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Arjan van Druten

Is the Yamaha WR400 (2000) Carb resistant against ethanol (5% - 10%) in modern fuel

9 posts in this topic

I recently discovered the news that normal Euro 95 (Europe) fuel contains 5% ethanol (since 2013). I also discovered that this does dramatically change properties of the mixture and may need adjustment in the Carb jets, etc...

 

My motor was not running very nice (just bought it) and I decided after messing around with it, to change to some special fuel from Total (Excellium 98, without Ethanol) and guess what...All problems I had with the engine have almost disappeared!!!

 

However, I noticed some sludge in the Tank (l suspect it comes from the Euro 95, ethanol) and noticed that the fuel valve had a internal leak. I understood that this ethanol crap does react with water and/or oxygen or something and may seperate from the other parts in the fuel (very quickly the fuel gets old) and creates this sludge...and may therefore block small channels in the Carb. Even worse, ethanol seems to attack some specific rubbers (natural rubber and butyl rubber) - hence the leak of the valve?-, other rubbers are not prone to this attack (Viton and Nirtil Rubber). 

 

Some alarming news came from companies dealing with older bikes, claiming that since this ethanol was introduced their repair shops started to get full of bikes with serious fuel related problems...They even started a society to stand up against the acts in Brussels to stop the increase to 10% (related to politics and environmental, global warming stuff...)..- they seem to have never investigated the effect on Older bikes or Cars!!!

 

Anyhow...my question is, does anyone know if the Yamaha WR400F, equipped with the FCR carb Keihin FCR-39H contains these sensitive rubber materials (butyl rubber or natural rubber) in seals / gaskets etc...Has anyone had problems with the additions of ethanol to the fuel?

 

Thanks for sharing your experience!

 

 

 

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No, the rubber is fine. There is no 'real' rubber in any FCR carb.

The rest of the carb is not so lucky....especially the brass components.

You MUST treat your gas, or plan on de-corroding the inside of your carb every few months.

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No, the rubber is fine. There is no 'real' rubber in any FCR carb.

The rest of the carb is not so lucky....especially the brass components.

You MUST treat your gas, or plan on de-corroding the inside of your carb every few months.

 Thanks Krannie,

 

Thats good to hear!

 

But How do I de-corrode the inside (brass) components? Once correded, there is no way back I believe?

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 Thanks Krannie,

 

Thats good to hear!

 

But How do I de-corrode the inside (brass) components? Once correded, there is no way back I believe?

 

Elbow grease, Soaking in green-solvent (no petroluem solvents) will fix all but the most troubled carb.

Remember DONT' USE automotive carb cleaner on any MC carb. 

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Elbow grease, Soaking in green-solvent (no petroluem solvents) will fix all but the most troubled carb.

Remember DONT' USE automotive carb cleaner on any MC carb. 

 

Ok, just bought a can of automotive carb cleaner....Good to hear this Caution just in time!!!!

 

With green-solvent you mean for example just  "normal mild soap"?

And elbow grease means just "hard manual work... " ? (I am Dutch, so had to look up these expressions :-) ).

 

- I also have an Air Pressure Gun (1-12 bar) I want to use... This is  Also Ok (@ ? Bar) I assume?

 

- Furthermore, I have a ultrasonic cleaner that I want to use....Any experience with this?

 

Thanks!

Arjan

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Simple green, spray brake cleaner (low volatility spray solvent), kerosene, gasoline all work fine.

Small doses of 'real' carb cleaner are fine if you flush it out immediately after (EG: accelerator pump nozzle)

 

Air pressure works great

 

Ultra sonic works great.

 

Don't use pipe (smoking) cleaners.

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simple green works great if its available euro land

Haha, no not really in Euro Land, But found a dealer in UK land and they deliver in Europe...Seems good stuff, also certified to some aerospace standards...

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