125-200cc running in a rebuilt engine

Hi my wre 125 has just had new main bearings, seals a crank rebuild and new piston how would you recommend i run it in. I have read about so any ways of doing it some people say three heat cycles and its good to go yet some say take it easy for 25 hrs before opening it upany advice would be great thanks.

Like you said everybody does this a little different. What I do is start the bike let it run at low rpms on a stand blipping the throttle slightly every once in a while getting the bike up to operating temps. This usually take less than 10 minutes. I cut the bike off and wait for a cool down. As it's cooling I look it over for leaks and such. The next start after it gets up to operating temp I put it in gear and ride off for thirty minutes or so. I vary the rpms with no load and low rpms; no hills. Let the bike cool back down. The third start, same procedure with a little more rpms and a little more ride time, no loads and no substained rpms. Cool down again. The forth start I warm it up and may run it up to 3/4 throttle with up and down rpm runs; no real loads with the ride timel an hour or so. Then another cool down. After this I warm the bike and let it rip in short burst. By this point I have a couple of hrs on the bike, change the oil, re-check bolts/clamps, and ride it like I normally do. I have 9 acres with a huge field in the rear which is perfect for this. I make a day of it and keep track of the times as I go without rushing through it. It may be a little overkill but it seems to work for me. I'm 53 now and between my son, grandkids, and my bikes it works for me.

25 Hours before opening up

what actual happen when running a motor in is to polish and adapt all components to each other

it means it have to grind and form (molecular level) to each other to get the rough edges off

that is obvious more friction thus more heat generation

you don't want to load the engine to much as it could get in the danger zone

bearings are already pretty OK when they come from the factory and don't need that much time to really getting better performance.

When changing bearings in an electro motor the motor is started afterwards and normally on full work load (no running in period in this case)
when you measure the temp of the bearing you will find out that the new ones are doing way better then the old ones.

in a motor engine what does matter is the piston cylinder combination (axial movement) first you need to make sure that the clearance of the piston and cylinder is in the right specs (piston does expand more then the cylinder).
second you have to lubricate a bit more to take care of the increased friction.

heat cycles are done to give the parts time to contract and expand in several stages so they are getting more evenly used to each other.
also it controls the heat part better in the very early stages of the adapting process)

after an hour of riding (not loading the engine to much ) you should be fine of loading the engine.

still lubricate a bit more then normally for the first 2 a 3 tanks of petrol (and adjust your jetting a bit (to the rich side))

This is for a 2 stroke

A four stroke takes a bit longer as there are more friction points in the form of axial movement (so more heat generation for a longer time span).

there is also less lubrication in the piston cylinder process (one of the tricks you can do is increasing the cooling process of this specific part of the engine)
yet this is not practical in the most cases when it is a motorbike.

Robert-jan

Ok thanks for the info i will take your advice thanks.

Well i refitted the engine connected everything up filled it with fluids and it fired up 2nd kick and sounds great i,ve done 3 heat cycles and rode 9 miles so far taking it easy i was going to take it out for 18 miles next time and then after that ride normally do you think this method would be ok thanks.

check your jetting!

its better to be a bit on the rich side in the start

Does the WRE come with a Oil pump system to mix the oil in the fuel?

don't change anything on this just ad a bit of oil on the fuel in the tank for the first 2 a 3 tanks

probably raise the needle a bit (if you jetting is already spot on) this is also only for the first 2 a 3 tanks of fuel

have fun and drive sensible the first tank, jumping immediately in the loose sand and give it to the bike is not the thing to do

Robert-Jan

Hi the oil pump failing is what caused all the damage to my engine so now i,m running pre mix only from now on with motul 800 2 stroke oil.

Auch that's a bummer that started the whole ordeal

Personally I am always a bit suspicious about these pumps (seen them on a lot of moppets in my younger years and seen them also failing a few times)
pre mix is the in the tank is my preferred choice

In Holland you where able to buy premix from the pump (Don't know if that is still the case, seriously doubt it)

success with the bike
Robert-Jan

I just went to start it and it would start for a second and die then on one occasion it fired up and ran for 30 secs then died now it will not start at all i have no spark now i put two new plugs in and checked for a spark by putting the plug on the head nut and kicking the bike over but nothings happening i took the ht cap off and put the ht lead on my thumb and kicked it over and i got no shock from the lead do you thing it needs a new ht lead thanks

A friend of mine bought a new TE310 and asked me how I run my bike in. I said about 25 miles on the tarmac then give it hell. His bike was not fitted with lights and could not be ridden on the road, so his solution was to do place the front wheel of the bike again his garage wall and do a burn out for ten minutes.

Check your key switch and your wiring
also ground wiring (frame wiring) of the CDI

measure the spark coil

and you might change the cap of the spark plug (sometimes this could also be the cause)

Robert-Jan