Missing at low speed

[saabster]

When I start my 96 1100r cold it does fine. Then I drive about 3 miles to work and let it cool for about 1 hour. Then I start it up again and it seems to run rough (miss fire) until I get up to about 3rd gear. Then it is fine even after I slow down again - no more misses. Anybody have any ideas?

[rph802]

I'm not a mechanic by any stretch and I dont even play one on TV but 3 miles doesnt seem like a lot of time for the oil to warm up properly and cover the necessary parts. Do you let it idle for a while before taking off?? Have you switched to Synthetic oil??

Craig

[beekstersocal]

dont go slow

[leno]

When I start my 96 1100r cold it does fine. Then I drive about 3 miles to work and let it cool for about 1 hour. Then I start it up again and it seems to run rough (miss fire) until I get up to about 3rd gear. Then it is fine even after I slow down again - no more misses. Anybody have any ideas?

Sounds like a fuel glitch, possible vapor bubble or water in the system. One question I would ask is this the same route or does it happen on any 3 mile trip and 1 hour lay off. Also whats the temp there now?

[CycleRob]

saabster,

With your `96 bike's year and the cold climate your riding in I suspect the ignition system. Low speed misses point to plug wires. It will redline OK without a misfire, but will misfire once every couple seconds if, for example, you use 1/3 throttle at 2,700 RPM. If your R1100R still has the original plug wires - - - it's beyond time to replace them. If they are fairly new, they can also be permanently damaged by pulling on the engine heated wire. You might think that the easiest shot is to replace only the sparkplugs, but aged/damaged/cracked plug wires will ruin them too in a month or 2 when they require more voltage to fire them.

Another slight possibility is water in the fuel, but the duration is more consecutive misfires, whereas a bad plugwire will missfire maybe 1 time per 500.

[socalrob]

CycleRob,

What do you consider a prudent replacement interval for plug wires? Would it be the same for both sets of a plugs on a dual spark?

Great post/reply BTW.

Rob

[CycleRob]

socalrob,

There are a lot of variables that will influence the service life of plug wires:

-- Quality of the original wire's insulation.
-- Type of wire (carbon paste or solid wire).
-- Operational heat, water splash and especially MOVEMENT in normal operation.
-- Damage from rough or improper handling by the service person[s].

My wife's 4 year old Ford Escort (replaced by a Civic !!) had bad wires at 80K miles. It also had only a low speed miss that drove me nuts until I spoke with a Ford Tech, at length in his workstation, at the wonderfully cooperative dingle Milham Ford's 24hr Service Dept in Easton PA. Apparently electronic ignitions malfunction only at low rpm's when the wire's internal resistance gets about 50% higher. My digital multimeter measured one of the 4 wires with just such a deviation. The Ford parts man said the relatively early failure was common with the OEM wire set so I purchased a Lifetime wire set from Advance Auto Parts for about $20. Problem solved.

BTW, an ohmeter check of the plug wires would be a good addition for the supertech owner to add to the yearly inspection. It will at least confirm a functional breakdown of the carbon conductor - - - but will NOT reveal breakdown and failure of the wire's insulation and possible arcing to ground before the power gets to the plug. Also, DO NOT replace carbon wires with solid wires if there's an electronic ignition. The wire's resistance is necessary for the system to work properly without damage.