Break-in questions

G

gunslingerburrito

New Member
Hello,

I just got my first mb up and running about 3 weeks ago. It's a Grubee Starfire 58cc Phantom kit on a Schwinn Clairmont Beach cruiser. So far, it has been fun breaking it in, just burned through my first tank. I had used an 18:1 ratio and upped it to 24:1 for the second tank.

I have, however, been hearing what sounds like a tapping noise in time with the engine strokes, especially at 1/4-1/2 throttle. What could be causing this?

Also, I have been hesitant to bring it up past 1/2-3/4 throttle for very long this early on. How soon should I be able to bring it up to mid throttle for a constant speed?

And, lastly, how soon can I safely begin riding longer distances? I've kept it under 20 minutes a ride, but I'd like to go further.
 
Break in procedures are as varied as the membership here. Read ( http://www.google.com/cse?cx=partne...orbicycling.com/f4/break-questions-35059.html ) and you'll see many different suggestions ranging from your current method to "start it and ride it hard".

I happen to be of the opinion that treating them too gently is not the way to go. I break in by enjoying my bikes. That means some hard running, right from the get-go.

As for limiting your initial runs; forgetaboutit. It serves no useful purpose to limit how long you run the engine during break in. Because they are air cooled engines and rely on air moving over the cooling fins, long periods of idling or running the engine in place is not recommended. I would suggest lowering your oil content to 24:1 then after a couple of gallons moving down to a 32:1 mix.
Good luck.
Tom
 
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18:1 is too much oil. I doubt it will hurt anything, but you really don't want to be using that much more oil on break-in. You want the rings to set in and for the rings and the cylinder to create grooves with each other, and using too much oil will lessen that.

If you really want to be safe, go with the ol' 24:1 mix on break in and then switch to a 32:1 mix.

Ride your bike as hard as you want during the break in. It's better for your rings, and I rode my bike full-on when I was first breaking it in.
 
Thanks a lot for the replies, guys. I noticed a power increase after switching the oil ratio and I've been keeping it up around 20-25 mph, very fun.

I had some grease oozing from the sprocket shaft hole, but from what I've read, it should just be extra grease from the factory.

Still hearing the metallic rattle, though. It seems to happen after about 10 minutes of riding, and it gets louder as the rpm's rise. I thought maybe it was the piston hitting the plug, but that seems pretty unlikely (plug looks fine, gap looks about the same)

Any ideas?
 
Believe me, if the piston was hitting the plug your engine wouldn't run. The piston would close up the electrode gap preventing an ignition spark.

These little Chinese wonders are notorious for producing some very strange noises; Screeching, rattles and howling, we call normal. Unless it impacts the way the engine runs, don't worry too much about odd noises. Check your chain tension. Too loose and it can make some disturbing sounds as the chain passes over the engine drive sprocket.
Keep us informed of your progress.

Tom
 
I have been riding and racing two-stokes for over 30 years and I have ALWAYS ridden new motors HARD right from the start. I believe they perform much better when you break them in like they are going to be ridden...Slow break in is for stationary engines and lawn mowers. The rings seat better and there is also the side benefit(?) of weeding out any potential problems right away...rathe than in the middle of a race. There is also no reason to limit rides to 20 min or less except to allow you to retorque bolts after motor is good and warm. Air cooled engines run about the same temp as long as air is flowing.dnut
 
Thank you very much for the answers, I switched to 24:1 and have been running for about 30 minutes, up to 28mph now. The weather has been around 60 degrees lately, so im guessing its cooling fine ;) This thing is a blast.

I bought the kit from bicycle-engines.com. I was very happy with the service, and the quick clutch and carb are great.
 
Grip it and rip it. Just ride it all over the place as long as you want. When it is broken in properly you'll hear a backfire (or POP) from the exhaust, that is the piston rings telling you that they are ready. You will come to find out over time that all kinds of factors will contribute to how the motor acts. Believe it or not but the weather can and will play factors with tuning issues. Some motors have a shorter temper than others. As far as the rattle and other little noises, like Tom said that is normal. SBP sells an engine sound dampener kit that will deaden the sound pretty good.


Sound Dampener
 
I've got to pitch in to agree with the others.
Too much oil is NOT a good thing for a new 2 smoke!

...and I've never bought a new 2 smoke motor that I did not have to put to work, right away... chainsaws, pumps, dirtbikes, streetbikes...
Just didn't have the time to coddle them.

I do make a point to vary my rpm, up and down, and not run absolutely top, highest rpm possible for at least a little while 'til the rings have seated well.

If I've run the brand spankin' new engine under load, I ease back a tad and let it cool a bit before working it hard again...

..just can't go out on a jobsite and tell the boss "I'm going slow, taking care of my equipment today!" lol

Yah, the chinagirls are noisy... some fellows go to the trouble of silicon disks or strips in the cooling fins, to ease the rattle a bit. Others put noise dampener products inside the clutch cover, and others put something over the cover.
Your rattle is probably not ABnormal, but if it does develop into a problem, well, we enjoy talking to you here on the forum! lol
Best
rc
 
F_Rod81 said:
Grip it and rip it. Just ride it all over the place as long as you want. When it is broken in properly you'll hear a backfire (or POP) from the exhaust, that is the piston rings telling you that they are ready.
Click to expand...
WOW...
I can't even find the words to respond to that piece of advice at the moment other than DO NOT FOLLOW HIS ADVICE!

My guess is the 'POP and Backfire' he thinks is good is a ring breaking because he didn't break it in properly.
Hey Frod81, how is that motor you broke in running now?

Or go ahead and go out and run it wide open for a couple of hours.
Let us know how well that works out for you in a month because no Backfire or Pop is a good sign your motor is ready for what, an even leaner oil to gas ratio and more power?

I'm not saying don't WOT, you need to, just don't run it continuously at that for for the first tank or two at 25:1 and do just as much lower RPM riding if you want to get the motor stronger no weaker.
 
Pull your plug..Look at top of piston for signs of interference..: i'e : I have seen 48cc HD.gaskets on 55's and 60's from the factory.But for real,sounds like you may have a weak or defective rod bearing..Upper rod fairer sounds more like your bike is running fat...wont get up to rpm very easy and just lacks power...Lower rod will usually depend on rpm,as in,idles ok,but mid range-to, lower top end may knock,or have vibration which may,or may not disappear, depending on rpm,crank-rod harmonics..in any case, something is not right and you need to diagnose you anomaly before you have damage or failier...new top end gaskets are cheaper than top ends.............. D
 
Wow! Whatever you do, do not take the "advice" of F_Rod seriously!
Pop?!? Yeah, she's broken, just not broken in...
 
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