EOC: Clutch Restart Effects on Catalytic Converter - Fuel Economy, Hypermiling, EcoModding News and Forum

FilthyAnimal · 07-20-2015, 04:09 PM

I once read that a clutch restart for my KLR 650 would send un burnt fuel down the tail pipe. This information came out of the owners manual. It stated that when this un burnt fuel came into contact with the catalytic converter, the metals on the catalytic converter would react and burn off of these metals that make the catalytic converter do its thing rendering it useless.

SO, Is this a bunch of BS?

I like EOC, but I do not like using my starter as much as I do. I want to do the clutch restart but I am hesitant due to the information I read in my motorcycles owners manual regarding clutch restarts destroying a catalytic converter.

Boils down to this... Is recommended to do a clutch restart or a starter restart?

Are there reasons other than the catalytic converter to choose one over the other?

MetroMPG · 07-20-2015, 05:59 PM

Good question. I've never read that in an owner's manual!

Don't forget to also consider clutch wear. It's small, but it counts.

I'm not a doctor (I only play one on TV), but my sense is that the brief, relatively infrequent rich condition during re-start isn't a big deal to the cat.

But a persistent rich condition could overheat a cat and burn it out. (This happened to the previous owner of my first Firefly/Metro, who drove the car for over a year with the check engine light on for a failed O2 sensor and burned out both the original plus one replacement cat. Also as a result, he got horrible mileage.)

UFO · 07-20-2015, 06:53 PM

I would think, regardless if the engine is carbureted or fuel injected, there would be no difference in misfires before starting using key or bump. The plugs are going to start firing as soon as the engine turns in both cases.

oil pan 4 · 07-20-2015, 10:26 PM

If the converter clogs implement the permanent solution.

I always bump started the car I had in japan and it still passed their emissions test after 3 years.

deejaaa · 07-21-2015, 01:40 AM

Quote:

Originally Posted by MetroMPG

....I'm not a doctor (I only play one on TV).........

i'm not a sane person(i only play one on tv)
i bump start mine all the time. i think it would only be a problem is if it struggles and pumps raw fuel through the engine. if it starts right away it wouldn't be any diff than using the starter.