I have had a couple of motorcycles with various upgrades (stage 1, cams, etc.). I typically pay for dyno time and have read tons of comments about the importance of skill and technical merit of the person doing the tune.

For the uninitiated, what are 3-5 signs that your bike is really well tuned? What would be some indicators of the bike being poorly tuned? I have the dyno sheets for some bikes and have looked for increases in power/performance. What are other factors to consider?

Let's hear some ideas: how can you tell if you got a good or great tune? how can you tell if the bike needs a retune or if you got a dud?

 

How the bike runs, decell popping, starting, acceleration, does is hesitate? gas mileage way down. pinging, all factors in a properly tuned bike

 

Proper tuning is a compromise across several thresholds.
As Charlie said above, several "symptoms" present themselves which will indicate a proper tune. You typically can not have a high horsepower tune, without suffering in some other way. You can have one running very lean, proper atomization and complete burning of fuel, and get max horsepower. But that max horsepower comes at the expense of building additional heat. Richen it up, and you will cool it off. But risk unburned fuel, fouling plugs, blubbering in low RPM Ranges, not a "clean running" bike. Increase spark advance to burn more fuel, and you risk hard starting, pre-detination (pinging), etc.
Just like with cars, there is no replacement for displacement. A larger engine will make more horsepower with less work than a smaller one. Lots of guys with 96" engines will push those bikes to their fullest extent, and make some very impressive horsepower. But are they running the pi** out of them to do it?

A good tune will have the enging running at its greatest potential without any pinging, while controlling heat (to the extent it can be controlled on an air cooled motor), have good power throughout the RPM range.

In sprint cars (world of outlaws), we didn't build those cars to run at 2000 RPMs, because they didn't race at that RPM level... We built them to run at 5-9000 RPM. And they ran like sh*t at lower RPM ranges. Typically going to take a green flag, the driver will have to "clean it out" just before taking the green flag.

Our bikes are tuned to a compromise of low-mid-high RPM Ranges.. That's where a good tuner will put in the time required to get it done.

 

Read this before your next tune.

From https://www.hdforums.com/forum/elect...our-tuner.html

5 Questions to ask your tuner Gentleman here are five questions you can ask your tuner to see what his skill level is without being conspicuous. These are 5 simple questions that a good experienced tuner can and will be able to spit out the answers correctly and without a great deal of thought and the whole time your asking themthe questions it will seem like a general conversation of you getting a little knowledge of the tuningprocedures from him.If your tuner can't answer all, or any, of these questions it's time for you to search out another shop.

1) How long will my bike be on the Dyno to tune the SERT?
(answer) 4 to 5 hours

2)How many Dyno runs will you have to make to finish a tune?
(answer) 50 to 70 on a average

3) What are people talking about when they say you have to SYNCHRONIZE the VE tables?
(answer) By Synchronizing the VE Table to the Fuel Table your telling the ECM the new air flow through the motor fromthe mods you made.

4) I heard something about a Step Test, can you tell me what that is?
(answer) The Step Test is a program in the winPEP 7 software (Dyno Software) that allows us to sample the AFR longer for a better reading at 2%, 5%, 7%, 10%, and 15% Throttle Position. This is where the bike lives so we want a good AFR sample to make our edits.

5) Do you change the AFR Table to one value as you tune?
(answer) Yes, 13.2. This makes it easier to synchronize the VE Table.


6) When was the last time the o2 sensor was calibrated or checked for the correct reading?
(answer) check for accuracy every 5 to 6 tunes.....replace the sensor after 20 to 25 tunes

If your tuner can answer these simple questions chances are (99%) you will get a good tune. I hope this will give you all a better idea who your trusting your $20,000.00 investment with.

 

I saw the word "pinging". Sometimes my bike sounds likes it has solid lifters...clattering and making too much upper end noise. I use premium gas too. At lights, I think people are wondering if it's falling apart because of the ticking noise. It's embarrassing. It makes me want to get loud pipes, to cover it up.

 

that sounds like a different problem, chicken. without actually hearing the noise, I would say you may be having a lifter problem, a well documented issue with harley. there are other factors there as well, but it sounds like you may need to have someone look at it or at least listen to it to see if it need attention. My bike has some noise at cold start and I have a high volume oil pump and jims lifters in it, but the noise goes away after a couple minutes, I'm not worried about it. I may do some changes this coming winter where I will address that issue, but if you are not sure, get a trained ear to lend a listen

 

to answer "pinging", thats something that happens on load, hard acceleration, uphill climbs heavy load conditions, where pre ignition starts due to various reasons, (poor gas bad timing, carbon deposits, ect) that starts a second flame front and that front runs into the spark induced front, and the collide violently, and cause a "pinging " noise. this is very bad as it quickly finds the weakest link, which in most cases is the top of the piston, and makes a "clearance" hole for the spark to exit from that point on, as most know, holes in pistons are a non desirable condition!!!

 

Thanks for the reply Charlie!

When I got my bike, I was told...because it's so quiet, muffler wise, I'd hear more upper end noise. So I've sort of lived with it. And it's been at the shop for a few things but you'd think that if something wasn't right, they'd fix it. Plus it'd be a reason for them to beef up the bill! Not that they'd do that.

My ear is far from trained. But I know when my Panhead had solids, it was loud like mine is now.

 

When your ride runs like this, you pretty much got it dialed as good as it will get!!!

 

I heard a little bit of decel popping in the exhaust and seemed to have a slight lean overheat condition!!!!