full dyno tune on new build question

[hrdtail78]

Sure, that is a concern. But I look at it slightly different for somebody that's doing an engine overhaul in their garage. The bike ran before with what ever jetting (or FI map) that was in it. So why after a rebuild would the same fueling not work? From what I recall, this motor is not radically different from what it was before the rebuild.

-JW

Being a carb.  It is also dependent on this airflow change and can adapt to it better than EFI.

[Don D]

My attitude about EFI is exactly in line with what others have said. Get it to a tuner right away. This was a running bike that has had the usual and customary tweaks to the carb and does have an adjustable ignition.

[hbkeith]

I have only out of 22 Carbed Harleys ive owned , had 1 on a Dyno , not saying a Dyno is bad but for a Carbed bike i do not see it as a MUST , read the plugs and feel how it runs

[Hossamania]

My 95" went on a Dyno for break in and monitoring, then final tune on the carb. Maybe not necessary, but it took all the stress off of me for any potential early damage. I have been pounding this motor for over 100,000 miles.

[JSD]

Fit a 200 main Adam 

[Scotty]

Fit a 200 main Adam

Why?  200 main only good for WFO and to rich anyway.
Use an AFR meter and you will see why.

[JSD]

190 stock 200 works on my 95 builds

[Scotty]

190 stock 200 works on my 95 builds

So basically you are just guessing as a 190 is rich enough for a 95" if you use a AFR meter and measure.
Does depend on the build though but his is not over the top.

[JSD]

Scotty What Size motor are you running the stock EPA 190 main jet on? Adam lives in a hot climate and wont be doing WOT runs till Motor is run in so WTF if it a tad fat, better than Lean AFR & hot running. Even a 80 cu Evo with mild build can use a 190. My tunes are checked by plugs cut open. Been in bike racing Since late 70s. Harley builds Shovel pan flatheads Evo TC any thing with a carby its not rocket science just cause harley put in a jet to suit EPA don't mean ya got to leave it there. Later bikes are on the AFR limit to pass EPA standards Then you add Air cleaner Pipes Ratio gets leaner Then fit higher flowing heads a cam and big bore kit The AFR ratio is even more leaner. You got your ways Ill stick to mine. The only Thing is maybe? You are using those made in China Knock off jets as i have tuned a S&S Knock Off Carb and those Jets where way off The 78 main measured  a tad over .072.  Also is your enricher seated ? Hope this Helps 

[JW113]

Before I had one, I thought I'd never say this. But now that I do, the AFR gauge doesn't lie. Yes, I tuned by the seat of the pants for decades. Then Turboprop convinced me that hillbilly tuning is just that. I was quite amazed after getting an AFR gauge how over-jetted my "seemingly perfectly tuned-by-seat-of-pants" motorcycle was. And even more amazed after I let the AFR steer me to getting the air/fuel ratio via jetting to the correct setting. I went down quite a bit on jet sizes, at least on the main. The pilot (we're talking Keihin CV) was 48, now 45. Main was 185, now 170. And using just the right number of washers under the needle. One more or less makes a measurable difference on the gauge. Throwing fuel out the pipe does two things: uses more fuel, and looses power. This whole nonsense about "gotta run it rich" is just that. Nonsense. Running WAY too lean is bad, but running the right jetting ends up being a lot smaller jets than you think they are, if you have no AFR gauge.

But... do as you will. What do I know?

-JW

[Scotty]

Scotty What Size motor are you running the stock EPA 190 main jet on? Adam lives in a hot climate and wont be doing WOT runs till Motor is run in so WTF if it a tad fat, better than Lean AFR & hot running. Even a 80 cu Evo with mild build can use a 190. My tunes are checked by plugs cut open. Been in bike racing Since late 70s. Harley builds Shovel pan flatheads Evo TC any thing with a carby its not rocket science just cause harley put in a jet to suit EPA don't mean ya got to leave it there. Later bikes are on the AFR limit to pass EPA standards Then you add Air cleaner Pipes Ratio gets leaner Then fit higher flowing heads a cam and big bore kit The AFR ratio is even more leaner. You got your ways Ill stick to mine. The only Thing is maybe? You are using those made in China Knock off jets as i have tuned a S&S Knock Off Carb and those Jets where way off The 78 main measured  a tad over .072.  Also is your enricher seated ? Hope this Helps

Good for you but I would not follow your advice.
As for what I use none of it comes from China but you keep grasping at straws and cutting plugs I live in 2022 not in 1970 and know what I am doing and I use a AFR meter and nothing here runs hot but it does run well.

[Hossamania]

I run a 95" with heads, Andrews 55 gear drive cam, SE flattop pistons, DTT ignition, CV44 carb. I'm running a 46 pilot, "L" needle, and, kind of embarrassed to say, a 250 main jet.
I've tried every combination of needle, jets, it was Dyno tuned a second time years ago and it ended with the 250. The tuner said that if he had a 260 he would have tried it. We were both surprised at the big jet. I changed things after thinking I knew better and still ended with the 250 as it pulls the best at top end. And yes, I spend a lot of time there. My build parameters when talking with the shop were, it needs to pull ahead at the end of the 1/4 mile, "I can't beat everybody, but I must beat my friends." It still does.
I consistently get 37.5 mpg.
Not exactly sure if this relates to the original post, but just pointing out that motors want what they want.

[HogMike]

2000 twin cam, stock heads, 95", Mikuni carb, DTT ignition. Andrews 26.

Just a mild build but it is so much fun to ride.
39-45 mpg, plugs look fine. No surges, hiccups, sneezes, pops or anything else while starting or running.

Never had it on a dyno, never saw a need. Have about 40k on this motor. And it does everything I want. Am I leaving some power potential there? Maybe, but I don't care, it works for me.

On my m8 with the big motor, definitely break in on the dyno and follow up after 1000 miles. I can't change jets, it's all EFI now.

Difference in black and white with carb vs EFI.

Both bikes are VERY well mannered and fun to ride but each one has its place.
New one is my high speed, long range touring bike and the 2000 is my solo day rider/cruiser.

JMHO
 

[Don D]

First it is not fair to compare jetting requirements of different builds and expect the exact same jetting for even a similar build. An AFR monitor is a good choice to get the jetting dialed in assuming the operator understands that steady state conditions are all that will be really accurate. The accelerator pump changes things and wile accelerating the mixture will go momentarily rich.

Next the factory CV40 mains are notoriously rich as a combination of the needle and the pilot on the low speed circuit were too lean for emission compliance. At the time the testing that was done for motorcycles was looking for total emmission load not what was being emitted in any particular driving sequence. HD could comply by the lean and rich carb as they did and not burn up engines (warranty).

[hrdtail78]

I have a 128 evo fitted with a 48, and high velocity billet heads w/ raised ports.  My jets are smaller than anyone would recommend?  Why, because a carb is a venturi and the faster the air moves, the less of a pressure is created, and more fuel will pull out of the bowl.  Different cams and exhaust will also affect this.  Same can be said on lazy heads and poor design exhaust combos going the other way.  There are decent starting points and then there is what the bike wants.

[Don D]

Yep and if some heard what I ran on my CV40 on a shovelhead they would flame me, same reason.