I have a 1211 Custom with Vance and Hines shortys re map (so the dealer said) and joker machine air cleaner.

When the bike is cold let out clutch give some throttle bike takes off.
perfect from there on upper end real strong.

Bike gets Hot it takes a lot more throttle (fuel)
to smoothly take off from a stop. Again after take off bike runs great
thru all the gears upper end is great.

I get about 45 mpg plugs are grey so I think it where it should be.
This is my first Harley so is this a Sportster thing? real concern
is the clutch I dont want to burn it out by long take off's.

Thanks for any help.
Charlie

 

Think what you might be experiencing is differing clutch bite in colder temps.
I can't tell you with Harleys as I've only ridden in FL, but any one of my manual cars I had in colder areas would always have the clutch catch earlier before the engine warmed up.

Dunno if that all holds true with HD's or not, but I wouldn't worry too much about the clutch. It's not a dry clutch and only stories I've heard of them burning up is from constantly riding it.

 

Thanks. Comming from a 1700 roadstar that would walk at 5mph all day long
this bike is not smooth off the line but perfect when it gets rolling.

 

Yeah, one thing about the sporties is that they don't like to crawl. Best manuever to learn for those low speeds is clutch feathering. It seems like it'd be bad for your clutch, but I've clocked over 8,000 miles and haven't had an issue yet!

 

If it is stumbling at low RPM you are probably to lean in that part of the map. This would be more apparent after the engine is hot.

Kevin

 

I might have caused the problem myself. I tightened the play in the
throttle cable that was loose and the bike tookoff better from stop.
Could a loose throttle cable cause a problem from stop with EFI.

Charlie

 

+1

Unless you are getting clutch slippage, I agree with this as a likely issue.

When the bike is cold, before the O2 sensors are up to temp, your bike runs in an open loop mode that is a bit rich. Once the sensors are up to temp, your idle and off idle AFI is controlled by a closed loop mode that has its target set pretty darn lean.

Now, I know you have a tune on your bike, so that may change things, but I agree with DK that if your bike is stumbling at off idle throttle application, it sounds like you are a bit too lean.

Get a CUSTOM tune, they are worlds better than preset maps. I have never and will never put a preset map on my bike.

 

I find exactly the same on my 883, When the choke (enrichener) is out on a cold engine, the bike leaps away. By the time running temp is achieved and the choke goes in, acceleration needs a lot of throttle. I have not had the machine for that long and thought it was a Sportster thing. Perhaps I ought to have the jetting checked. I do quite a bit of clutch feathering but am not always confident to be first away from the lights as I have on Jap bikes. Love it to bits though - the engine sounds so strong as revs rise through the mid to upper range. Slow riding is not easy, I agree. That's why I like fast!!