Hi folks, Here's my question. Bike has been running very well since I've purchased it. 1986 Softail Custom. I have added a Crankcase Breather filter to eliminate oil misting out of carb. Stock CV carb is my understanding. Ok.. So this morning it was the coldest I've ever ridding this bike this summer, about 50 degrees. So this morning I warmed up with choke, and noticed a slight hesitation when rolling throttle. No hesitation at all while riding and in gear. When shifting I Like pull in the clutch bump the throttle shift, and go. But I noticed it wasn't quick to respond. I ride about 40 mins to work, so I would assume it would have been warmed up good by then, but again, never seen this happen. I did just fill up with Gas at my usual spot. Am I over thinking, rough throttle when cool out, or something wrong. I have not looked at the plugs yet, but I would assume they are running a little lean. Was going to replace them tonight. On my way home from work supposed to be back up in the 70's so I'll see what happens then when it's warm.. Idea's please? Thanks .. TTD.

 

Would not be concerned if it runs good when warmed up. The air/ fuel ratio is pretty critical to smooth operation. Fifty degrees is pretty cool for September but that will easily make a difference. A 14.7 - 1 Stoichiometry is pretty difficult to maintain with a carb.. Just ease up on throttle snap or a little more choke to the old girl gets her juices flowing.

Could be on a 86 for sure that there is some trash floating around in the old girl's fuel bowl

 

Thanks man, I see how she responds today after work. Maybe she just likes it warm. Did this all the way into work. Only did this around 1st gear, once I got her going, she's good. I will drop some Seafoam in her tonight. Thanks for the comments.

 

Don't waste your money. Not going to help floating junk. And anything strong enough for deposits will take take out pump diaphragm, tank filter screen..ect. Don't put anything in tank but gasoline.

 

Thanks man, I researched a little more, and looks like the dense air, chilly / foggy could be playing a role. I'll report back after my ride home this evening and share, in case someone else has same issue. Hopefully that's all it was.

 

The smaller the motor, the worst is is. My 12HP Rider with a manual choke is willing to go at 90 degrees after start up and choke off. 70 degrees and usually needs an on-off of the choke a couple of times before you can engage blade and roll on.

 

FWIW..... My '01 Springer, with a CV40 carb, is a little cold blooded, even here in SoCal. I always have to start it cold, with the enricher pulled. I have to leave it on about 1/4 until I've ridden about 3 to 5 miles, even in very warm temps. But once the engine is up to temp... it runs like a top, and will start before the engine does a full rotation......

Your issue could be several things, from bad gas, to dirt in the carb, etc., etc. Any of those problems won't go away after the engine is warm..... If it runs well after it gets up to temp.... then it's just a little cold blooded... If it persists after it gets up to temp, then time to do some troubleshooting...

Keep us posted on what you find....

 

Will do

 

Ok so rode home tonight , about 84 degrees. Ran a little better but still hesitated at low rpms. Came home changed plugs , ran a little better ( plugs were white). I let bike cool spray some carb cleaner in the carb wiped a lot of black **** out and then ran great for about 10 mins , then Has slight hesitation when coasting down to slow speed came back but not as noticeable . Lean means too much air, will the idle air mixture screw help? If so which screw is it ? Runs great and no hesitation when out of first and higher rpms . Please advise and thank you

 

Could be several things... SInce I don't know it's maintenance schedule, forgive me if any of these have been done recently...

How long ago did you put a filter on the breathers? Was the black stuff you wiped out of the carb, old oil build up from the breathers...? Has it come back since you cleaned it? I have to admit, I have totally forgotten how the breathers on my old EVO worked... I seem to remember they were more complicated than on the twin cam.... but that was many years and many beers ago... When a problem pops up after I've worked on something, that's the first place I go check.. Could you have failed to block something to the carb and now have a small air/vacuum leak?

It could just be the carb needs a good cleaning, possible rebuilding, and tune up. Usually low speed issues are the mixture screw, pilot jet, or main needle tube are dirty/need adjusting. Here is a link to the CV performance web site. They have parts and a lot of information about rebuilding and tuning CV carbs... Spend some time reading & watching videos. The CV carb is not really all that complicated to rebuild or tune...

https://cv-performance.com/instructions-guides

Could also be time to check the tank for debris, the screen filter at the petcock, the fuel lines for delaminating, and if you have one of those vacuum petcocks, it could be leaky/acting up. Again, I've forgotten what years had those pesky vacuum petcocks were on...

Sorry I can't be more help....

You may want to post this issue in the EVO section... there are some pretty sharp EVO guys over there...

Good luck and post back when you find the fix....