Triumphrat

RII

Oh sure, so now we're going to turn this into a "proper break-in proceedure" thread!

Think I'll pass on this one myself...

__________________
A GOOD friend will bail you out of jail, a TRUE friend is sitting on the bench next to you saying "Damn, that was fun!".

JohnA

Well maybe if we've exhausted the 'to hone or not to hone' question and if anyone wants to move onto other aspects of how to deal with treatment of new pistons/rings, that's ok?

Personally, I have to say I find the extremes of thought at each end of the 'how to run a rebuilt engine in' question quite perplexing. After a full rebuild I've always got the engine started and first got the carbs set up (mixture, tickover, synch), then strobed the timing, and in the meantime checked for proper oil return, any oil, petrol or exhaust gas leaks etc, and only after all this was completed even thought about setting out for a ride. By that time the engine would have run for some time, gently. It may well have been turned off and restarted more than once. All this seems perfectly normal, and it seems bordering on reckless not to proceed this way!

Surely it can't be good practice to have finsihed a total rebuild, get the engine started for the first time and then immediately roar off down the road without making the checks & adjustments mentioned above? Or are some mechanics so good they can get everything spot-on without needing the engine to be running?

Anyone who's followed the 'kick & let rip' approach and found it a good system has been lucky, in my humble opinion!

Mr.Pete

The normal procedure to bed in cam and tappets is to run at no less than 2000 rpm (some will say 2500rpm) for the first 20 minutes.You can stop the engine completely,then re-start;just don't have it running slowly.
You get more splash lubrication than you would at idle,and over-the-nose load on the cam lobe is reduced because valve-gear inertia opposes the valve spring at full lift.

Running your engine on the stand at 2000 rpm won't help the rings,and you'd also need cooling fans.
You would be better to run it down the road and keep above 2000 rpm.You just need to find a good section of clear road.

Mr.Pete

The only difficult point is the ignition timing.It wouldn't matter if it's 5 degrees retarded,but it will matter if it's advanced.With EI,you have no choice and need to use a timing light.
It takes ten seconds to check it with the engine running.It will probably be wrong,so you stop the engine to adjust it.If it's out 10 degrees,you move the stator plate 5 degrees.Next time you check it,it's right.
*As long as the throttle cables are synchronised,the carbs are OK.Set the idle stops 3/4 turn in,and the mixture screws 1-1/2 turns out.It won't be far wrong,but it will change anyway as the rings become seated.You won't be doing much idling if you want the rings to bed in.Do the final adjustment after 10 or 20 minutes.
*Any fuel leaks will show without even starting the engine.
*You can stop the engine after you've run it for a minute under load,and check for oil leaks.
*At the same time,restart the engine for a second and check return oil flow.If it's there a minute after start-up,it's OK.You didn't need it before that.

JohnA

I'm sure you're right Pete, you obviously know a hell of a lot about these bikes. But until I can see your method perfectly clearly in my own mind, I'll err on the side of caution. I've built quite a few British bike engines over the years and never had any problems using my 'oil everything liberally when assembling and ride gently to begin with' method!

I must admit that I've only stuck to the 'ride gently' part for fewer miles than most people seem to recommend (typically a couple of hundred before winding it on a bit, and maybe 500 before occasional near-full throttle bursts). That probably sounds really wimpy to you, but it's always seemed right on the edge to me - I go by 'feel', and if the engine's running nice and free, I give it a little more gas. As far as I know I've never had a bike whose performance has suffered in any way due to this treatment.

lovecuba

Understand, have the open road, 17k to a Country Pub, 17k back with engine working above 2500rpm, not lugging but easing up the revs then buttoning off there and back.

Ohio-Rider

This may be one of those topics where todays newer procedures are in conflict with when these thirty plus year old bikes where made. Mr. Pete has everything dead on correct in my opinion. I have no experience with electronic ignitions but I do see the concern, yet, if it starts and sounds good, break it in the way you’re going to ride it.

Old Cafe Racer

FWIW, the six times I've set my timing static on my TriSpark it's been spot on with the strobe.
(TriSpark has a built in led timing led)

motobob

I started using the Mr. Pete break-in method for over a year
Two Triumphs , a BSA 441, over a dozen airhead BMWs and a couple of old Honda 4s. No problems and they all quit smoking in less then 5 miles.
It did take me a while to work up the nerve to try the Bon Ami trick.

JohnA

OK, so the "Mr Pete method" (I doublt whether he'd want to take all the credit for it!) works fine for all you people, I'm happy to accept that as a fact if you're telling me. But this method still seems to me to be trying to solve a non-existant problem. I have never had any trouble running engines in the old-fashioned 'safe' way. My current TR7 didn't smoke at all from the moment I first started it - in fact I've never had problems with smoking engines except for the occasional wet-sumping and much rarer totally knackered top end.

If the 'oil well and take it easy to start with' method that everyone used to swear by doesn't cause problems, why risk thrashing a new engine?

Is it the case that some people have found problems with bore glazing or whatever, and this has been attributed to taking it too easy? I can believe that, but only for those engines driven absurdly gently for extended mileages. Sorry to be going on about this but the subject seems important to me. There must be plenty of novices reading this forum and I wouldn;t want anyone blindly following advice only to regret it when their pistons seize or scuff to hell!