Break-in procedure??

[newmaac]

Last week I finished re-assembling my top end. I rode to work for several days, to make sure that I had no "bugs" to work out.
After about 150 miles I re-torqued the head bolts.

Friday morning I left to go motorcycle camping for the weekend.
We rode about 175 miles to the campground, a combination of freeway, hyway and some great twisties.

The bike ran well and I had a blast. When we dismounted though, the guy that was behind me for most of the morning mentioned that my bike smoked every time that I would accellerate.

I figured that this was just common to the rings not being completely broken-in.

We spent several hours the next day in some of the best mountain roads that I have seen. Not really knowing how best to break-in the rings, I just made sure that I never kept a constant RPM for any long period of time, I didn't rev too high, and I avoided really lugging the motor.

I found that in the first 500 miles since the top end work, I have used a quart of oil. (there is a slight leak at the tensioner, but almost all of the missing oil seems to have smoked out)

While I had it apart, I had the cyls honed, replaced the rings, lapped the valves and replaced the valve stem seals.

I don't know if this is to be expected, or if I missed something.


Any thoughts?

[prometheus578]

Oil consumption is to be expected, and with it, the slight burning of oil in the exhaust. should ease up and disappear over time. But... in the odd case, could also mean that something went loopy during reassembly. May be too early to tell still, but there's always the slight chance.
Most importantly, now that you've got your first 500 miles done, change that oil.(Little shiney particles of metal in the oil is to be expected... that's why your changing it.

[Pat Kelly]

Sounds bad, you should give the bike to me .

[newmaac]

Hey Pat, that sounds like a great idea!.
Infact, maybe I will hook-up with you guys for the Mt Hamilton ride, and at the end of the day I will just leave it with you. I wonder how much it would cost to take a cab home from Modesto.

Ummmmm...... NOT!!

[trbig]

In my experience, I have noticed that if a motor is smoking during accel... it's "Usually" rings. You could do a compression check. If you have one cylinder out from the others, you may have a problem, but if they are pretty even across the board... just keep riding it, and they should seat up. Maybe ride in the back of the group in the mean time to avoid smoking them out... lol.

Tod

[ccogswel]

Sounds like the rings are not seated yet. What you can do is this, take the bike out on a flat road. One with little traffic would help. Get the bike going about 3-5mph and give it full throttle to about 30-40mph let off and coast down to 3-5mph and again go up to 30-40mph again. Do this about 12 times. This should load the rings and help them seat. Hope this helps. And yes by the way change the oil after 500 miles then 1000 and then do regular oil changes. Make sure you change the oil filter as well.

[cajun31]

It's been my experience with any motor that if you get out on an open straight and get the bike up to let's say 50 then let off and let the bike slow then give throttle and keep an eye to see if you have any smoke. If this proves to be true then the problem is the oil rings not seated or worn. In your case not seated. Of course if during reassembly you didn't get the rings rotated correctly that could be a source of the problem. You stated that you replaced the valve seals. If it smokes only during acceleration then they are probably fine. If the bike smokes when you crank it then they may be a problem.

[DiverRay]

newmaac, Do the flat road accel!!!! That is something that you should have already done. Change the oil, do the accel, maybe on the expressway near your house , and then join us on the ride.
We are going to leave Santa Cruz area, and head over 152, and meet up in Patterson. We will then ride the hill from the valley side, and end up close to home.
Ray

[TopCatGr58]

Mac,

My questions is: did you just hone it, and go back with new OEM sized rings, or did you hone/bore to 1st oversize, and use the 1st oversize rings?? If the first, then the tolerances may be a little loose allowing the oil to slip by easier, since the rings don't have as much pressure against the cylinders since they are a little wider than STOCK with stock sized rings!?
T.C.

[newmaac]

TC, I honed the cylinders, kept the stock pistons and bought one size over rings.
We mic'ed the pistons and cylinders to measure for piston clearance. I don't have the numbers handy right now, but they were within tolerence, but just barely.
My thought was that with the cylinders honed, the end gaps in stock rings might be too large.
I didn't have time to get the stock rings, measure them and run the risk of having to go back and order more.
By buying oversize rings, I was assured that they would be too large, and hence could be cut to fit.
It cost a few bucks, but it saved time.
I bought the rings for about $40, and the machinist charged me $90 to size them. (makes for an expensive set of rings).
I was careful to put the gaps in the proper orientation to each other.
I will assume that I just have a little more break-in time.

Time will tell.
Thanks for your input, guys.

[mro]

I will assume that I just have a little more break-in time

OEM Yamaha manual says something like 1500 miles for break-in for new bike.

Book is in shop tho........ Did mention oil change intervals and throttal limitaions during break-in. Will take a look tomorrow..


mro

[ccogswel]

I was reading the other posts and had a thought. The rings you bought, do you know if they were iron steel rings or chrome moly rings or???? If you have chrome moly rings they take longer to seat then regular rings do. If it was car I say pour a little baby powder down the carb but with a bike I'd say do a compression check now and record it and then compare it to results you get when you have more miles on it. The compression should go up a bit when the rings seat. But this may be wrong on a bike. Someone here should know for sure.