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Old 05-24-2014, 04:37 PM
Theon Theon is offline
Motorized Bicycle Elite Member
Join Date: Jan 2014
Location: FNQ Australia
Posts: 1,440
Default Re: How do You break in your ht motor?

Re. Break in.
It would be irresponsible of me to tell people to break a motor in the way I do.
But anyway I've built a few different types of motors over the years, but I liken these engines to an old air cooled V.W. engine. Whilst I was studying engineering as a 19/20 year old I did a while as a V.W. mechanic for a place called Custom Off Road.
And these guys built some really fast off roaders, they use to take home trophies everywhere they went.
Now these motors got stripped down before a race, and received a new set of piston and rings.
When I asked how they ran these motors in with the race tomorrow?
They told me "As we put it on the trailer!"
I was told, To break a motor in, you got to get it hot, you got to use the whole rev range, and you want to do it with out putting the engine through undue labor.
Now a side note to this is the more revs you use on that motor the shorter its life is going to be. For every 1000 revs more that you wring out of that motor, halve it's life span!
Important thing though, have your mix either correct or a little rich.
Now when people run a motor in at 16-1 or something stupid like that, the more oil, the less fuel, the leaner your motor is running!
So, up here in the tropics is hard on two stroke motors, the humidity and the heat require a little more oil, So for breakin I put one tank of 25-1 through my motor. then switch to 40-1.
In a more suited climate make that 30-1 for break in and 50-1 after break in. And then if you feel inclined 100-1 of the right stuff.
Now all my motors are stripped, cleaned, checked, and set up with patience, experience and care.
This is one of the reasons why I feel that it would be irresponsible for me to recommend a "quick run in", as, if the chances are your motor wasn't?
Therefore there could be any manner of poor workmanship, and on stripping these motors you can pretty much guarantee to find something a miss, that needs a little more time to bed in.
Something that hasn't been lubed properly, and/or something that was dirty.
This may not go down well with 9000 RPM straight off the bat.
Now my attitude is pistons, rings, gaskets ect are cheap, the motors are easy to work on, and I don't mind having to replace these things every now and again to maintain performance.
In fact it gives me the opportunity to tweak it some time and inspect bearings ect, and lessen the chance of major catastrophe. This is not necessarily so if you do not know what your doing!
And this is it, if you don't know what your doing, be nice to the little motor whilst you run her in.
If you trust your motor, and you don't mind giving it a strip/rebuild every so often, give it heaps.

Last edited by Theon; 05-24-2014 at 05:51 PM.
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