New pistons and rings in! But now a snag on valve clearances...

[Fixxxer]

Hey, it's me again. Thanks again for all the help and advice that helped me figure out what to do with my bike. If you recall, I had two holed pistons and the consensus was that it was probably caused by a timing issue that was exacerbated by the lean condition produced by the lack of air filter, for which I place the blame squarely on the PO, even though I should have checked when I first got the bike.

Anyway, after spending more time than I ever wanted to scraping off the old gaskets, I have the new pistons and rings installed. After some frustration with the camshafts (the chain skipped a link and I had to start over) I have them timed correctly and the chain tensioner installed and working properly. Now it's time to check the valve clearances.

Well, they were all in spec except for the number 1 & 3 exhaust valves, which were .10 mm and .09 mm, respectively. From what I've been reading in old posts, the real danger with the valve clearances is when they get too tight, and if they are too loose they'll make some noise but there's not a great risk of damage... is this correct? My question is this: Is it ok to leave the valves as they are, put the valve cover back on, breather cover, carbs, etc. and get it running for now, order the appropriate shims, and remedy the clearances once they get here? Oh yeah, the exhaust valves in question are on the cylinders that had the holed pistons... I don't think the two things are related, but could they be?

One last thing: when I got the cylinders honed at the Suzuki dealership, I asked about the break-in for the new pistons/rings. He said not to let the rpms get very high, and not to stay at a constant rpm range for very long, for at least 100 miles. Does that sound right? How do you guys break your engines in after changing the rings?

Thanks for the help,

Tim

[Nessism]

It won't hurt the engine to run with the clearances you noted. If it were me I'd have taken the head apart and checked out all the valves and replaced the valve stem seals. Hopefully everything is okay.

Regarding the break-in, it's best not to lug the engine and use full throttle right away. You don't want to baby it though since you need some load to push the rings into the cylinder walls and bed them in. Reving it up is no big worry but keep it reasonable for a little while. And yes, vary the throttle level to vary the load.

[brveagle]

If you've done all this work, why not just wait and get the valves in? Most shops in my area even stocked the right size and traded me for them.

And i'd break it in for atleast 500 miles, nice and easy. Let the rings seat.

[Dave8338]

As far as break in on the new rings, on the drag engines (cars), I'll run them on the tuning stand for 2-3 hours at 2500-3000, unloaded. It does two things: 1. gets the engine up to temp and maintains it to allow the rings/walls to heat and seat in together. 2. Allows all new gaskets to seat and expand to the mating materials.

Don't push the revs as more won't help. Don't lug the engine as temps usually fall and you don't want cylinder wash as it negates your intended goal and can shorten the life of the rings / hone.

Once you are done with the break in...CHANGE OIL AND FILTER. You don't want any particulate material in in the oil as it will have a grand time with the oil pump and the breaings / bushings / valve seals.

[bwringer]

It won't hurt a thing to run the engine with those valve clearances.

I change the oil somewhere around 500 miles, and re-check the valve clearances and re-torque the head bolts, then change the oil again after about 1,000 more miles. Some people might opt to add an oil change at 100 miles, too.

During break-in, just use inexpensive 15W-40 oil intended for diesel engines. Save the expensive stuff for later.