Breaking-in a new engine

deacon · #41 (**permalink**) 11-04-2009, 09:45 AM

My two cents, worth less than a penny is, If in doubt be patient and break it in. I don't have the experience of either of you, but I do know this. I would rather run it thick for a couple of tanks and take it easy for a while, than to put another kit together. It took me longer to adjust the rear sprocket than to break the engine in.

Prasinos · #42 (**permalink**) 11-04-2009, 10:23 AM

if you sharpen the teeth of the sprocket on a grinder on the faces (think blades not points), it makes it WAAAAAAY easier to adjust. I sharpened mine and my chain tensioner can move back and forth a full inch and the chain wont come off.

**Bikeguy Joe** · #43 (**permalink**) 11-04-2009, 10:34 AM

I think you posted that in the wrong place...

Salty Gator · #44 (**permalink**) 11-04-2009, 10:52 AM

Quote:

Originally Posted by Bikeguy Joe

Salty- I won't dis-qualify your "qualifications" with my "qualifications", but I have been tuning and running two strokes and four strokes for about 40 years now.. I had a couple of small engines (one 2T one 4T) that I got just to run and tinker with when I was 10-11. Had mini bikes and engines of all kinds ever since. I have re-built and repaired motorcycle/car/aircraft/mowers/weed eaters/outboards engines, transmissions, ect.ect. ect.ect. ad nauseum.

I just tuned/worked on a 1976 Mitsubishi weed eater with a remote float bowl type carb no mower shop would touch. I have worked on everything from .010 cubic inch model engines to 1000 cubic inch diesels and all in between. I have lost count (not that I was actually counting)

I think this makes my point, no?

I KNOW these engines are different (very similar to most DKW derived piston ported two strokes of the 30's- the 60's.)

Maybe the "modern" two strokes don't need break in because people throw them away the first spring when the old gas won't light them off, and they never see enough service to know if they would last or not.

I was just wondering out loud.

Hey Joe,
You and I should start up a business then !.... LOL

....between the two of us I bet we could fix anything !....

Grins,
Salty

Prasinos · #45 (**permalink**) 11-04-2009, 01:26 PM

Quote:

Originally Posted by Bikeguy Joe

I think you posted that in the wrong place...

so i did....

Randog707 · #46 (**permalink**) 11-11-2009, 08:20 PM

I broke in my engine with 2cy synth and it runs fine.heres some oil to gas mixing ratios,
16:1 = 8oz oil to 1 gallon of gas
25:1 = 5oz oil to 1 gallon of gas
32:1 = 4oz oil to 1 gallon of gas
40:1 = 3.2oz oil to 1 gallon of gas
50:1 = 2.5oz oil to 1 gallon of gas

Randog707 · #47 (**permalink**) 11-11-2009, 08:24 PM

Heres a great link for finding out you oil to gas ratio..Gas Oil Mixture Ratio Calculator

rkorson4209 · #48 (**permalink**) 11-14-2009, 12:37 AM

Quote:

Originally Posted by GearNut

Putting a teaspoon of oil down the sparkplug hole could not hurt.

I recommend getting the better quality engine hardware kit from SBP and install it before you install the engine in the frame. Way too many folks have bolt failure soon after getting the bike together.

Really This is a good idea. I am getting another kit, just waiting for it. Should , or can i do it to the motor I already have, it only has 160 mi. on it. Never even heard of this, but now makes sense

GearNut · #49 (**permalink**) 11-14-2009, 12:04 PM

The hardware upgrade can be done to any motor, however if done to a used motor it is nearly a requirement to replace the cylinder base and head gaskets. On a brand spankin' new motor (never run) you can usually get away with reusing the gaskets, but that still is taking a slim risk of leakage.
Please note that is has been found that the threaded holes on a typical chinese HT engine are drilled much deeper than they are threaded. Nobody knows exactly why the threads only go partially into the holes. If you are doing a hardware upgrade you can further improve the upgrade by tapping the holes in the engine to increase the thread engagement on the studs. The more threads that the studs can engage, the stronger the install. The soft alloy that these engines are made out of needs all the improvement it can get! You need a metric 6-1.0 tap for the mounting studs, intake studs, and exhaust studs. The cylinder studs used vary from manufacturer to manufacturer. You need to determine the tap size specific to your engine.
http://sickbikeparts.com/catalog/pro...products_id=43

xlite · #50 (**permalink**) 11-15-2009, 06:31 AM

Personally I do not think replacing hardware for no reason is a good idea. Several guys I built motors for made matters worse doing that. IMO the original chinese studs, nuts, and bolts are fine if installed properly.