Running with enrichener on...

Discussion in 'Engine, Fuel and Exhaust' started by Cleftwynd, Jun 8, 2010.

  1. Cleftwynd

    Cleftwynd Banned

    On my 90 Evo I have always had to run with the enrichener on as I have changed both the intake and added SE slip ons MANY years ago. It needs full enrichener to start cold, then needs 1/4" to 1/2" out on the enrichener to run without popping once it warms up.

    I have never had any issues with it as it has always ran like a top like this, never fails to start, idles great, power is good. After reading a lot here about rejetting after stage 1 mods or changes to the engines breathing I now am wondering if I need to change the jets, or is it fine to keep running it this way.

    50,000 miles running with enrichener, so I can't see it has caused any harm (at least I hope not). Will it change anything other than not needing the enrichener when warm if I rejet?
  2. Jack Klarich

    Jack Klarich Expert Member

    If the carb is a C V stocker it is too lean from the factory, a bit more fuel wont hurt anything except your mileage JMO
    Last edited: Jun 8, 2010
  3. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

    You should be able to start the cold engine using the enricher, and then push in the enricher all the way while increasing the throttle by hand to around 1200 rpm. Use the throttle lock thumbwheel to hold the rpm there at 1200 while the engine warms up until the valve covers are warm to the touch before heading out.

    You are compensating for undersized jets by using the enricher. You should be able to run without it.

    Probably has not caused any harm. As indicated above, you are compensating for undersized jets (and possibly an intake air leak) using the enricher.

    I suggest getting the HD Factory Service Manual for the '90 FXSTS and go through the carb completely. Clean it well with mineral spirits followed by carb cleaner spray. Especially chase all the jetways. Ensure that the idle/air mixture screw is uncovered on the bottom of the carb. Take out the needle screw and chase the port liberally with carb spray. Reinstall the needle screw gently. Back it out 2 1/2 turns from seated as the starting setting. Replace the accelerator pump guts completely.

    Replace the jets starting with a #46 low, and 185 high. Buy also the #45 low and the 180 and 190 high. This will allow some further adjusting if necessary. You can reuse the stock needle unless it looks damaged. If replacing, use a stock needle. Whichever, put two #4 stainless washers under the needle.

    Reassemble the carb with all new orings, gaskets and seals. I would also suggest removing the intake manifold and replace the seal and gaskets there.

    Fire it up and see how that is. If necessary, replace the jets based on performance. But this a pretty good starting set up and may be just what the Doctor ordered!!

    CV Carburetor Jet Adjustment/Trouble Shooting - Harley Davidson Community

    CV Carb Rejet Pics - Harley Davidson Community (do NOT drill the slide!!)

    Float Level Test - Harley Davidson Community