How Do You Run In An Engine Properly?

[Aleks]

I have recently put a Naraku 70cc kit on my (2 stroke) moped to get a bit more umph out of it but running it in is taking a while. So far I have done 100 miles and not gone above 1/4 throttle or 30mph, and I have been premixing the petrol with quite a bit of oil because the oil pump packed in, (not a major problem), however, Naraku recommend that I run it in for 1300 miles but has given no instructions... So I was wondering if I am supposed to do it in stages, or use some special oil or something because I want to do a proper job running it in (unlike most people).

Cheers.

 

[dandoolittle]

Just ride it like you would any other bike- Don't keep on the same revs for ages and engine brake as much as you can!

Don't red line it but don't pussy foot around...Just ride it and it will looked after you

 

[SalvageSV]

Yeah, accelerate briskly but don't rev too high. Avoid cruising at the same rpm for too long. On cars I'll change oil at like 50 miles then again at 500 to be safe.

 

[BurntRuber]

Is it just a cylinder kit? Is it a forged piston? If your jetting is right I would just go full out right off the bat. I used to build allot of scooter engines and I would put them together and go all out right away and never have problems. I mostly ran fully forged internals tho. But all the race bikes we build at the shop get built and go stright to the dyno and go for power runs. They never have problems and always hold up in the races. The moped engine doesn't really make enough power to worry about it.

 

[Revvin417]

Honestly, I have not personally seen, or have heard of, anyone who has had problems when not breaking their engines in "correctly."

But, be patient and do what others are suggesting.

 

[BurntRuber]

http://www.mototuneusa.com/break_in_secrets.htm

 

[lupin]

I've never seen any evidence of anyone saying the break in procedure did anything at all, and that's with well over 20 years in the motor trade.

It's not 1960 anymore things don't really need a break in at all. If it doesn't break on first start all it really needs is for the rings to bed in and to get any crap out of the engine.

 

[dandoolittle]

It's not 1960 anymore things don't really need a break in at all.

Absolutely! After speaking to a few 'insiders' - Its more than likely down to them covering their backs if bolts fall off more than anything else, forcing people not to rag the shite out of the machine etc, more than anything is gonna go bang

 

[Aleks]

Just ride it like you would any other bike- Don't keep on the same revs for ages and engine brake as much as you can!

Don't red line it but don't pussy foot around...Just ride it and it will looked after you

Thanks for the reply! I just wanted to be a bit careful because it is one of the cheaper big bore kits around and I can't imagine it being the most reliable. One question though: why is it a bad idea to keep it at the same revs for ages?

 

[Aleks]

Yeah, accelerate briskly but don't rev too high. Avoid cruising at the same rpm for too long. On cars I'll change oil at like 50 miles then again at 500 to be safe.

Thanks for the reply. Thankfully my moped is 2 stroke so I don't have to worry about changing the oil. How come I shouldn't cruise at the same rpm?

 

[Aleks]

Is it just a cylinder kit? Is it a forged piston? If your jetting is right I would just go full out right off the bat. I used to build allot of scooter engines and I would put them together and go all out right away and never have problems. I mostly ran fully forged internals tho. But all the race bikes we build at the shop get built and go stright to the dyno and go for power runs. They never have problems and always hold up in the races. The moped engine doesn't really make enough power to worry about it.

It is just the cylinder kit and I'm not sure if it has a forged piston or not. On the Naraku website for the same kit it says "A molybdenum coating ensures that the cylinder kit run in period is as trouble free event", and that it is built for torque. It also says that I would need to increase the jet size slightly which I have done, along with a new exhaust. Cheers!

 

[Aleks]

Honestly, I have not personally seen, or have heard of, anyone who has had problems when not breaking their engines in "correctly."

But, be patient and do what others are suggesting.

I've talked to a few of people about this and some have said they have had to replace their engine every couple of months while others have said they never bothered to break in their engine and have never had a problem. Some people suggest don't go above 1/4 throttle while others say accelerate quite hard but don't rev too high, so its getting quite confusing. Thanks for the reply!

 

[Aleks]

http://www.mototuneusa.com/break_in_secrets.htm

I've just read it but unfortunately it says it only applies to 4 strokes. Thanks for the reply anyways!

 

[Aleks]

I've never seen any evidence of anyone saying the break in procedure did anything at all, and that's with well over 20 years in the motor trade.

It's not 1960 anymore things don't really need a break in at all. If it doesn't break on first start all it really needs is for the rings to bed in and to get any crap out of the engine.

Thanks for the reply!

 

[SalvageSV]

How come I shouldn't cruise at the same rpm?

From my limited knowledge, it's about cylinder pressure and properly seating the rings. The more variance that you can give it, the more scenarios the rings experience while seating. They just get a more uniform seat instead of seating for the common cruise scenario. Most of this is random tricks from old timers anyway and not totally science backed.

I know that higher throttle percentages increases pressure on the rings and that changes how they wear, but the crosshatching on a newly honed cylinder is gone in under 100 miles in most cases anyway, so anything behind that doesn't do much for mating the rings to the cylinder surface.

 

[Aleks]

From my limited knowledge, it's about cylinder pressure and properly seating the rings. The more variance that you can give it, the more scenarios the rings experience while seating. They just get a more uniform seat instead of seating for the common cruise scenario. Most of this is random tricks from old timers anyway and not totally science backed.

I know that higher throttle percentages increases pressure on the rings and that changes how they wear, but the crosshatching on a newly honed cylinder is gone in under 100 miles in most cases anyway, so anything behind that doesn't do much for mating the rings to the cylinder surface.

Makes sense

 

[SighBored]

http://www.mototuneusa.com/break_in_secrets.htm

+1

 

[RoadSprock]

I wouldn't red line it myself, not really sure mind what there is to break-in as others said its just to cover companies from manufacturing mess ups.

 

[BurntRuber]

I build new motors all day for bikes and never once have I did a easy break in on one. I start them up and take it for a rip. The article I posted was 4 strokes because it talks about changing oil. That's not something you really have to worrie about.