Hey guys, so I did my 351 install earlier this year, and my SECOND attempt at it went off without a hitch.

Bike is broken in at over 200 miles on the new cyl and pulls great after throwing in the tm36 and 15/39 gearing at the same time.
I love it and Bill has been great to speak on the phone with.


Anyway, my bike is burning oil.





Started happening after my 351 install.

My bike is the 09sf with over 4000mi on the odo.
I run stock clutch, use Valvoline 10w40 for motorcycles, and when I did the big bore, I checked valve clearances and saw they were in spec. My piston rings were arranged as per the klx 300 manual.

I did two oil changes after the first fill-up following the 351 install (currently at over 200 miles) and dont see suspended particles in the oil anymore, but the oil is BLACK, and the filter gets very black too.





The rear of my pipe used to be just metal, now it's covered in oily soot. I feel it greasy in my fingers.
The engine also gets VERY hot. I run Engine Ice as coolant, and the engine gets hot to the touch on any warm or cold day, without setting off the temperature warning light, and without turning on the fan, as I've never seen either (so tell me if this is normal.)


I've had to top off my oil every couple rides because the oil levels drop.
Oil drops about 1/3 of the window level every 40 miles.
So after 2 or 3 comutes to work and back, my oil level is from full to nearly empty.
I ride exclusively on the road. It's my weekend and occasional commuter bike, usually tearing up the neighborhoods or cruising down backroads at 65mph at 6500rpm.

I see no leaks outside the engine or around the banjo bolts, so it's some sort of leak in the cylinder then.


I'm probably going to have to tear into the engine for the third time to fix this, which I'm not looking forward to, but I dont know what I'm looking for.
Do I check piston rings again? Do I need to check valves? valve seals?

Did I not break in the engine correctly?

Please help guys.
Thanks.

 

First off-200 miles hasn't even let the rings seat yet so give it some time. If you are still convinced that you have an oil consumption issue do a leak-down compression test to put an actual % on blowby. I would monitor if you need to add oil and keep a record-my 351 has n o issues with temps but it is designed to operate at 165-185 deg F. Most modern gas engines routinely run @200 deg so there really isn't a problem unless it's boiling over. I understand being a bit paranoid-my 351 developed a rod knock and I had to put a new crank in-Bill helped with freshening the cylinder and parts-stand up guy. Now get out there and thump!

 

I hardly ever top mine off, so I think you have a problem.

If I was going to start somewhere...
1. See if you can get the crankcase to breath, sometimes crankcase pressure causes blowby. I used the blockoff on the emissions from BB and can't really remember how I addressed this.
2. Hate to say this... did you put your oil ring on upside down? (i don't even know if there is a top or bottom, but I suspect there is)
I don't think engine temps or valve adj is going to effect this at all.

Compression Rings
Although in many cases most compression rings appear similar to the mechanic installing them, there are, however, many subtle design changes which dictate how the ring is correctly installed.

Not only must the ring be installed with the proper side toward the top of the piston, but it is also imperative that the ring be installed in the proper groove.

Rings installed in the wrong groove or wrong side up can lead to excessive oil pumping, excessive blow-by, and in some cases completely dry up the bore, causing ring and cylinder scuffing as well as accelerated wear. Any of these problems, of course, constitute a failure as far as an engine overhaul or rebuild is concerned.

 

Your engine isnt just burning oil, its burning a LOT of oil.

I completely disagree that its not broken in. 200 miles should be more than enough to seat the rings if you rode it right (lots of load). Even if you didnt get on the gas and rode like a grandma it shouldnt burn that much...

Think about it...does ANY brand new bike burn a quart of oil in 120 miles??...HECK NO!!!


Few things before you tear back into it:

1. What ring gaps did you use?
2. Did you install the rings the correct direction?
3. (unlikely) did you block off the emissions? If you did not use thread sealant on the AIR valve bolts (where it attaches to the head) it could theoretically allow oil into the exhaust-but i doubt that much.

My temps only went up 10-15 degrees at most (and only at highway speeds, all other times no different than usual) but I have a plated cylinder so its a little different. MY 330 burned just a tiny amount of oil in the first 50 miles and burns nothing after that.

 

Thanks for the replies guys.

I have a theory on what might be wrong.
When I did my 351 install, I used a hose clamp to clamp the piston rings around the piston and allow myself to slide the cylinder over it. I'd remove the clamp shortly after putting down the cylinder HOWEVER, I may have left the bike sitting for a couple weeks waiting for more build parts to ship and the clamp was down tight on those rings during those weeks.

The rings may have stayed compressed and now no longer don't hug the wall properly, if they're that easy to bend I guess.

I'm going to contact Bill about this issue and see what he thinks. Lesson learned if it's true.
And then I'll ask him about getting new rings, gaskets, and maybe a ported head while I'm digging myself into this hole.

Wish me happy wrenching.

 

I would think it unlikely that the hose clamp would do any damage because when the piston is in the cylinder there is very little clearance and the rings would be expanded against the cylinder. They are designed to work that way.

 

Ditto canklx

 

Thanks for this. That's one thing eliminated.

To answer a few more questions, I installed my 351 piston with the rings how they were when the kit came in.

The rings were already placed on the piston, so I left them as they were and just rotated them to match the alignment here:

source: https://livetorideblog.wordpress.com...l-a-diy-guide/

And I did use the blockoff plate that Bill supplied with the kit.


I've yet to contact him, but I will soon.
Here's to hoping the inside of my cylinder and my piston won't be too gunked up and beyond reuse on my THIRD teardown and rebuild of this bike.

 

Did you get this figured out? First 200km my bb351 burned no oil. Now I am burning what I think is a lot with some white / Grey smoke at times. My pipe is also black at the tip and dark brown at the corner of my license plate.

My last oil change the oil was dark dark Grey, not black or golden like expected.

I also followed the piston ring diagram.

 

Hey guys, what is the function of the block-off plate?

qxangelxp, is the crank case breather still functional? I'm thinking crankcase back pressure.

Ride on
Brewster