EC250 Noise and Smoke

[Viv]

I have an 03 EC250 and over the last few runs out there has been a rumbling noise at engine speed.

This has become louder and louder even with ear plugs in. On the last outing the bike also started to smoke a lot - more grey than the usual blue so I headed for home taking it easy. By the time I arrived the noise was really bad but the bike still ran great.

Took the engine out and expected to find a failed main bearing and oil seal. However, the mains and big end are ok but the PV actuator arm (item 35 in the 'fiche) where it fixes to the PV itself has broken. A bizarre failure and that must have happened just as I arrived home otherwise I think (hope!) I'd have noticed.

So all good and less difficult to fix than the bottom end. But what doesn't make sense is why there was lots of smoke.

Do I have more than one fault to fix?

Viv

 

[Caravan Monster]

Have a look at the powervalve itself. If it is coked up, chances are the rumbling noise was the actuator fighting to turn the valve. It's easy to work on and the bearings are cheap if they need replacing, although cleaning it takes a while.

On a related matter, I recently found out that (in the UK anyway) 2 stroke oil labelled 'synthetic' means semi synthetic. Having changed to actual fully synthetic and running a slightly rich mixture, I found the powervalve stays cleaner and runs much quieter than it did on semi synthetic.

 

[Viv]

Thanks. That's a good top tip.

The PV is free to move and the bearings seem ok so hopefully the PV cam just failed through fatigue. Just have to put it back together to see if there is another problem.

I've been using Motul 710 for a few years and all seems ok with low smoke, apparently minimal wear etc. I've done plenty of 200+mile days on this bike and otherwise racked up lots of hours without issue until now!

Viv

 

[Viv]

It turns out that the cage on the ball main bearing has failed. That does make more sense considering the symptoms the bike had.

I might need to give the Motul 710 a good kicking.

Does anyone know the sizes for the crank seals?

I've searched on here without success.

Viv

 

[Harry]

As fitted to my 02 EC300

ITEM BRAND PART No
1 x SMALL END BEARING INA KBK 18x22x22
1 x LHS CRANK BEARING SKF NJ206ECP - C3
1 x RHS CRANK BEARING SKF 63/28 - C3
1 x LHS CRANK SEAL KOK 20x35x6 - VITON
1 x RHS CRANK SEAL KOK 38x52x7 - VITON
1 x COUNTERSHAFT BEARING SKF 6305 - C3
1 x COUNTERSHAFT SEAL GENERIC 30x40x7

 

[Viv]

Top man!

Thanks

 

[70455]

I am looking for these seals too. Are they double or single lip? There are viton pieces on ebay for $6 each, is this right?

What source are you using for the seals?

Thanks

 

[Viv]

Single lip viton. I bought them locally but online bearing places sell them as well such as simplybearings.co.uk


Viv

 

[(F5)]

Nothing wrong with Motul oil, but bearings fail after a while esp on an '03. Could try the 800 which is premix only version. I use the 800 on roadrace bike that spins out to 14k & think it is great, but at that level most of the oils are great, but this is where oil debates start raging with little fact & lots of emotion involved.

 

[Viv]

As fitted to my 02 EC300

ITEM BRAND PART No
1 x LHS CRANK BEARING SKF NJ206ECP - C3

Note that this bearing has the plastic cage and it is the same as the type fitted to my '02 250 originally.

Viv