One of those DUH moments!

Norm

Vendor
Joined
Aug 26, 2007
Messages
351
Location
Chilliwack, B.C., Canada
Bike
KLR650
STOC #
8030
Absolutely not intending to dispute burning a small amount, but it might be worth considering that computer managed engines can react radically differently to wrong fuel than do not-managed ones. Add diesel to a not-managed system and the higher temperatures required to burn the diesel will result in incomplete or slow burning which usually only results in some power loss. The diesel can provide some upper cylinder and valve stem lubrication as stated. There used to be products marketed as "top oil" back many decades ago which contained diesel or "diesel like" hydrocarbons. The effects of diesel or other slower burning fuels are similar in "not managed" injected and carbureted engines, IME.

Problem is when diesel is added to a "managed" engine, because the incomplete burning of the fuel results in higher hydrocarbons/lower O2 level which is detected by the O2 sensor. The O2 reports higher voltage which the ECU interprets as rich mixture so it reduces injected fuel amount (reduced pulse width). This lean mix burns hotter and slower, sometimes causing combustion chamber temperatures above critical levels.

I'm aware of several pick-up truck engines which were cooked/destroyed due to topping up with some diesel into a gas fueled engine. I recall reports of some others but would have to do some checking with acquaintances. I can ask around to refresh memory if someone is interested.

FWIW, I recommend not riding a "managed engine" to use up contaminated fuel unless one takes precautions such as, possibly, disconnecting the O2 sensor to prevent going into closed loop. I'd not do it at all. Pump out the fuel and burn it in your KLR, IMO. ;-)



A small amount would not hurt, just some good lubrication for the cylinder. But they don't like full diesel.
 
Joined
Feb 16, 2008
Messages
209
Location
Deer Park, WA
Bike
2006 ST1300
I wanted to just read these and move on, but I have to confess to a DUH Moment (actually I thought of quite a few) but the Diesel in the gas engine made me think of the time I filled my F-250 Diesel with gas. I did not know that outside of my home town they can have GREEN covers on the pump handles
 
Joined
Nov 23, 2010
Messages
316
Location
Jacksonville FL
Bike
06 ST1300A
STOC #
8729
Or how about the time many years ago I rebuilt a Can Am 175 getting ready for the Blackwater 100. The bike wouldn't start after the rebuild so I pushed it up a long steep hill so I could roll down the hill and bump start it. While rolling down the hill and bouncing down on the seat to start the bike my buddy is rolling on the ground laughing at me. Meanwhile I am getting madder by the second; seems I must have screwed up putting the tranny back together too because the engine wouldn't turn over when I bumped the shifter into gear. As I was pushing the bike back up the hill to the shop and contemplating killing my buddy and using the bike for a bonfire, he walks out of the shop holding the chain and a gas can!! It's been 30 years and we still laugh about that one.
 
Top Bottom