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Engine Mechanical TopicsDiscussion for motor builds, cams, head work, stripped bolts and other engine related issues. The good and the bad. If it goes round and around or up and down, post it here.
I bought a 2017 dyna lowrider with 6500 miles on it. The bike has a high flow kn air filter (now new) and Vance and Hines big shots (new as well). Also running Vance and Hines tuner (again brand new and new tune installed) After I bought bike I discovered no baffle in rear cylinder ground pounder pipe and the tuner the bike had was not assigned to the bike so could not download a map. So I don’t know if the bike was ever tuned.
anyways the bike pulls really strong and runs perfectly down the interstate at most rpm. However, when I run around town at 2200 to 2500 rpm or so at like 45 mph or below the bike has a minor stutter or miss. Just enough to be annoying.
wondering if this is a normal characteristic or a concern. Hope someone can answer.
Going to get this out of the way first; there is no substitute for a dyno tune.
The "new tune installed" sounds like it need some fine tuning. If the V&H tuner is the FP3/4 Google "auto tune" and give it a try. Some have had some success that way.
I did auto tune today. Bike runs a little better. Just seems like this bike likes more than less throttle. I’m disabling my ACR with the FP3 then doing a compression test. Looking for a min of 175 psi and no more that 10% between cylinders. If, hopefully, that works out I’m gonna call VH support and try to get an across the board richer map. Not many or any tuners near me in Bloomsburg, PA so for now I’m doin my best and hoping for some support from forum. Thanks for the advice as I may have to come back to the well, lol
I did 3, 30 minute sessions prior to flashing ecm with FP3. They say at least 3 of 20 minute duration. The 175 is from shop manual. 175 minimum with ACR off. Hope it’s more than that but I’m trying to rule out anything big like a burnt exhaust valve etc.
I did 3, 30 minute sessions prior to flashing ecm with FP3. They say at least 3 of 20 minute duration. The 175 is from shop manual. 175 minimum with ACR off. Hope its more than that but Im trying to rule out anything big like a burnt exhaust valve etc.
Did you apply the changes after every session or just at the end? Most tuners have narrow limits as to how much change they can make at once, that's why it's important to keep applying the changes as your map may be off more than can be changed in one update
While in Auto Tune you should stay in the problem area as much as you can to gather data
A data log would go a long way to see what's happening while you're experiencing the problem, that's my biggest issue with the Fuel Pack platform
yes, i hit apply each time then finalize at end. Bike was flashed 3 times. I kept the app going and I could see a spot that I was in alot of the time. It was the are where I perceive a little skip. Funny though, as I was riding I noticed just the bumps in the road at those speeds married to the sound of the engine almost feels like a skip. I came off a 2019 road glide special, throttle by wire and alot heavier. Maybe I'm sensitive to change. That is one reason I want to do this compression check to make sure engine is healthy. Do you happen to know what a stock 103 compression range should be? I only know shop manual minimum.
That is one reason I want to do this compression check to make sure engine is healthy. Do you happen to know what a stock 103 compression range should be? I only know shop manual minimum.
Thanks, warm up, ACR off, air cleaner off, plugs out, install tool, WOT, turn her over until needle stops climbing. Looking for 175 to approx 190 each cylinder. Crossing my fingers
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Slight engine miss
