what Yamaha has said about the fan and its operation under NORMAL conditions? Is this thing supposed to come on? Yamaha Hot Topic Question?

Me, I'd rather NOT hear the fan come on. That means it is running nice and cool like it should be because heat robs horsepower. But it is also nice to know if needed, it will come on.

The Yamaha tech who puts the sleds together at my dealer mentioned that on all the apex/attacks he's put together that the fan comes on after approx 12 minutes. This is idling inside the dealer garage after they are started for the first time.

 

[snowbeast]

Dave 583 is correct warm it up and rip it to max rpm for short burst than back off keep doing this until you reach 20 or 30 miles at that time your rings have sealed as good as they are ever going to,the rest of the break in is just for your bearings,track streatch,crank bearings,oh ya dont wait to change oil and filter,do it right away after 50 miles than go 500-1000 to bad they now come w/synthetic oil,its harder to seat the rings with that in there,oh well good luck in which ever way anyone decides to break it in,just do it under a load.

 

[snappy]

i wonder how much and how long the engines are run at the factory?i know on the few v-8's i have rebuilt camshaft break in is critical.as soon as the new engine starts you run it at 2000-2500 rmp"s for 15-20 minutes.

 

[vice108]

i wonder how much and how long the engines are run at the factory?i know on the few v-8's i have rebuilt camshaft break in is critical.as soon as the new engine starts you run it at 2000-2500 rmp"s for 15-20 minutes.

I know that as part of setup the dealers run them for a 15 minute period. I don't know if this is just idle time or if the instructions from Yamaha give them a different RPM to run at.

 

[Red2003]

I'm with LB (two times in one day!). If you bear down on the throttle for even a short burst, you'll be over 6000 rpm. Gotta hold it full-on to properly seat the rings, and like its been said, after 100 miles of putting around, its too late. I'd let it warm up to temp (feel heat exchangers) and take it out on the trail. Run easy for a bit, pin it for a bit, easy for a bit, pin it for a bit..... After about 50 miles, I'd change the oil and drive it like you stole it.