First 10 minutes of Ride poppin and gutless, Fuel additive

I have a 94 Dyan Low Rider. I have owned it for 6 months, has 20k miles. The seller said it just had it's 20k mile service. It's chilly in the mornings about 50 degrees. I start it and let it warm up for 15 minutes or so, still the first 10 minutes of my ride the it cust out, backfires, hic-cups, etc. then it's fine! Shall I try a fuel additive to clean the carb before trying anything else? If so what do y'all recommend as an additive?

A couple things can cause your problem, first it may have a small intake leak, you can spray carb cleaner or ether or wd 40 or run a hose from your propane tanks and see if the idle changes when you spray around the intake connectins, but usually intake leaks make them run poorly all the time not just when it is cold, if that is good my guess is you are running stock carb settings, CV carbs have a plug on the side of them that is covered so you cant tamper with the idle air mixture to meet emmissions, you need to drill that plug off and adjust your idle air mixture screw to run richer at idle and it will help your cold bloodedness tremensously and also run cooler idling in traffic in the summertime, Im sure Ken or someone will be around shortly to tell you how many turns the screw should be out, but if your bike is stock I bet that is your problem, Todd

Before I traded, I had a bike with a CV that would do pretty much the same thing in cold weather and even could be slow to warm up in warm weather after I had done the stage 1. I found that I had three options: drop the clip on the needle one notch which made it do much better in cold weather (richer) which tore up the gas milage, tolerate the cough, spit and hic-coughs until spring & three pull out the choke (enrichening valve) just a bit when needed. I chose the third option plus opening up the idle mix screw about 3/4 of a turn in 1/8 turn increments and that kept me and the bike happy until warm weather. During warm weather, we both were happy. If you're the least bit lean and have a stage 1 air cleaner, the air has no chance for warming and goes through at a high velocity. Hope this helps.
Danny

Fuel additive won't fix the "carb farts" & Todd (duke76) is spot on - intake manifold leaks and/or carb not adjusted right will do it every time. Check for intake manifold leaks, remove the plug covering the idle mixture screw & set it @ 2.5 turns out to begin with. Shouldn't have to go more than 1/4 turn either way to hit the ideal sport between too rich & too lean. If you do, or adjusting the screw does basically nothing, the slow jet is the wrong one. Re-jet the carb as necessary for your application - probably 45 slow & 180 main but I don't know that as I'm used to Sportsters, but for comparison purposes, baseline for a '94 1200 is 42 slow, 175 main.

And I'd bet $$$ the needle needs changed - it sure does in Sportsters prior to '04 & the CV carbs are the same as on Dynas. The infamous N65C needle (part # 27094-88) you can pick up from a dealer for about $8, although you may want to look into the kit "kenfuzed" has available. Assuming no intake manifold leaks, the problem is in the transition phase off the idle circuit & usually around 2500 rpm is where you see the problem on dyno charts - the carb spikes way lean. People have been drowning that with a bigger slow jet for years, but it doesn't solve the problem - changing the needle does.

The "carb farts" are worse in cold weather since the air is more dense & that throws your air/fuel ratio off some, but a CV carb does a good job of compensating - I wouldn't say it adjusts itself, but in a way it does. As the slide raises & lowers, so does the needle & if it's not the right one for the application, fuel metering is off, especially during the transition phase & you can get the "carb farts" in July.

That was no doubt the DynoJet needle as the ones from the factory are not adjustable. The DynoJet kit is an attempt @ a "one size fits all" deal that you adjust for whatever bike you put it on, but it's nowhere near as good as getting the right needle for the particular application. And tests have shown that even when you do get a DynoJet setup dialed in, fuel mileage is noticeably lower.

Also, that kit uses different jets & emulsion tube. Stock parts will not interchange so you either have to play with the DynoJet kit or take it out & go back with stock parts. Which is what I did with one bike I bought used & had the DynoJet kit in it & what everybody else I know does. Stock parts are easy to work with & they don't cost very much - last time I was @ a dealer for jets & a needle I spent about $15.

Another thing is you can get the DynoJet kit with (or without) the "Thunderslide" - a lightweight plastic slide that causes more problems because it raises too fast & "hunts" going down the road, always trying to find the right spot which it never does. If you find that slide instead of a stock one, go back with stock & don't drill it out like DynoJet says to.

There are a lot of gimmicks on the market & H-D dealers often installed the DynoJet kit and/or changed jetting on a new bike. So when buying a used bike, one of the 1st things you want to do is pull the air-cleaner & float bowl to see what you've got - might assume the carb is stock, but odds are somebody's already messed with it.

some good advice has already been posted,but this is the most common problem ive seen come in the last few year.more so on later model bikes 86 and up.could be water in the float bowl. there's a drain screw on the bottom of the float bowl easily aaccesed from the left side between the cylinders.back it out to drain the moisture that collects in the bottom of the bowl.you do not have to remove it completely. uits a good thig to make this a monthly procedure when you are riding.dont panic, its not necessarily contaminated fuel, but can als be caused by condensation.closed system tanks are much worse aboutthis than older vented ones.doesnt cost a penny to try.

It's something to deal with- Like the man said the bike has to warm up for 8-10 miles @ 2500 or below before you start worrying to much.
I run a 93 FLHTC with stock CV and have had the same problem, which I'll be addressing this spring as soon as the cold weather leaves the area.
Plan on installing a Stage 1 w/ Arlen Ness Big sucker AC and remodified mufflers.
For an 80 cid. stock this is all I think that is needed; anything more and I'll have to open the cases up. Like the old saying goes: (If it ain't broke- Don't fix it!)

Cold engine and holding at one speed used to give my Sporty the carb farts. It stopped 99% after rejetting/Stage 1. Good luck