Spark plug diagnostic

[thegunner76]

Nice advice. I'll definitely will do the fuel system cleaning and change the gaskets. Regarding the valve adjustments, my own hands will do for now


Im no expert, but when you are talking about the fuel itself I think you are on to something. I live in norway, and the government mix at least 10% bioethanol in the petrol which ive read isnt kind to old engines. The common octane here is 95, but I believe you can get 98 at some stations. The octane levels isnt completely comparable to US values, so when you say 93, I guess thats equivalent to our 95 (more or less). Im 95% sure    the previous owner used regular 95 octane...

Which leaves me to the consumption that Im looking at wrong spark plugs together with ethanol petrol on a old bike with the need of a valve adjustments. Thanks. Again 

[ducpainter]

I think Norway uses the same octane system as the rest of Europe. If 93 is the lowest available use it. If 91 is available I believe it would be adequate.

We have ethanol in our fuel here in the US, as well. It causes it's own set of issues, but octane isn't involved.

The plugs that were installed were not the projected tip type that Ducatis need. I bet it will run much better with the correct plugs. The Techron will help remove the deposits from the pistons. I would use it as recommended on the label, and avoid all other fuel supplememnts.

[Howie]

I think Norway uses the same octane system as the rest of Europe. If 93 is the lowest available use it. If 91 is available I believe it would be adequate.

We have ethanol in our fuel here in the US, as well. It causes it's own set of issues, but octane isn't involved.

The plugs that were installed were not the projected tip type that Ducatis need. I bet it will run much better with the correct plugs. The Techron will help remove the deposits from the pistons. I would use it as recommended on the label, and avoid all other fuel supplememnts.

I wouldn't be so quick to recommend less than 95 RON for that bike Nate.  You may be correct, but I have to say may.  There really is no equivalent between AKI numbers and RON.  AKI is RON+ MON divided by 2.  The problem is the answer is not mathematical.  To save a lot of typing, https://www.differencebetween.com/difference-between-ron-and-mon   We came up with AKI back in the late 70's or early 80's, not sure.  There was a big push to improve fuel economy.  One of the ways they accomplished this was by increasing volumetric efficiency at the relatively low highway speed on our EPA test. This led to ping at light throttle just after an upshift instead of the usual traditional ping from lugging the engine in a high gear.  Also, the famous General motors claim a little knock is good.

That SR4R is higher compression than the S4, 11.5.  In the US it runs fine on regular, but maybe not in Norway.

[ducpainter]

Point taken, Howie, but I still recommend the minimum octane to prevent pinging. I got the conversion off the net.

I'm no scientist, but if 89 works in the states, whatever the equivalent is in Europe should work.

[koko64]

+1 on 95 RON to be sure. Consider 98 in summer (30°C  +) and track days if the compression is higher than 10.5:1 in a big bore. I guess 30°C is rare up there, so 98 may be unecessary.
After reading that link it confirms in my mind why some bikes may run well in cool weather with a low octane fuel but struggle in hot temps unless the next level higher octane fuel is used. That's consistent with my experience in a country with the RON rating and hot summers. Our fuel in Australia is the poorest quality in OECD countries however, so maybe my experience is worthless to those in the EU and US.. In much of the EU, 95 RON is the base level fuel as reflected in the owners manuals.