Ross 63 Posted March 21, 2011 Share Posted March 21, 2011 Hi all, My YBR 125 gets delivered tomorrow and I'm keen to break the engine in so that it gives the best power and economy that it can. I know there are 2 different trains of thought on this: 1, The manual says that it should be ridden gently and full throttle/high revs avoided for the first 600 miles. 2, Lots of tuners and mechanics think that they should be warmed up correctly and then given a good caning for about 20 miles on full throttle to generate the maximum combustion pressure so that the piston rings create a proper seal against the cylinder bores. Then change the oil straight away to drop the swarf from the rings and bores and run as normal. http://www.mototuneusa.com/break_in_secrets.htm What would you recommend? Thanks, Ross Link to comment Share on other sites More sharing options...
Moderator Airhead Posted March 21, 2011 Moderator Share Posted March 21, 2011 I would go by the book, anyway 20 miles is a long long way on full throttle, more like occasional bursts of a few miles if you must Link to comment Share on other sites More sharing options...
Ross 63 Posted March 21, 2011 Author Share Posted March 21, 2011 I would go by the book, anyway 20 miles is a long long way on full throttle, more like occasional bursts of a few miles if you must Thanks for your opinion. I'm leaning that way myself now. I think it does it a lot of good to give it a good blast of full throttle now and again though. I'm going to change the oil after 100 miles, I don't think that will do it any harm. Link to comment Share on other sites More sharing options...
KirriePete Posted March 22, 2011 Share Posted March 22, 2011 Thanks for your opinion. I'm leaning that way myself now. I think it does it a lot of good to give it a good blast of full throttle now and again though. I'm going to change the oil after 100 miles, I don't think that will do it any harm. Every engine is slightly different due to manufacturing tolerances, only you will be able to feel if your engine is loose enough to take full chat early on. So take it easy and get a feel for how the engine is pulling, if it feels tight don't be tempted to open it up, let it bed in a bit more. The early oil change may be a good idea, gets rid of any big lumps of swarf, but don't use a posh fully synth oil at this stage - they can be too slippery to let the components bed in to each other - just use a plain mineral oil while you're running in. Mineral diesel oil is good as it doesn't have friction modifiers (clutch slippage issues) and it's got a lot of detergents to clean the crap out, so your internals should be sparkly clean. Once run in, get it back onto a good semi-synth bike specific oil and change it regularly. Here endeth the sermon .... Link to comment Share on other sites More sharing options...
Gas up - Let's Go! Posted March 22, 2011 Share Posted March 22, 2011 Running in is about many things... Firstly, how experienced are you ? is this your first bike ? The book says XYZ, and for some good reasons, Motobloke says something different and he has a long list of people who say they have followed his advice. Lets consider the worst case possible; Your engine oil pickup is blocked with some bubble wrap from manufacture, it's restricting the oil flow but looks fine at PDI, and off you go, canning it for 20 miles (although I'm with OG here, 20 miles is a long way to can a bike), the bike overheats, the oil isn't getting around fast enough, the piston stops dead in the barrel. Once you get out of hospital, you take whats left of the bike to the dealer and say "bloody thing siezed up on me, I fell off and I want it sorted" Dealer inspects the bike and says, the oil pressure is a bit down, but it's OK for running in, how the hell did you manage to heat it up enough to sieze it?" "erm, I was following Motobloke's advice" "Bye bye, and take you bike with you. If you can't follow the instructions then tough" ..... and you leave the dealer (still limping) with a trashed bike and no-one to repair it....... OK, so this is the very worst case possible and pretty much beyond imagination, but the point is there. The running in period is as much about ensuring the components are all working togther as pison compression. It's about working the bits gradually so any faults can be resolved before they cause a problem - this is why the first inspection service is free at the supplying dealer. You have a warrenty, a warrenty you have paid for, so why blow it for the sake of a few steady miles ? and those same steady miles will let you get used to the bike, bed in the brake pads and scrub the wax from your tyres. But it's your choice. Link to comment Share on other sites More sharing options...
Ross 63 Posted March 22, 2011 Author Share Posted March 22, 2011 Thanks for the helpful comments and insights fellas. It's not my first bike and I've built a few engines over the last 15 years but bore liner crosshatching and piston ring bedding are totally different on a small bike engine. The bike is a cracking little 125, great to ride so I'm really happy with it. I'll take it easy and stick with the book apart from the occasional blip on full throttle which I think is essential for a proper break-in. Ross Link to comment Share on other sites More sharing options...
2 Wheels Posted March 22, 2011 Share Posted March 22, 2011 I would go by the manual, nice and easy for a while, otherwise you will Glaze-over the rings instead of them bedding in propperly. After that i would bring on the revs higher then higher then full,,,,,,,,,,,,,,,,,,,,but only do it when the engine is at normal operating temp. Thats my thaughts on it sir. Enjoy your new bike an good luck with her ! Link to comment Share on other sites More sharing options...
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