I have an 08 FXDB Street Bob and I have been having random episodes, mostly on the highway, where I will be cruising with the throttle in a fixed position and the I will feel the bike lag a bit like the rpms are dropping. I will then roll on the throttle to give it gas and there will be little or no response, or it will be delayed and eventually the bike will lunge forward. When it happened today I pulled in the clutch and dropped down a gear, let out the clutch and the bike lagged backward almost like I let off the throttle with the clutch engaged. The first time this happened I thought it was due to bad gas so I ran a can of seafoam through it. Now I am not sure since I've gone through several tanks and this has happened 2 more times since. The bike has about 14,000mi so I don't think it's a clutch issue, but then again I have never had a clutch go bad on me before. The first time this happened I was riding for maybe the first 5 minutes of the day; it also happened after 1.5 hours of riding as well, so hot or cold it doesn't make a difference. The bike seems to run fine after these random episodes but I have no idea what is causing this. Any insight or help would be greatly appreciated!?

 

Fuel pressure issue? IAC needs cleaning? Fuel filter clogged? Does sound like a fuel issue though.

 

If there was a problem with Fuel pressure or IAC wouldn't it cause a constant problem? It just seems weird to me that this happens sporadically and intermittently.

 

Agreed , does sound like a fuel issue , maybe a faulty fuel pressure regulator . If you end up going in your tank , might as well change the hose and filter too , probably plugged , especially if it's still original .

Cleaning the iac is easy enough to do , just spray some tb cleaner while cycling the ignition , ( do not start ) , it will open / close the pintle and help get more crud out of it . Give this a shot before tearing things apart .

Check for error codes , doubt there are any , but you never know .

Good luck !