DN-01 running on one cylinder

Carl

New member
When I bought the bike some 2 weeks ago it would run just fine. Then some days later, I noticedd occasional misfiring of one cylinder when idling. Recently I took the bike out for a trip, and it ran on one cilinder most of the time. When you rev it up it suddenly starts to fire both cylinders. And now it stops at idle speed (it reverts to single cylinder mode then ;-)), and it is very difficult to start it. The bike has been standing still for a long period of time I guess. I replaced the battery, and checked the (original) sparkplugs for wear. I added a cleaniing additive with the fuel - but that didn't solve anything. Does anybody have a clue? Currently there is about 9000 miles on the tacho.
 

Knob

Active member
Site Suporter
I generally dislike to repair bikes by the Internet, but: first thing CHANGE the both spark plugs to new ones. Right plugs are NGK SIMR8A9.
And change the plug caps, those are known on DN to be often faulty. You can use NGK VD01F model of spark plug cap, it has less resistance in it and this is a good thing about making spark. And is cheaper than OEM.
Also check HT wires coming from ignition coil are not loose.
If this will not help, then in case of FI problems better get help from some known good repair shop. Without special tools you can not fix the FI issues at home.
 

Gizmo

Active member
Site Suporter
I generally dislike to repair bikes by the Internet, but: first thing CHANGE the both spark plugs to new ones. Right plugs are NGK SIMR8A9.
And change the plug caps, those are known on DN to be often faulty. You can use NGK VD01F model of spark plug cap, it has less resistance in it and this is a good thing about making spark. And is cheaper than OEM.
Also check HT wires coming from ignition coil are not loose.
If this will not help, then in case of FI problems better get help from some known good repair shop. Without special tools you can not fix the FI issues at home.
As Knob said, the caps have been a BIG problem area for quite a few riders. Just follow what Knob has said to do and you should find/fix your problem!
 

foxdie

New member
If it's any consolation Carl, my dino has just recently started misfiring too, exactly the same symptoms as yours!

It started with an occasional misfire, now it's hard to start the bike unless I hold the throttle a little, at which point it intermittently kicks that cylinder back in and the engine speed jumps up. This would happen every few seconds or so.

At first I thought it might have been a bad MAP or IAT sensor, or even bad fuel. After a bit of testing I've found it to be the front cylinder not always firing. After unplugging it I noticed there was very little difference, if I plugged that back in and unplugged the rear then the bike wouldn't start at all. I did notice that whilst running with the front cylinder disconnected, the red NGK-branded spark caps was occasionally arcing out to the cylinder head through the side of the spark cap, not the bottom where the plug would sit (which I thought was weird).

When I first got my dino at circa 17,000 miles on the clock 5 years ago it had this same misfire. The nearby Honda specialist (luckily walking distance) replaced the caps with red NGK ones and the bike has run fine on those for 4-5 years (albeit only covering 2500 miles in that time).

I'm gonna try replacing both caps and plugs as per Knob's advice and report back if this fixed it for me.
 



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