How to break in your nice new 4 stroke engine

How to break in your nice new 4 stroke engine.




The way I break in a NEW or REBUILT 4 stroke engine is with HEAT   CYCLES


I want to let you know now that this is not hard to do. It IS tedious and will take most of a day. After this procedure, your engine WILL be broken in properly.


You don’t see an Indy car driver going around the track at ½ throttle to break in the engine!! No, it’s all done on the dyno before that engine ever went into his car. I do the same thing with race bikes on our dyno and you can do the same with your ride.

Heat Cycles are what are done on a dyno to any new race engine to break it in.

The good news is it’s easy and simple to do.

The main thing you want to do is heat up and cool down the engine in a controlled manor.

Say you just put a new engine in aYZ450 dirt bike and you want it to last a long time and run strong.

Now I must clarify that this break in is for a BRAND NEW ENGINE that you or a shop just put together.

If you just got a new bike from your dealership, remember that the engine was put together at the factory and run on a dyno, than the entire bike was assembled and run on a dyno, put in a box and shipped to your dealer. They did the final assembly and maybe jetted it and took it for a test ride. Now you get your brand new bike. It HAS gone through SOME of this break in, so the very beginning of this is already done.

On a NEW or freshly rebuilt engine, make sure it’s ready to go-oil in it at the correct level, coolant full and basics.ign. and cam timing are set.

#1- Fire it up and keep it running at a low rpm-enough so it doesn’t stall for 5 minutes—DO NOT put it in gear or ride it, just let it run.


#2- After 5 minutes of running shut it off for 10 minutes.


#3- Fire it up again for 5 minutes and just keep it running.


#4- Shut it off for 10 minutes.


#5- Fire it up for 10 minutes.


#6- Shut it off for 10 minutes.


#7- Fire it up for 10 minutes.


#8- Keep adding 5 minutes to the run time but keep the 10 minute cool off time. If you put your hand on the cylinder after 10 minutes you will find it cools off quite a bit in 10 minutes.

What we are doing during this heat up and cool off time is getting the piston and cylinder up to temp, which gets them to proper tolerances—cold—a piston is not round—it’s tapered and out of round—at operating temp it is round.


#9- After you get to the second 15 min warm up, go ahead and ride it EASY-1st and 2nd gear only—for the 15 minutes, than the 10 minute cool off.


#10- You can now ride it for the remaining 5 minute increments until you reach the 30 minute ride time still with the 10 minute cool off.


You have now run it for two 5 minute times and added two 5 minute run times to each until you reach 30 minutes of run time with 10 minutes of cool off time each.


I hope this makes sense—you want to heat it up and cool it down-WITH OUT a big load on it until now.


NOW the fun part.


You should now be up to a 30 minute run time.


#11- On the second 30 minute ride, at about the 15 minute mark you want to put a full load on the engine—Here’s what is happening inside, All the new parts inside your engine want a easy break in and get to know each other—except the piston rings—they need to work to break in—So now the parts inside are warmed up and happy—now the rings.


#12- During the second 30 minute ride you should have your riding gear on and at the 15 minute mark from a fairly low RPM hold it wide open in second gear until near the rev limiter—this will only take a few seconds—now stay in second gear and let off completely, after the engine gets to a lower RPM, shift up and ride out the rest of the 30 minutes to get rid of the heat you just generated.


You just seated the rings against the cylinder wall and at full throttle with very little oil, when you backed off at high RPM you created a lot of vacuum to pull oil up past the rings and help rinse away very small particles of metal removed during this process.


#13- Now the 10 minute cool off.


#14- 30 minutes is the maximum amount of run time.


#15- On every other 30 minute run, See #12-  do the wide open portion and don’t forget to cool it off by riding out the rest of the time.


#16- I’ll do this until I use about ½ tank of gas.


I know this is a pain and will take you about 1 day, but your engine will thank you for a LONG time.


Now change the oil and filter, check the coolant and go have fun.






This works great. You do NOT need to remove the engine to change out a bad starter. To begin remove the hood, side covers, belly pan plate, the oil filter and drain the oil from the engine and the tank. (the oil filter must be off to get the starter out) Remove the steering shaft that’s above the air box (I remove the tie rod at the front of the sled) I do this by putting the nut back on about half way and use a 12″ pipe that just fits over the threads but not the nut and hit with a hammer, it’s a tapered fit and pretty tight. now swing the shaft out of the way with all wires and cables from the handle bars attached. Now remove the air box. From here you can remove both front motor mount bolts. You do not need to loosen the long rear motor mount bolt.I than raise the front of the sled enough to to get under it and remove the starter motor bolts (a 12mm ratchet box wrench works great) and the 10 mm nut on the battery cable.Now pull the starter out of the engine and notice how close it is to coming out the bottom, set it in a spot as close to coming out as possible. I now get another person to help me and with two long pry bars going in from the sides prying against the frame and a safe place on the engine, move the engine back about 3/4 of an inch and the starter motor falls in the drain pan under the oil filter. I find that there is enough flex in the exhaust flex pipes to allow the engine to move back the small amount you need. You do not need to drain the coolant or remove any more parts to do this. with two people holding the engine back again you can get the new starter back in. Put all the removed parts back on and enjoy all the time you saved from flat rate. Yamaha now offers a replacement brush kit for this starter, now you don’t have to replace the whole starter   Ray


After working on a fleet of Yamaha’s this winter I learned some very good time saving short cuts. This one is on the Phazer 500 4-stroke.
If you have one that had a stator fail, most shops would remove the engine to change it.
What I found, You can change one in about 2 hours.
You will need to drain only the engine oil and remove the oil tank.swinging the battery box and wires forward, leave the radiator in it’s stock position. remove the plastic body parts to get at the voltage regulator (top left in front of the handle bars) unplug the large connector with 3 white wires (it goes to the stator) Now is a good time to test the regulator, if the stator is bad it may be too.
Unbolt the water pump, but do not split it or take off the hoses, swing it out of the way and unbolt the stator cover (the lower left allen bolts will need a swivel socket and most are in with loctite) The cover will be tough to get off because of the magnets in the flywheel, don’t get your fingers in between the cover. Now clean off the old gasket material, install the new  stator in the cover-Don’t forget to red loctite all bolts that go inside the engine- and reassemble.

NOTE  the triangle bracket that held the oil tank can get bent in from mild crashes and may need to be bent out a little to get the mag cover out. I hope this saves you some time.



After 40 years in the motorcycle industry I have THE answer to the question  ” What oil do I put in my motorcycle and should I use an oil additive”

I HIGHLY recommend the SILKOLENE COMP 4 oil in either the 15/40 or the 20/50 grades.

I also HIGHLY recommend the oil additive made by BG called EPC  (engine performance concentrate)

These two products together make the best lubricating package I have ever come up with.

This is what I tell my customers: with this oil and EPC in your engine you will feel a difference at the shift lever with in 3 to 5 miles. It does make that much of a difference-you can feel it.

Now if you can feel a difference at the shift lever, that is less friction in your engine and the rest of the moving parts will be happy and last a lot longer too.   Also it cannot effect your wet clutch.

I have taken apart several engines with over 50,000 miles on them that used Silkolene oil and EPC and and they still had the hone marks in the cylinders, These engines had almost no wear in them.

For your car use BG MOA  (motor oil additive) it has EPC in it and a lot of other additives that your car needs and a motorcycle does not.

I bought a new Toyota 4 runner in 1988 and it got Silkolene and EPC after break in for it’s life. I gave it to my son with 420,000 mile on it and it still uses no oil.

I truly believe in these products and I have many 1000’s of cans of EPC  in many motorcycles and NO ONE has ever asked for there money back because it didn’t work, most times a rider will come back to tell me it REALLY did make a difference that he could feel.

Hey you have to change your oil any way, why not try this and then you can tell me how great it worked for you.

To find a BG dealer near you go to will answer any oil questions you may have and explains all there products.

I hope this information helps you decide what oil to use next.

Ride safe


Why Does A Two Stroke Engine Smoke So Much?

One question I’ve been asked many times by two stroke customers-bikes, sleds, or Atv’s.

“Why does my engine smoke so much when I first start it”.

Well going back to the last time you used it, the gas and oil going into the engine from the carb and oil pump are atomized into very small particles so they can burn and the engine can make power.  When you shut off the engine and it cools down these little particles will turn back into a liquid and settle to the bottom of the engine.

When you start the engine the next time, this puddle of gas and oil has no place to go but up and back into the combustrin chamber where this extra fuel will make it run very rich until it’s all gone. What also doesn’t help this is a cold engine will need the choke turned on to help start, this extra rich mixture adds to the averall rich mixture and makes the engine smoke a lot until it’s warmed up and blown out.

When you first take off the higher RPM will help blow out the liquid around the crank shaft and that’s what causes that rough running on on the first ride of the day.  This is normal and all two stroke engines do it, think of it as part of warm up.

Happy Trails


If you have any questions for me, please ask.  You will get a quick, accurate, answer and I don’t charge a dime!

After Market Belt Replacement On Your Sled

A common complaint I have received from many customers over the past 30 years is:

“I replaced the drive belt on my sled with a new one and now it bogs off the line or really doesn’t run right”.

What I’ve found is they bought an after market belt or tried to save money and bought a (cheesy) cheap belt.  The exact width, length and most important rubber compound is VERY important to how the clutch will grab off the line and shift.

I HIGHLY recommend that you run a stock factory drive belt on your sled, there are just too many variables with an aftermarket and your performance will likely suffer.


How To Read Your Spark Plugs, They Are Telling You What’s Going On in There

In a AIR COOLED ENGINE, the spark plug center electrode porcelain color can tell you how well your engine is running or can tell you how to get it right.

Basically the plug color is telling you the combustion chamber temperature at the time you shut the engine down.

If the engine is running well  and you pull the plugs while riding on the trail and you see a light chocolate brown color all is well—This would be an average of the throttle position and shut down at that time.

Stay with me,

If you are trying to jet your carbs after doing any type of mods—pipes, porting, heads, carbs, clutching or gearing, You are going to have to do this.

First lets get it down on how to do a PLUG CHOP

This is what you have to do on a test ride each time you want to test the particular  change you did to the carbs.

ALWAYS do only ONE change at a time or you won’t know which one is working

First get yourself a new box of NGK spark plugs of the correct type for your machine, this testing will take quite a few NEW plugs.

Now warm up the engine in a area that you can hold the throttle in one position for at least 1 mile ( a lake is great for this) with a set of usable not new spark plugs in it.

Doing a plug chop plug chop on a snowmobile can be dangerous, So you must have your head on straight (no beer or drugs)

Right now I’m not getting into carb jetting or systems, I’m assuming you know what change effects each system of the carb—I will be doing another article on carb jetting later—Right now I’m trying to get you to know if the adjustments you are doing are working.

Say you moved the needle  one clip position and your trying to get rid of a flat spot.

We want to get the engine RPM up to the throttle position that your testing (a neddle clip change works around ½ throttle)

So here we go, you have the engine all warmed up and cleaned out (from several test runs to make sure it’s safe). Replace the plugs with a set of new ones (they will be hot-use a rag to handle).

A plug chop is getting the engine to the test RPM as fast as possible and MAINTAINING that RPM  for at least 1 mile with out changing the throttle position AND shutting down the engine as fast as SAFELY possible.

With the warm engine with new plugs in it, Have all your gear on, Start the engine and go to half throttle as fast as you can and hold it for at least 1 mile-try not to move the throttle—after the 1 mile you need to be on a flat smooth spot and hit the kill switch on the handle bar and lock up the track with the brakes and CAREFULLY slide to a stop. If you start getting side ways, let up on the brakes a little—DON”T roll it and hurt your self.

So we got the engine up to speed, held it for 1 mile and stopped the engine as fast as possible.

Now reach into your pocket and get the spark plug wrench you put there and remove the very hot plugs.

Congratulations,  you just did a plug chop!!

Looking down the inside of the plug porcelain you are looking for a ring of color or a band about 1/8”to 3/16” wide. This is why you use a new set of plugs each time you do a plug chop, this ring will only show up one time.

If you went far enough on that plug chop ride you can get enough color to cover the whole electrode and it will look like a regular new plug with color—just go by the color—a great running engine will have a light chocolate brown color—darker is richer and a lighter color is leaner, You can adjust the jetting and try again.

I do this at low speeds to wide open, each a new set of plugs and test ride and it can take most of a day, After this you KNOW it’s running right!!!

I hope this makes sense and works for you-Remember your controlling the heat inside the engine, and that heat is coloring the plugs.



Snowmobile Mid Season Check Up, Is Your Sled Running Like It Did Back In Nov.

Now that you have been riding your sled for part of the season

Is it running as good as when it first hit the snow?

There are things that you need to check that wear or get out of wack as you ride.

First lets take a look at the drive belt:

The clutching on a sled is the heart of it’s performance, it is what allows the engine to rev to it’s max horse power RPM. (shift rpm) more later.

An easy way to check the belt for burned or narrow spots is to ride your sled from a dead stop and very slowly accelerate to about 5 or 6 mph (this should only move you 20 to 30 feet). If you feel any jerking or pounding as you pick up speed you have a bad belt and it really should be replaced.

These narrow spots allow the sides of the clutch to move in and out each time the bad spot goes by and beat the heck out of it, after about 10 to 15 mph you won’t feel it any more, but the damage is still being done to your clutch.

The other thing to look for is normal wear (the belt will wear narrower) and sit lower in the secondary, If it gets too low the clutches will not shift correctly and it will be like taking off in your car in second gear. No power off the line!! If you want to maintain that like new performance this is also time for a new belt.

So how does the clutching mechanism work on a sled you ask, here is a simple explanation:
The primary clutch is the one on the engine and spins any time the engine is running and is the smaller diameter of the two. It controls the engine engagement rpm and most of the shift rpm. It’s the one that gets you moving from a dead stop.
The secondary clutch is the larger of the two and controls the back shifting and some of the shift rpm. Basically the two clutches work together to maintain the engine rpm verses the ground speed.
The way it SHOULD work is: From a dead stop, if you hit the throttle wide open (on a safe flat area) and watch the tac the rpm should go to your sleds shift rpm (found in your manual or call your dealer) and NOT change until you hit top speed. If the rpm drop or go over, you have clutch issues, I
will do an article on clutch tuning and set up soon. If you can’t wait and want to learn how to tune your clutch NOW I recommend OLAV AAEN’S CLUTCH TUNING HANDBOOK. It’s the best book on clutch tuning I’ve ever seen and I use it.

Next lets take a look at the spark plugs:

Pour or missing spark is one of the primary performance robbing problems. Start by removeing them and take a look at the center electrode, porcelain color-it should be a light chocolate brown Not black and shiny. If they don’t look great,

replace them—it’s an easy way to keep your sled starting easily and there cheap. On replacment spark plugs, I highly recommend the NGK brand. They have a wider heat range and just start better and last longer, just my opinion, after 40 years of experience.

A neat piece of information to know: If you are having a running problem and can’t seem to find it (everything you checked is ok) Remove the spark plug caps from the wires and connect an ohm meter to the screw sticking out from

inside the cap where the wire was and put the other test lead to where the spark plug goes, set the meter to the “K” ohms scale and tap the cap on something hard (your work bench) and see if the reading changes, make sure your making

good contact while your tapping it. Try it several times per cap, if the readings change you just found the problem. There’s a small resister inside the cap that looks like a small stick of carbon and it can bust up to a

powder and not allow the spark to pass through causing a misfire.

Way to go your a trouble shooting expert-Tell your friends.

Other things to look at:

The wear bars under the skis:

These wear down as you ride crossing a road or along a road with one ski on the road. They are designed to wear instead of your more expensive skis but do need to be replaced when worn.

Pick the tip of the ski up and look or feel the metal bar running down the center, if it’s flat or a short piece of carbide in the center of it is really dull you should replace them-the sled will steer much better on hard pack with new wear rods.


These are the long black or colored pieces of plastic that the track is running against. Looking at the side of the sled, you can see the slide rails that the suspension connects to (they are aluminum and are curved up at the front) On the bottom of these are the hyfax, they rub against the metal clips on the inside of the track and when you are in snow the pressure and weight of the sled turns the snow into a thin film of water witch lubricates the hyfax and metal clips-this works very well as long as you are in enough snow to keep them wet.

If you ride long distances on a hard packed roads or on glare ice, they will dry out and melt ( it takes 425 degrees to melt hyfax) There is a wear indicator along the side of the hyfax (if you look at the curved part on the front where the track doesn’t touch you can see how thick they used to be) if they are down to the wear line they need to be replaced.

I will be doing a article with pictures and video on how to do this your self the EASY way.


Check all lights each time you ride. The most important one is the brake light-You don’t want someone running into the back of your sled. You can easily tell when the headlight is burned out but you won’t see the tail or brake light unless you look.


Make sure the oil tank is full of the correct type of oil for your machine each time you ride.  Check the oil level of the chain case. It can use a bolt you remove, a dip stick or a level window you look in, Just make sure there is enough and do change this oil at least once a year. It doesn’t hold much and it does work hard.

Brake pads:

Look down each side of the brake disk and check how much pad material is left, most pads have a slot to indicate a wear limit.

I hope this gives you something to check and keep both you and your sled HAPPY


Say Hello To Ray and His Son Adam

Say hello to Ray and His Son, Ray is the more experienced one on the left.