Stumped, Need Help...Sportster Running Rough!

[sportshogger]

Yes, thats right. Thats why I was asking for him to report what exactly the leak was so we would know after giving him suggestions and trying to help. I was confused by the running rich statement and then to hear that he found an apparent vacuum leak. I suspect it was something we had mentioned earlier in the post that was probably overlooked or it wasn't running rich at all. Guess we'll never know for sure.

Bodeen

Agreed, it would be nice to hear the outcome as Ive been reading this and scratching my head too.

 

[Jack Klarich]

Now that would explain it. I never included lean angles into the equation, and for me it makes it easier to accept an idea when there is a good reason for it. Tks Brian

Cvcarbs here is a good read on slide carbs, back in the late 70 s Lectron made a good slide carb for H D models, you could adjust the needle by screwing it up or down, I had one that worked real good on a shovel head

 

[sportshogger]

Yes. Since there was no means to measure CO content of the exhaust, the next easy way is to inject air.

To me it sounded like a problem with the carb just flooding the engine somehow (? maybe). But I really know nothing about slide or CV carbs. The theory of why a slide or CV carb is preferred over a conventional carb in an application like this escapes me.

Its a great Idea and Im glad that I had read it right, once again Hoople, thanks for another great tip.

I think that slide carbs have been the prefered type of carb for a motorcycle for many decades due to ability to work at the lean angles that can be achieved on a sporting motorcycle
the cv type carb seemed to appear in the mid 70s and is supposed to work better than a slide carb at varying elevations above sea level

Brian

A few guys I know swear by the mikuni, and when buying another harley thats the first thing theyll add to it, Ive found the cv works pretty well, and they are suppose to get rid of the flat spot charictaristic of the slide. The Mikuni does seem to get rid of the annoying spit back that can sometimes happen,and seems to need less choke.

 

[Jack Klarich]

I think that slide carbs have been the prefered type of carb for a motorcycle for many decades due to ability to work at the lean angles that can be achieved on a sporting motorcycle
the cv type carb seemed to appear in the mid 70s and is supposed to work better than a slide carb at varying elevations above sea level

Brian

A few guys I know swear by the mikuni, and when buying another harley thats the first thing theyll add to it, Ive found the cv works pretty well, and they are suppose to get rid of the flat spot charictaristic of the slide. The Mikuni does seem to get rid of the annoying spit back that can sometimes happen,and seems to need less choke.

Mikuni is a very good slide carb some models have bearings on the slides very tune able kind of spendy tho

 

[BUBBIE]

This thread is going nowhere so lets change the subject.
Speaking of Fishy, BUBBIE what are you holding in your avitar? and what are you standing on to make it look like your standing on your mc seat?

************************************
MY Avatar; Glad you mentioned;
The picture is of my bike and a Wooden Carved Fisherman Holding a Huge King Salmon was taken with bike parked in front to give the affect of THEM riding the Harley..(the wooden carved statues Need a Bigger Bike than mine to fit.)

"South Bend" Washington is A Quaint little fishing village near the Pacific coast,,, Inlet off ocean(a safe harbor).. South of the famous "West Port" fishing capital of Washington..

BEST two-lane back roads to travel..... Not once on the freeway, goes around south coast, across the Columbia river mouth, on a 4.9 mi. Bridge into Astoria Oregon. Now this is HD Country.

Not showing in the pict is 2 other parts of the Tribute; a Huge Brass 3 propeller off a Huge boat,, Prop stands 8' tall then to the right of the prop is a wooden carved woman dressed in clothes of that time;1800's.. to match the fisherman on the left of prop..

This being a Very Proud fishing town along with the display of the MANY who were involved in Military Services, active from the 1800 thru today.. Naming the many who Gave Their ALL. Such a small community but Large in number of Patriots.

Just one of the many nice stops in the road, allows one to reflect on past. Now with the harley there it now reflects on the future.

signed....BUBBIE

 

[fin_676]

I have fitted mikuni hsr carbs to both my big twins as they seem to work better in my environment as it does not get hot here and there is often a high moisture content in the air i had a lot of problems with carb icing with the stock cv carb and found that the mikuni is less prone to the problem i will get a wee bit of backfiring and rough running during warm up in the colder wetter times but only for a short period first mile or 2 but with the stock cv in the same coditions often came to a dead stop even when the engine was hot if it would run long enough to get hot i got a wee bit fed up of sitting at the side of the road waiting for the heat from the engine to melt the ice in the carb so that i could get to the next town then when slowing down again engine would die and wait for the heat to do its work

Brian

 

[fin_676]

Mikuni is a very good slide carb some models have bearings on the slides very tune able kind of spendy tho

Bike cost £6000 was unuseable jan feb mar and some of april and could be a bit tempramental depending on weather for the rest of the year
£250 was a cheap fix to make the bike so much more useable the mikuni carb is a nice and for me worthwhile upgrade
wife got grumpy with me because her bike would be coughing and spluttering when it was raining in mid summer so her bike got a mikuni also now runs great most of the time

Brian

 

[sportshogger]

Cvcarbs here is a good read on slide carbs, back in the late 70 s Lectron made a good slide carb for H D models, you could adjust the needle by screwing it up or down, I had one that worked real good on a shovel head

Thats a good read

I have fitted mikuni hsr carbs to both my big twins as they seem to work better in my environment as it does not get hot here and there is often a high moisture content in the air i had a lot of problems with carb icing with the stock cv carb and found that the mikuni is less prone to the problem i will get a wee bit of backfiring and rough running during warm up in the colder wetter times but only for a short period first mile or 2 but with the stock cv in the same coditions often came to a dead stop even when the engine was hot if it would run long enough to get hot i got a wee bit fed up of sitting at the side of the road waiting for the heat from the engine to melt the ice in the carb so that i could get to the next town then when slowing down again engine would die and wait for the heat to do its work

Brian

Have you tried a shot of Idle boost in with each tank of petrol. Most harley dealers sell it.

 

[fin_676]

As i have never been to a harley dealer might have a problem finding it however i have used silkolene pro fst which was developed by silkolene at the request of kawaski uk to try and find a solution to the carb icing problem with kawasaki motorcycles fitted with keihin carbs
Fuchs Silkolene Powersports Oils & Lubricants
However the mikuni carb works resonably well without any treatments and perhaps gives a wee bit of a perfomance boost

Brian

 

[Jack Klarich]

As i have never been to a harley dealer might have a problem finding it however i have used silkolene pro fst which was developed by silkolene at the request of kawaski uk to try and find a solution to the carb icing problem with kawasaki motorcycles fitted with keihin carbs
Fuchs Silkolene Powersports Oils & Lubricants
However the mikuni carb works resonably well without any treatments and perhaps gives a wee bit of a perfomance boost

Brian

Duralt sold by H D will do the same thing and clean the fuel system ans help keep carbon from building, you can use a lesser grade of gas with this with out knock or ping