break in,.. works well

[anthony_marquart]

I rebuilt a NR 5P today.. new P/L and Rod.. I went to the pond and took off the water line,.. ran 6 tanks super rich so that the motor would not really get on the pipe,.. it came in pretty warm,.. running lots of fuel through the motor. The last tank I put the water back on and leaned out a bit... at the end I was able to start the motor with the plug tight and I brought it up to maybe 40 mph. I think this process of break in really works well. The liner looks nice and is getting the polish that took tons of fuel when done with cooling water...

My point... The isea of break in with not water to get hot,.. and running real rich seems to work very well... still real tight at the top,.. but not bad now at all...

real pleased....

 

[Hayden Bright]

If your engine is cold all your doing is wearing out your piston, heat expands your liner & when it's cold your asking the piston to go through TDC that has not expanded, so the result is wearing on the piston

I think the best way to break in a engine is with water cooling off & just out of a four cycle tune so the engine is making some power, and run it at full throttle, this way it's getting heat from the load & with the full throttle it's flushing particles also.

It's the heat & expanding thing that's so important

This method is what OS recommends also, so it's gaining popularity.

 

[RobertWurster]

yup thats how i break my engines in.Hey Anthony Whats your needel settings for break in.and fule % my new 5 port is set at 7.5 turns in from factory but thats seems lean to me for 50 % Thanx Robert

 

[anthony_marquart]

I run a remote needle so I can't tell you what that would be on the factor needle. I run 65% . In a .21 you will see a huge power increase going from 50 to 65. To me the biggest advantage to breaking in like this is that it cuts the time in half compared to the rich runs with water cooling. I will probably run 4-5 more tanks like this and then just go for the power...

I put bearings in this motor too,.. The motor was not running badly and the p/l was still pretty darn good. Maybe 6-7 gallons through the motor. More than once I have rebuild a motor like this and never got it to run the same again.. I think this time will be successful. The seal from the crank to the case was really what I was worried about loosing. I think it's still good..

Some people look down on the lowly NR 5P,.. but honestly, I thinks a actually a very good, very versatile engine. My rigger has gone just under 70 in heat trim, it's all about matching the pipe, prop, fuel and getting the head clearance right

I ramble,.. sorry,.. no boaters around to chat with..

 

[RobertWurster]

Its all good i love talking boats or any thing really.soon as i get the $ im sending this one to Steave woods for his mods and carb mod.This winter im going to build the gp 335 to put it in

 

[anthony_marquart]

the 335 may be too big for a .21,.. That's a pretty big boat,.. I think Phil Thomas 40 boat is 36 inches., You might consider the 310,.. th

at is what I'm building..

 

[RobertWurster]

Ya maby my curent sport 20 is 16 w by 30 l.