Possible Engine Mod on my bike???
Possible Engine Mod on my bike???
I bought a pre-owned 2010 Street Bob. It has the same engine as my boyfriend's Crossbones, but when I start it, this bike is like a 3yo with ADHD, it just wants to go. It has aftermarket pipes on it, but we're not sure what kind since there doesn't appear to be any stamps, but we're pretty sure it's had either a chiptune or some sort of engine mod. When I start it, you can see the horn cover jumping. I've seen other Street Bobs running and they don't do the same thing. Any idea what could have been done?
Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
Unless there's a bolt-on tuner like a PowerCommander or FuelPak visible then there's no way to know what's been done to the tune. You would have to get a tuner that programs the ECU like a SEPST or TTS and download the tables off the bike and inspect them.
Actually not the same engine. The softtail twin cam is counter balanced so it would be smooth at idle. The Dyna has a non-balanced rubber mounted engine. They hop around more at idle, it is normal. If it is excessively shaking you may just need new engine mounts (even on a 2010). But different cams could make the engine lope more as well.
Its definitely shaking more, I saw a street bob the other day and waited for him to leave (yeah,i know, stalker) so I could see if it reacted the same was, it didn't. I called the dealer to have him check the records, we'll see if he finds anything out. If not, I'll have to check those engine mounts. Thank you both!
Cruiser
Joined: May 2011
Posts: 129
Likes: 0
From: Texas
I had a similar experience when I traded my fat boy in and got the new SB. The rubber mounted engine shakes a lot more. Just enjoy The good vibes! You can also make fun of your guy because your bike will smoke his! Ha ha.
Club Member
Joined: Dec 2007
Posts: 4,192
Likes: 168
From: Knoxville, Tn
Engine Shake
I've done 2 different set of engine mods on mine and it really shakes. I've put new motor mounts on it and it doesn't change.. also loosened the mounts up ,let it idle and then tightened them down again and it did nothing to stop or slow down the shake.
I have a feeling that my flywheel has slipped just a hair but I don't want to tear down the bottom end to find out.
It maybe something you have to live with unless you tear the whole thing down.
I have a feeling that my flywheel has slipped just a hair but I don't want to tear down the bottom end to find out.
It maybe something you have to live with unless you tear the whole thing down.
Trending Topics
Shimming the mounts to get rid of the preload also helps, I did this on mine when I changed the front mount.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
It seems to be a smooth ride, honestly this is my first bike, so I don't have anything to compare it to. My dealer called back yesterday, nothing was ever mentioned about any modifications, but he said he really doubts it's the engine mounts since the bike only had 21xx miles on it. For now it looks like it's going to remain a mystery and I'll chalk it up to a personality quirk. Granted, it's one hell of a personality quirk! (I love it!)