4 Stroke Engine Break In Procedure

[Andi]

With the pending arrival of the Bandit XC-150z Scooter, I have been gathering information about anything pertaining to scooters. Hopefully to integrate my newly licensed wife into being a save, confident and consciences rider.

Engine Break In, is of course an important part to guaranteeing performance and durability out of the scooter.

I came across a radical "Break In Procedure" in the following link:

www.mototuneusa.com/break_in_secrets.htm

Not one to immediately accept opinions, but neither to dismiss new ideas, I kept looking and came up with an interesting comment about this radical procedure, in the following link:

www.motortrend.com/features/editorial/112_0603_technologue_race_performance/

I thought the following quote, I copied out of the text, was particularly interesting:

“For answers, I rang up long-time GM engine guru Dave Lancaster, and he agrees that in smaller, low-cost air-cooled engines (which expand and contract more as temperatures changes) such a technique might indeed pay off. But the micro finished bores, high-tension rings, and precision-build tolerances in today's automotive engines yield excellent ring sealing from new, so any change in power output attributable to such a radical procedure would be miniscule if measurable at all.” ……. “Ford's engine durability specialist Mike Herr concurs with all the above as do the engine R&D experts at Honda.”

Basically allowing for some validity to use this radical procedure, but only in small air-cooled 4 Strokes, such as scooter engines?

Anybody else have any thoughts and/or experiences they would like to share?

Andi

[earlwb]

I stayed conservative and went for a more conventional method, slow and easy riding without reving up the engine too high for long periods and chaining engine speed a lot, for the first 500 miles. Although at 300 miles I started pushing it a little more. It was really chilly and cool outside then so the engine had much cooler air than most to run in.
I'll leave the aggressive fast break in method for the drag strip, where they tend to rebuild the engines a lot anyway.

[bond007]

Broke in my Qlink Pegasus that way. Does not use oil. I believe it will work on china scoots but not necessarily all motorcycles. Some japanese are extremely high tech machines and it may not make that much differance. I disagree with a lot of motomans advice on other statements he has on his web site. Especially the use of JB weld in porting. That stuf is always temporary in its uses. I think some people just get off on looking important on web sites! David

[earlwb]

JB Weld is great stuff, but using it on the intake ports is questionable to me.
Aluminum isn't something that is very glueable at all. Aluminum forms a thin oxide barrier layer almost immediately upon exposure to air.
I would be really concerned with the JB weld coming loose and jamming up an intake valve or worse getting into the comustion chamber.
But then apparently it works OK as a lot fo racing guys use the stuff. But then they are likely to rebuild their engines a lot in the process, so they would notice problems faster than the rest of us.

[bond007]

One very good point Motoman makes that is probably undisputable. First Oil change at 20-30 miles is definately an advantage. I found some metal shavings and a little piece of rubber in my filter after about 25 miles. Not to mention smaller shavings from the machining process you can not easily recognize. Changed oil again today at 1400km and no metal or rubber shavings were found caught in the filter. I'm sure glad that stuff was cleared out early to avoid possible damage. Shavings from the machining process is normal. But discarding them early gives me much more piece of mind. I difinately agree with Earlwb on the JB Weld thing! Believe me time and experiance is a good teacher! Besides we are not racing our bikes for a short time, them rebuilding. I plan to ride it as long as possible or untill I trade up! Win win for me and second bike owner. JB Weld inside your engine? Go ahead be motoman's guest. He doesn't care blown engines are a way of life to him. Not my choice though!! Happy Trails!! David

[earlwb]

I agree on the oil changes too. I test ran my scoot at home for a while to ensure it was working. Then I changed out the oil, and found a small metal shaving and a couple of tiny tan colored bits of something in the oil screen. Then at about 300 miles I changed the oil again. Nothing caught in the screen that time. Then at 1000 miles another oil change. At 2000 miles I'll start using synthetic oil as the engine should be well broke in by then.

[larry9]

I suppose I should add my 2 cents worth. I've had several motorcycles since the early '80's and have always used a proceedure similar to Motoman's with good results. The first engine was my 600cc '67 BMW which after rebuilding it, broke it in at the advise of a road racer that I knew at the time. The proceedure scared the heck out of me as I never did it like that before. But after 36k miles on that rebuild the oil never changes color so the rings must be sealing pretty good.
Quite a few engines after that now I'm riding my scooters more than the motorcycle, but I broke in the Chinese scoot and the oil never changes color but I change it every year. My X9 was also broken in like Motoman suggested and I see no problem with the engine, but it only has 2200 miles on it.
However my wife's car was bought used and after 1000miles the oil is noticeably dark in color.
Well thats my 2 cents worth.

[pdaddy]

I will do this procedure on my newly installed 59mm bore kit.. just w8 on jets and other stuff before i can start her up

M

[reddragon35]

I have a jmst kingstar 150cc scooter 4-stroke and having a big issue with starting it. The engine had cut off on me about 2 weeks ago and had to walk it all the way home. I tried changing the spark plug but it started for 3 seconds and then shut off again; now it just wont crank over at all again. I need someone to give me some tips on what I may be able to do to get the problem resolved. Almost forgot I tried manually kickstarting it and all I got was a puff of white smoke coming out of the pipe.

[earlwb]

We have a lot of people with similar non-starting problems ask that same question. Peruse through the various threads we have here, and see if something pops out at you. it is basically a process of elimination, checking each possible problem one at a time, until you find the culprit.
Many of the provlems seem to center around the fuel system. A clogged tank vent. a vaccuum operated petock that isn't opening up. If you haven't done it, replacing all the fuel lines and vaccuum lines is a good idea. The cheap rubber goes bad easily. Also the cheap rubber intake manifolds are known to crack and go bad too. Sometimes if the manifold is good, it is leaking air at the base where it mounts to the engine. Using a good gas resistant sealer works well there.

[tofer]

what type of oil should i use on my 50cc 4 stroke
rocketa

[simony]

Tofer,
It should say in the back of your owner's/operators manual, typically 10-30 grade, I recommend that you run it in on straight mineral oil and do the 1st few oil changes ( up to about 1000 miles on straight mineral oil before swiching over to synthetic oil this will allow your rings to bed in and minimise oil consumption once you switch over.


Take care out there.

R,

Simon. ;D

[tomtom]

Andi - Read this research report by a professor at a California university. It's rather long but complete. He covers all the aspects of the history of oil, including whether to use synthetic during break-in. Read all about Mobil suing Castrol for claiming that Syntech was a full synthetic oil. Very interesting case.

www.calsci.com/motorcycleinfo/Oils1.html

[Dennis D]

Tom, since Castrol won that case several years ago... Mobile now won't give a straight answer to questions about the base for their "fully synthetic" oil. Answering only that what they use is based on performance rather than notions about which base oils are superior. Their lack of a clear answer leads most who follow that issue to believe that they too, are now using Base3 mineral oil as at least a large portion of the base for their "fully synthetic" motor oils.