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Using oil!
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Got a question for Brian, our TTR guru. I've just got back from a tour of the TET trails in Southern France and Spain. I noticed the oil level had dropped and topped the level up. I've used  1ltr of oil over 1500 kilometres. I've had a quick look this morning and the catch vessel at the airbox was full of emulsified oil. There is a decent pressure of air blowing through the tube when the engine is started up. I'm going to do a compression test to see what results i get. I suppose i'm looking at "blowback" past the rings?? I had the barrel rebored and 1st oversize rings done before i moved to France so i wouldn't expect this to be the problem. Maybe valve stem seals?? I get the little puff of smoke on start up if the bike standsfor a while. But to use this much oil must be piston related?

All ideas gratefully received!!

 

Gruf



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Hi Gruf - long time no hear! How is France treating you? I think you may live near Stephen Dunne?

You have answered your own question pretty much. If your TTR isn't leaking oil then you have worn rings and/or bore. 

I think you can pretty much discount VSOs unless your seals are really bad and the valve guides well worn - unlikely on a TTR. If VSOs worn then you just get a puff of smoke on start up usually. Did you fit new VSOs when the engine was rebuilt?

Also, how many miles has the engine done since the rebore?

It must be very disappointing having done the "right" thing in getting the rebore to now find your engine is losing oil.

I am not going to point the finger as there are quite a few possible causes ranging from a poor or slightly too much of a rebore (leaving too much clearance between barrel and piston) to broken/damaged/stuck rings.

Some engine builders may neglect to thoroughly cleaning the barrel after the honing to get rid of any abrasive left in the cross hatch. Warm soapy water is what I use.

I think you are going to have to bite the bullet at some point and get the engine apart and see what's happening. Maybe a light hone and a new set of rings will get things back to normal.

Brian



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When I did the transpyrenean a couple of years back, I found my bike used oil on long highway thrashes, but none on the trails. A bike mechanic I know said this is normal for aircooled thumpers. Make of that what you will...
The catch vessel filled with emulsified oil is normal - condensation in the crankcases is mashed together with hot oil vapour in the mechanical melee, and makes it's way out to the cyclone in the pulsing air that breathes in and out with the rise and fall of the piston.
Hope you enjoyed the TET. How do the S France sections compare with the Spanish side? Off topic

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mossproof wrote:

When I did the transpyrenean a couple of years back, I found my bike used oil on long highway thrashes, but none on the trails. A bike mechanic I know said this is normal for aircooled thumpers. Make of that what you will...


Every day is a school day!  Thanks for that Simon. I had no idea that was the case so maybe Gruf should hang fire and see if his TTR still uses oil on his local runs wink

Brian



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Moo


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Dan and Jordan also mentioned they have found this as they blast across Europe. During long road sections the bikes have been drinking oil

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Malcolm, Northamptonshire. West Anglia TRF

1996 TTR 250 Raid

2005 TTR 250 Bluey



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my 05 Honda XR250 tornado use to use oil when I done long road miles but around home it never used a drop..
the XR250 tornado had the CBR 250 DOHC road bike motor... CBR owners use to complain about oil useage..
So might be something in the air cooled motors useing oil on 100 kmph high way sections.. after all when

When a air cooled motor gets hot the running clearances in the motor get quite lose is why they don't seize up

at those temps.... look at the machineing specs of a air cooled and water cooled... compaired to a water cooled motor

the bore of air cooled is 1/4 worn out from the start...

 

PS... should have kept that XR... was the smoothest air cooled 250 DS I have riden...

pete..


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-- Edited by petenz on Saturday 19th of May 2018 02:09:51 AM



-- Edited by petenz on Saturday 19th of May 2018 02:14:30 AM

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