Smoking Under Acceleration

[phpbiker]

Hi Guys,

I have a near perfect 28K Daytona 900.

The bike makes good power and rides very well indeed.

However other guys following me have noted that my machine smokes under acceleration. It also appears recently to have used a bit more oil than expected. They say it smells oily, but when I smell it smells rich ... possibly some oil. But with modern engines fewer people know what rich smells like nowadays I guess? It certainly doesnt belch smoke if you rev it standing still. Just under load. It will also clean out if ridden hard.

The only thing not yet done on the 24K service list so far is the air filter.
Is it possible this is interacting with an emissions or crankcase breather situation?

I find it hard to believe that a bike that runs so well needs new rings, especially as these machines are noted for high mileages and this one has history that show its a genuine low mileage.

I wondered if anyone else has seen anything like this?

[faffi]

Usually, if it's running rich it should smell not unlike what it does when you fill up at the petrol station. If it's oil, it should smell similar to what your car engine does when warm and you remove the filler cap.

There are several things that could cause the engine to run rich. The carbs wear quickly, making the mixture richer. There are also seals that can go bad, causing rich mixture by making the carbs overflow to a greater or lesser extent. Finally, if the air filter have never been changed, chances are it's clogging up enough to cause rich running.

When you rev it at idle, there is no load and the carbs will barely open up, so the need for air is less and a restrictive air filter won't show up nearly as easily as on the road.

Increased oil consumption can stem from sticking piston rings or hardened valve seals without there being wear in the engine. Clogged up ventilation for the crankcase will also lead to increased oil consumption. This clog can be situated in you air box where the vent hose connects.

[MotT3]

I might be that you where slightly over filled with oil, I used to check mine on the paddock stand and top up..this would give me a false reading (low) and on a run out someone gave similar comments to yours. I now check the oil with the bike flat on the ground (as per owners book) & it seems to need less top ups...so I presume is not blowing the excess so much either ?

Cheers
Mot

[ruamoku]

Originally Posted by MotT3

I might be that you where slightly over filled with oil, I used to check mine on the paddock stand and top up..this would give me a false reading (low)

Crikey, I always check mine on the paddock stand, cheers for that Mot, good luck with the diagnosis php.

[TspeED3]

You probably know this already but since it hasn't been mentioned...

Black smoke = fuel
Blue smoke = oil (and money...)

[KitNYC]

Originally Posted by TspeED3

You probably know this already but since it hasn't been mentioned...

Black smoke = fuel
Blue smoke = oil (and money...)

Ed, it just ain't so. The smoke that came out of my original 955 motor was as black as a tax man's soul, but it actually ran a little lean. It also burned through about 1cc/mile of oil. I also had some friends tell me I was smoking when I got on it with this one, but not to worry because the smoke was black. I checked my oil as soon as they said and saw that I was well down on the dipstick. This has happened with Mobil 1 synth and with Rotella-T mineral.

Cheers,
-Kit

[phpbiker]

What was the conclusion of the 955 adventure Kit?

Anyhow,

I spoke to a UK based Triumph Specialist. Told him about the history of my bike 28K, lots of service documentation etc.

He said that it was very unlikely to be rings or indeed anything in the heart of the engine. I have to say, that having experienced this myself in the past with other older classic bikes, this problem seems different. They smoked on throttle close more than open and they smoked, pretty much all the time. The guide problems I've seen smoked on startup and then stopped. This is different.

I mentioned that my airbox hadn't been done, and he was convinced this and the airbox breather integration was more likely to be the source of the problem. Having seen standard T3's with original internals around the 200K mile mark. The bikes recent eagerness to do, eerrr..(very)high speeds, kinder convinced both him and myself.

I also spoke to a long time friend of mine and ardent four stroke tuning guy. I mentioned my experience of the 15w50/fs going off fast, and he felt also that if it was fully synth it should be lighter, and that this and the heavy breathing and extra oil vapour that might have occured because of it have sped the demise of the airfilter / breather arrangement. Having not seen how it works in this bike (either of us) its possible that oil vapour has blocked the filter to a degree (the bike is rich) and now crankcase ventilation is suffering, or that the old / blocked filter is drawing too much from the cases, causing oiling. There are a variety of possibilities at work here I reckon, least of which is a badly worn low mileage engine that is as quiet as the grave. Although the bikes is down on power, it is still keen, and he felt that the large airbox would be taking care of this to a degree. Only a set of spanners and a day in the garage will tell!

Anyhow, Sprint Manufacturing supplied me with an ORIGINAL TRIUMPH AIRBOX BRAND NEW..for £47 inclusive UK buckeroos (pounds). So, go get yours if you want them, my local Triumph dealer quoted a violently large sum for the same item.

It was his opinion that it should be replaced. Rather than just the element which was nearly as much.

Fingers crossed.

[andrewb]

Mobil1 synth burns grey/whitish....DAMHIK....rip D12

[KitNYC]

Originally Posted by phpbiker

What was the conclusion of the 955 adventure Kit?
<...>

I kept a jug of oil with me on my cross-country trip, then replaced the motor after I got back to NYC. Not because it was using oil, but because I ran it dry after a large piece of something came skidding across the road at me and tore a large hole in the sump. Took it to a bad mechanic who basically stole the "bad" motor, which still ran. The urge to kill is rising strongly, so I will cease to think about that experience now.

The Sprint forum's diagnosis of that motor, BTW, was that it probably had bad valve guide seals, and I know that's a common complaint with the twin owners as well. Now that the replacement has started using oil as well, that diagnosis seems to make the most sense to me.

Cheers,
-Kit

[Sweenz]

Blowing smoke (white to Blue ) under acceleration (Load) is usually a sign of worn rings.
Black or sooty smoke usually indicates an overly rich fuel mixture..

Valve stem seals tend to be noticable at start up with a puff of white/blue smoke from oil drianing down between the valve stems and guides when a warm engine has been shut off and allowed to cool.. I.E. A couple of hours or Overnight !!


Hope you work it out..