Another Burning Oil Question

wall0355 · New Member Joined: Jul 23, 2008 Posts: 4

I also have an engine burning oil problem. I recieved my beautiful '81 xs650 as a complete basket case. I put the engine back together this summer and have had oil problems since. It burns about one quart per 100-200 miles. I am wondering if anyone has some advise. I didn't polish or rough the cylinder sleeves at all, just put it back together.

y question is really this, should I simply get some new rings and hone the sleeves hoping that this should do the job? Or should I spring the money and completely replace the top end with a 750 kit from mikes, getting a tad more power and all new top end parts to ensure that all is well and fitting?

yamaman · Posted: January 14, 2009, 2:58 pm Post subject: Re: Another Burning Oil Question

Old rings are fine if in spec, should have honed the cylinders though.
You could try XSjohns method of a teaspoon of baking soda in the spark plug hole, go for a ride then a teaspoon in the other pot go for another ride. Might fix it up some. Other wise re ring & hone if everything else is in spec.
Could do a leak down test first to be sure, though I'd suspect the rings seeing as you didn't hone!
Cheers

xsjohn · Posted: January 14, 2009, 3:08 pm Post subject: Re: Another Burning Oil Question

Your rings have not seated...sometimes it takes guite a while and if they don't seat right away the cylinders can glaze......a put together which I do all the time can have seating problems.......the last time I recommended a level teaspoon of baking soda in the spark plug hole and turn it over a bit and replace the plug and run it (one cylinder at a time) ....but I don't recommend this any more since I got beat up for it.....but I will continue to do it.....

Since I started using the one way valve on the engine vent my oil consuption has been reduced considerably......Only been a few months and the weather has been colder so I will have more definative results this spring........

xsjohn

jpowell · Posted: January 14, 2009, 4:05 pm Post subject: Re: Another Burning Oil Question

One way valve, you mean on the breather to keep a vaccuum right?

Retiredgentleman · Posted: January 14, 2009, 4:35 pm Post subject: Re: Another Burning Oil Question

Wall0355;
I had a similar high oil consumption problem. I'm now doing a top end re-build. When I started opening-up the engine, I found that the head domed nuts were not tight. I suspect the previous owner had removed the head, but had not done a correct re-torque after running for a while. I found that oil had been seeping between the head gasket from the cam chain tunnel into the cylinders

If you're not in a hurry to open up the engine, you could try re-torqing the head again. Re-torqing needs to be done in stages. The large domed nuts can have up to 30 ft-lbs torque.

Go to www.650garage/engine/modified engines/ leakless assembly. Lots of good info in the leakless assembly.

When an engine is apart, you should always measure cylinder wear, piston to cylinder clearance, lap the valves etc. Valve seals should have been replaced also. Depending on cylinder wear, may only need de-glazing, and not honing.

knightrider · Posted: January 14, 2009, 5:10 pm Post subject: Re: Another Burning Oil Question

john

just out of curiosity, I've never heard of the baking soda trick?!
what is it supposed to do?

xsjohn · Posted: January 14, 2009, 5:21 pm Post subject: Re: Another Burning Oil Question

After putting mine together the last time it didn't want to seat.....Out of desperation and maybe lazyness I figured that a little abrasive in there might help break the glaze.......there is no stone or any real abrasive that will hurt anything in baking soda......so I dumped a bit in and it did nothing.......then I got brave and used a "level teaspoon and the plug color came back to normal soon after that........breaks the glaze enough for the rings to seat........need to turn it over with the plug out a few times to blow the extra out and it will still hold the valves open a bit and will make funny noises but then soon goes away.....then ran the heck out of it and did the other side........

xsjohn

yamaman · Posted: January 14, 2009, 5:38 pm Post subject: Re: Another Burning Oil Question

Retiredgentleman wrote:

may only need de-glazing, and not honing.

What is de-glazing RG?

Retiredgentleman · Posted: January 14, 2009, 7:44 pm Post subject: Re: Another Burning Oil Question

Cylinder honing is used to true worn cylinders and to break the glaze (polished surface) on used cylinders before installing new piston rings. It must also be used to smooth rough cylinders after boring. Most ring manufacturers recommend deglazing; some do not. Check the instructions provided with the new rings for details. The term deglazing is generally used when referring to light honing that simply scuffs the cylinder wall to aid ring break-in.
A cylinder hone produces a precisely textured, crosshatched pattern on the cylinder wall to aid ring seating and sealing. Tiny scratches from the hone cause initial ring and cylinder wall break-in wear. This makes the ring fit the cylinder perfectly after only a few minutes of engine operation

Cylinder Deglazing
Glazing must be removed before the engine is reassembled so that the new pistons rings will seat properly. Glazing is a condition that occurs when the cylinder wall becomes very hard and polished from normal friction with the piston rings. If the cylinders are not damaged or excessively worn, the surfaces can be deglazed.

So, it appears that Honing is also de-glazing, but de-glazing is just that, removing the glaze.

xsjohn

The single most important and final step in honing is to clean the bore well with a small brush using soap and water and then dry and use an oily rag....to remove the dirt and tiny stone fragments from the hone marks.....will spoil your work if you don't.....also found this gif on the correct angle of the hone marks.....

I always hone very lighty on a put together (not bored)....paranoia about loosing cylinder clearance .....too light and seating can become a problem and toooo heavy and you can arrive at excessive clearance........for me I rather take the chance on the light side and soda it if needed instead of honing too much.......spose everyone has their own way......and over jetting can wash the rings and cylinders fast.....and leaving the pistons in the bores and just removing the pins on a good running engine can save the bore and a fresh break-in.......hate it when I forget that......

And after removing the head it is easy learrn a lot about clearances buy rocking the pistons front to back.....very little to no novement and I woud be very hesitant to lift the pistons........a lot and is is probably shot.....lift it......something has to change.......in between is always a head scratcher.......

xsjohn

woodman · Full Member Joined: Oct 12, 2008 Posts: 256

In the mid 60's I watched Smokey Yunick at the Daytona 500 sprinkle Bon Ami cleanser down the carb on a 421 Pontiac. Held it at 6000 on the tach and sprinkled it right down the carb, instant ring seal ! Baking soda seems pretty mild compared to that.

xsleo · Posted: January 23, 2009, 7:20 pm Post subject: Re: Another Burning Oil Question

some car makers reccomend bon ami for cleaning glass. if it can clean glass with out damage then it can't have an aggressive grit content. so it should work for deglazing a cylinder wall with out excessive wear on the parts. i might reccomend an oil change afterward to remove the crud cleaned off and the cleanser.

xsjohn · Posted: January 23, 2009, 8:21 pm Post subject: Re: Another Burning Oil Question

What have I done now with the soda.... Question

.... have heard and seen the cleanser thing.....next it will be sand..... Laughing

xsjohn

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