Engine missing at start up and sometimes on the road

[rocket51]

Approximately 3 weeks ago, I noticed engine running ruff during startup but smoothes out within a minute. I also smell gas in exhaust. I put some engine cleaner in and then I started having stalling while going down the road 50-70 mph, the stalling was bad enough that I thought it might die but it never has. When I kick the speed up to 75 and above the stalling is gone. The engine cleaner has helped the ruff start up but seems to make road stalling worse.

I have 29,000 miles on the bike and it has never had this problem before. I haven't replaced the fuel filter but I don't think that is the cause, though it might be. Also I have never adjusted the valves but I don't think that is the problem either. I likely need to sycronize the throttle bodies but don't know how. The gas smell makes me think the gas is to rich. Possibly I need to do a retune. A friend did Wayne's tune on the bike 12.000 miles ago and it has been great till now. I did the 12 minute tune but it didn't help. Most of the time the bike runs strong but when it starts stalling on the road, this gives me concern.

Anyone have any ideas of what my problem might be?

 

[ScottishR3T]

From what you've said I would be checking everything from the coils to the spark plugs.

Maybe the plugs need replaced.
Maybe a poor connection on one of the plugs.
Maybe an HT lead is shorting somewhere.
Maybe a coil pack ready for chucking it.

The rough running and smell of gas makes me think the spark circuit. As you said though, could be a tune that's gone weird. That has been discussed on the forum recently, a tune that's been good for years then goes wrong.

Not really a solution for you! If I had those symptoms it's where I would start though

Good luck .

 

[El Toro Rosso]

Maybe you've just gotten into some bad gas. I know it smells rich, but if the gas doesn't ignite on the spark, out it goes. Plugs/wires/coils are always a good thing to check too when stuff goes sour.

 

[warp9.9]

Check the low tension leads going to the coils Green and Brown I believe. The tend to get loose and sometimes corrode. Clean the terminals apply some dielectric grease and re-crimp them with a pair of needle nose pliers. They should go on snug. It could be one or more is loosing contact and the plug is not firing every now and then which will make her seem like a sparattic miss and you will smell the unburnt fuel in the pipes. Easy fix but #1 coil pack is the hardest to get at because it is up front under the neck. So start with #2 and #3 and see if your problem goes away. Usually it is one of them two since they are more exposed to the elements.

 

[rocket51]

Thanks for the suggestions. I know it is not the gas for I have been through probably 10 tanks from different stations since problem started. I put new NGK iridium plugs on about 3,000 miles ago. Warp I think I will start with your suggestion of checking coil wires. If I find the problem I will post solution.

 

[IMFASTTOO]

Approximately 3 weeks ago, I noticed engine running ruff during startup but smoothes out within a minute. I also smell gas in exhaust. I put some engine cleaner in and then I started having stalling while going down the road 50-70 mph, the stalling was bad enough that I thought it might die but it never has. When I kick the speed up to 75 and above the stalling is gone. The engine cleaner has helped the ruff start up but seems to make road stalling worse.

I have 29,000 miles on the bike and it has never had this problem before. I haven't replaced the fuel filter but I don't think that is the cause, though it might be. Also I have never adjusted the valves but I don't think that is the problem either. I likely need to sycronize the throttle bodies but don't know how. The gas smell makes me think the gas is to rich. Possibly I need to do a retune. A friend did Wayne's tune on the bike 12.000 miles ago and it has been great till now. I did the 12 minute tune but it didn't help. Most of the time the bike runs strong but when it starts stalling on the road, this gives me concern.

Anyone have any ideas of what my problem might be?

CHECK the coil connections they corrode

 

[HansO]

if the coils wires check out OK check when the fuel filter was last changed and check the injectors, apart from the ***** of a job pulling them out it doesn't cost to much to get them Ultrasonically cleaned, you will be amazed how much crap can get past the fuel filter which can then block the very fine holes in the injectors causing a disturbed spray pattern

 

[HansO]

CHECK the coil connections they corrode

and put Dielectric grease on them once cleaned

 

[ROCKETHEAD]

One tank of bad gas is all it takes, does not matter how many tanks afterwards. Pull fuel pump assembly, check filter, check coils, check/clean injectors are all sound advice.

4 R3's in past 10 years.
2 fuel filters
1 fuel pump
1 set of injector cleaning

Just saying

 

[IMFASTTOO]

and put Dielectric grease on them once cleaned

YEP I agree