breaking in the 240 bbk

Budget_Blaster

New Member
Dec 25, 2009
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Illinois
Supposed to be 60's this week so im going to break in the 240 but got a couple of questions.

First should i use the br8 or br9 with the vitos kit and a +4 timing mod.the instructions say an 8 but it didnt mention anything about if you have a timing advance.im using their supplied jet needle as well as the pilot and main jets 340 on the main.

Second how do you guys prefer to break them in (im hoping ken oconnor can chime in)?

Ive always stuck close to the house and lightly rode it getting it plenty warm then letting it cool checking torque specs for a few heat cycles then taken thrm out and just rode it paying attention not to hot rod it for a little while (which is hard to do on a two stroke lol).ive never had any issues before doing it this way but i did just spend 500 on this kit and would rather not have any issues so id like to hear what you guys do and any suggestions.im using 93 and amsoil at 32.1.i plan to do the obvious like retorque and multiple plug chops but anyone got a "PROVEN" method?
 
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i broke my motor in this last time by starting it and putting around getting into the first 3 gears then shut it off for a few hours and repeated the same method increasing the intensity of the riding each time. the main thing is to keep varying the rpms dont just hold it in one spot and putt around. after doing that prolly 5 or 6 times i considered it broke in and have raced it alot and rode the balls off up untill i put it away a month ago.
 
Here is what I did:
1: Use semi-synthetic oil during break in...not real important but it helps the rings seat a little better in my opinion.
2: Started mine up playing with the choke but not leaving it on the whole time. Check for running order if it is rich and lean.
3: First time just play with the throttle a little bit....I never went over 1/4 throttle and mostly just let it teeter around idle....BUT not sit at idle. Just play with the throttle a little bit. I didn't even ride it around yet.
4: Second time, let it warm up and play around 1/4 and occasionally give some 1/2 throttle bursts....still without riding.
5: Third time, let it warm(I always do anyways to fend off scoring), ride it around but not over 1/2 throttle....vary gears and RPMs throughout the ride....not a real joyride....just go for a leisurely stroll.
6: Go out and ride to 3/4 throttle.
7: GO out and ride more aggressively and blip to full throttle burst every now and then, but not for long periods of time.
8: Just progressively ride harder up to longer full throttle bursts that are normals BUT keeping in mind to ALWAYS vary RPMS.

That's just my 2 cents......I'm really anal when it comes to breaking engines in.
 
I don't agree that you should "run it hard" right from the get go. Reason being is the rings aren't seated and you have a large amount of blowby on top of not having moving parts worn into each other properly. It's the equivalent of somebody breaking their engine in by just letting it idle and then the rings smack a gap and get screwed all to hell. This has been demonstrated numerous times by morons that buy brand new cars or rebuilt engines and think it's a jolly idea to go dyno them without breaking them in. My uncle helped out John Lingenfelter's staff for a while and helped some owners bring in mostly new and rebuilt vettes and they blew their sh*t multiple times......not because they wanted to.....but because the owner's insisted on doing it and $$$ talks. A fine example of a rebuilt engine going bye bye without a proper break in period....
 
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I don't agree that you should "run it hard" right from the get go. Reason being is the rings aren't seated and you have a large amount of blowby on top of not having moving parts worn into each other properly. It's the equivalent of somebody breaking their engine in by just letting it idle and then the rings smack a gap and get screwed all to hell. This has been demonstrated numerous times by morons that buy brand new cars or rebuilt engines and think it's a jolly idea to go dyno them without breaking them in. My uncle helped out John Lingenfelter's staff for a while and helped some owners bring in mostly new and rebuilt vettes and they blew their sh*t multiple times......not because they wanted to.....but because the owner's insisted on doing it and $$$ talks. A fine example of a rebuilt engine going bye bye without a proper break in period....
YouTube - "Blue Diamond" having a bad day

That was cool. I used to love blowing up cars when I was working at a repair shop . The Boss work buy old beater that customers didn't want to fix. If the motor had a rod knock, I would take it out back and hold it to the floor till it blow. Man I miss working there. We would do some crazy sh*t.
 
Break an engine in hard. dont baby it, but at the same time dont over do it. you dont need to rip a fresh engine WOT.
How do you know when your engine is fully broken in?
Simple, check the compression. as the rings seat the compression will go up. once the compression stays the same its fully run in. this takes about 20 minutes.
The first 20 minutes are the most important.
When we build and re-build race engine sometimes between motos or the day or morning before races we dont have hours to run tanks of fuel through them or do heat cycles etc etc. We break them in during the practice and heat races.
When you are breaking in a new top end the most important part is seating the rings. riding it easy does not produce the combustion pressures needed to force the rings out and seat them properly.

Use regular 2 stroke oil (not synthetic) start it, and while it is warming up check for any oil and fuel leaks. once the cylinder is warm ride it using big handfuls of throttle going through the gears but avoid going over 3/4 throttle. Dont run it at steady speed. After 10-15 miutes of you can step it up and start hammering on the throttle but avoid going WOT for more then a second or two. After about 20 minutes stop. let it cool, check the torque specs on the major fasteners and do a compression check.
For you next ride you are ready to run it like you normally would but again avoid WOT for more then a couple seconds at a time and steady speeds. keep your second ride short as well within 20 minutes. After check the compression. if its within 5 psi of the last time you done and ready to switch to a synthetic oil and ride it like you stole it.

MFGs and builders tell you to take it easy basically just to cover their own ass. the fact is if its going to blow up during break in it will blow up after break in just as easily. this is why we often break them in at the track or on a dyno or on tuning rollers. engine builder and mechanic like myself check the engines before during and after assembly, leak down tests are done before they are run and we know clearances are within specs... all that said there is NO REASON what so ever to break it in and putter around like a pansy.

it is a fact that if you break them in hard and quickly you will have higher compression and a stronger engine then someone that breaks them in slowly. I have been building engines for 20 years and only had one fail. That was due to the owner breaking it in at -20 degree temps with very little warm up time. the piston suffered a 4 point seizure. A fresh piston and rings (nothing else) and this time breaking it in during warmer weather with a proper warm up and the engine was perfectly fine.
 
I don't agree that you should "run it hard" right from the get go. Reason being is the rings aren't seated and you have a large amount of blowby on top of not having moving parts worn into each other properly. It's the equivalent of somebody breaking their engine in by just letting it idle and then the rings smack a gap and get screwed all to hell. This has been demonstrated numerous times by morons that buy brand new cars or rebuilt engines and think it's a jolly idea to go dyno them without breaking them in. My uncle helped out John Lingenfelter's staff for a while and helped some owners bring in mostly new and rebuilt vettes and they blew their sh*t multiple times......not because they wanted to.....but because the owner's insisted on doing it and $$$ talks. A fine example of a rebuilt engine going bye bye without a proper break in period....
YouTube - "Blue Diamond" having a bad day

you sure about that.....


"The Tune was right on the money.After tear down a streched Rod bolt was the cause due to many many dyno runs ,Drag racing and road course racing,including Daytona International Speedway.and of course excessive rpm"
 
I don't agree that you should "run it hard" right from the get go. Reason being is the rings aren't seated and you have a large amount of blowby on top of not having moving parts worn into each other properly. It's the equivalent of somebody breaking their engine in by just letting it idle and then the rings smack a gap and get screwed all to hell. This has been demonstrated numerous times by morons that buy brand new cars or rebuilt engines and think it's a jolly idea to go dyno them without breaking them in. My uncle helped out John Lingenfelter's staff for a while and helped some owners bring in mostly new and rebuilt vettes and they blew their sh*t multiple times......not because they wanted to.....but because the owner's insisted on doing it and $$$ talks. A fine example of a rebuilt engine going bye bye without a proper break in period....
YouTube - "Blue Diamond" having a bad day


Hold on, hold on. That was not a normal "rebuilt" engine. You could hear the supercharger sitting there whining as soon as they started it and if you watch the "in cab" view he had the shift light on for one full second before it blew. They had a guy sitting in the trunk because the straps didn't put enough traction to the dyno...

I'll call foul on using that video as an example of how not to "break in" an engine.

I used motoman's break-in process on my blaster. I let it idle for three 10 minutes idle periods (heat cycles) and rechecked all of the torqued bolts and nuts and then went balls to the wall with it. No trouble since. :-)
 
let idle to warm up, easy ride 1/4 to 1/2 throttle for 10 to 15 minutes max, then let completly cool, retorque everything. After cool down idle till warm and ride it like you stole it. This method is used by me and a close buddy who drags banshees with his dad. Yes he does rebuild every 2 months but because they are that serious. Same method on his trail blaster and goes through topends about every 3 years.
 
A lot of people attribute engine seizure to improper "break-in". But no one every looks at how well it was tuned at the time of the problem. No "break-in" will allow drivability if the tune is way off or the boost is too high like in the above video. I would sooner worry about dialing in my jetting and airleak problems before blaming a bad "break-in".
 
My two cents. I start the engine with the premix oil that I’ll be running. Don’t add extra oil to the gas. I don’t let it idle. I vary the engine RPM in short bursts checking the temp of the cylinder and head. I don’t let it get over 220 degrees. Shut it down and let it cool off completely. I do the same thing two more times. Check the cylinder and head bolts. I don’t run the engine at sustained high RPM for the first couple of hours and I stop often. Short burst at WOT are fine. Three mile trips up the road in sixth gear pinned are not. If the engine is going to the track, the break in is done long before race day. All bets are off if the jetting is lean.
 
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