Engine misses, no new mods

[The Bandit]

Hey all, I got a slight problem. I went to go for a ride the other day and barely got down the street before it started missing real bad at about 2500 rpm. I always let it warm up for a few minutes til the cyclinders are good and warm. I've always used the same gas station so hopefully it's not the gas. I bought the bike used and it only has a shotgun exhaust and jet kit (not sure what size jets).

I just got my 2500 mi tune up about a month ago and she's been running great. I ride about 50-75 miles a week, mostly on the weekends.


1. I think I can rule out the gas cap (which is after market) as the air didn't rush in after i cut the bike off and unscrewed the cap. I've tested this a couple times.

2. The spark plugs look good but I used a wire brush on them anyways and check the gap at .40, also both cyclinders are getting spark b/c they're both equally warm after warming it up or after a ride. Could it possibly be the plug wires??

3. I checked all wire connections and non look to be frailed or loose.

I've read about the crank sensor, EHC (what is this?), junk in the fuel lines, ignition....etc but have not messed with any of this yet.

I'm starting with the easiest fixes first and then progressing to the more involved. What do you got for suggestions?

Thanks.

 

[Raywood]

Do you use the enrichener to start it?

 

[Glenn]

Your on the right track. I used the enrichener on my HD to warm the engine and got down the road and started missing real bad - had a fouled spark plug.

1) Spark plugs are cheap - I would replace them anyway just to make sure. You can have a "bad" new plug. Just because both cylinders are warm does not mean you are getting an even or adequate spark. I put new spark plugs in with every oil change on both my scooters.

2) Next check plug wires/spark by pulling spark plugs and attaching the plug wires. Ground the plug and turn the engine over a few times - see if spark is good and fires every time for both plugs. Do this with new plugs - if not working right then replace plug wires. If one plug is not firing right switch plug wires to determine if its the wires, plug, or coil...

3) Is air cleaner clean? Check and or clean the carburetor. If you suspect dirty carb check and blow out the jets or use a little gumout carb cleaner.

4) Check for Dirty Fuel Filter - if you suspect bad gas - drain tank and carb bowl - refill with fresh fuel.


These are just some simple steps I would do first if it were me - others here will probably have better ideas.

If the above did not work I would inspect the electrical system and last engine mechanical, hopefully you will find your problem before you get that far....good luck

 

[Little-Boo]

I don't think that wire brush did your spark plugs any justice. Change them and go from there. :2thumbs:

Carlos

 

[Five Five]

All good responses and it seems like your on the right track for trouble shooting...stick to the simple stuff first.....not sure if you said you replaced your plug wires...but that would be my next choice...

 

[The Bandit]

Raywood: I have never used the engine enricher, the dealer told me all about that and will not. It's warm enough in ATL!

Glenn: i'll try all those tips when i get home tonight, i have back up plugs but didn't think they needed to be changed. might as well, you never know. I'll ground the plugs too and check the spark. I watched the dealer do the 2500 mi service tune and i saw them checking that too. Will do again.

I did leave out one thing, the air cleaner looked slightly gasy/oily. I took it off and started the bike with out in my garage but still did not sound right and would not idle. Not sure if the air cleaner need to be on to idle/run for pressure reasons. I obviously wouldn't run it on the street like that but tried it in the garage.

Where is the fuel filter located? I'm pretty handy around motors but could not find. Is it in-line or in tank? I've been trying to get an '06 service manual from my dealer since i bought the bike but they've been on back order.

OK, I'm changing the plugs first when i get home and then go from there. Thanks for all your tips and i'll keep you posted. Love this site already!!

 

[Glenn]

Raywood: I have never used the engine enricher, the dealer told me all about that and will not. It's warm enough in ATL!

Glenn: i'll try all those tips when i get home tonight, i have back up plugs but didn't think they needed to be changed. might as well, you never know. I'll ground the plugs too and check the spark. I watched the dealer do the 2500 mi service tune and i saw them checking that too. Will do again.

I did leave out one thing, the air cleaner looked slightly gasy/oily. I took it off and started the bike with out in my garage but still did not sound right and would not idle. Not sure if the air cleaner need to be on to idle/run for pressure reasons. I obviously wouldn't run it on the street like that but tried it in the garage.

Where is the fuel filter located? I'm pretty handy around motors but could not find. Is it in-line or in tank? I've been trying to get an '06 service manual from my dealer since i bought the bike but they've been on back order.

OK, I'm changing the plugs first when i get home and then go from there. Thanks for all your tips and i'll keep you posted. Love this site already!!

I was assuming that you might have a fuel filter - if you don't, no problem. Most people just clean out the carb float bowl now and then in lieu of using a fuel filter. Those filters sometimes are too flow restrictive to use on big inch gas gobblers.

OT: When I souped up my Softail, the bike kept stalling out - After scratching my head for awhile, I figured out the stock tank petcock was too small a diameter - replaced it with a larger diameter and fixed the problem.

 

[The Bandit]

Well fellas, she's all fixed up! A pair of 4164's brought it back to life! I took it on a ride and it's running stronger than ever. OK, note to self...do not refurbish old plugs!!

Thanks a million guys! You Rock!

Garrett

 

[The Bandit]

Follow up question, how do i keep from fouling the plugs? i don't use the enricher. I read about shifter at a higher rpm's, maybe 3 to 4k? yes/no? What exactly will foul my plugs?

Ok, time to sit back and enjoy this double tall Jack and coke! thanks again.

 

[Glenn]

Follow up question, how do i keep from fouling the plugs? i don't use the enricher. I read about shifter at a higher rpm's, maybe 3 to 4k? yes/no? What exactly will foul my plugs?

Ok, time to sit back and enjoy this double tall Jack and coke! thanks again.

You may need a jet adjustment:

S&S Shorty Carburetor Adjustments

 

[mobsta]

might just need to readjust your carb

 

[Raywood]

Follow up question, how do i keep from fouling the plugs? i don't use the enricher. I read about shifter at a higher rpm's, maybe 3 to 4k? yes/no? What exactly will foul my plugs?

Ok, time to sit back and enjoy this double tall Jack and coke! thanks again.

You buy the bike new? Just wondering. You could be way too rich on the intermediate jet. Also check to make sure your accelerator pump is set properly.

Also, do you notice any black smoke coming out of the exhaust when you rev it up. Ask someone to ride behind you and verify this also. Will indicate a rich condition.

 

[knucklehead]

Your air/fuel adjustment screw might be backed out too far(too rich) or like they said, intermediate jet may be too big. Check the color of your plugs. Black is too rich, tan is just right, and white is too lean.

 

[The Bandit]

To follow up, the spark plug change was a temporary fix. After a fine dyno tune by Bikers Dream of Atlanta it was determined the main and intermediate jet were a bit too large. They backed it down from a .078 to .076 and .030 to .0295


Thanks Glenn, Raywood and all...