What's up with this high idle bullish*t?
#11
04-14-2019, 05:38 AM
My bike does this as well but only jumps to about 1300 as I'm coming to a stop and settles back down once I'm fully stopped. It has always done it so I didn't think much of it. Seems to do it more now though. Can you possibly share how you went about finding the intake leak? Sorry if this is a dumb question, I still have a lot to learn on diagnosis of issues.
The following 2 users liked this post by modular:
Bowhunter8607 (04-15-2019),
todd-67 (04-20-2019)
#13
04-15-2019, 10:52 AM
Road Warrior
I'm always willing to help...not a dumb question at all. I'm not a guru mechanic...I learn as I go too. But, I'll try and help.
First...do you have a stock throttle body and manifold? If you do, one of the biggest complaints I seen/heard is the plastic manifold warps from engine heat...could crack or just not seat right. Harley now sells an aluminum stock size replacement manifold for M8's. Also, I read about a couple stock throttle bodies cracking, but not positive on how...probably over tightening. Some have used a soaping water solution or a non chlorinated cleaner to spray around the seals of the manifold and such to search for leaks...if you do this, use it "lightly".
In my case...I just got a flashlight and started looking at all the seals to make sure things were seated correctly. I found that my front breather bolt was not tight and left an 1/8" gap between backplate and TB. Then I noticed that the manifold did not look seated completely...and sure enough, I could wiggle the TB and manifold. Thats were I stopped...pissed that the shop didn't find this very basic leak.
The leak might be the issue...but might not. There is a known "background idle issue"...Dynojet does not know a fix, but Jamie does know how to fix it. True story. Very few bikes are affected...9 times out of 10 it's a different issue causing the erratic idle.
First...do you have a stock throttle body and manifold? If you do, one of the biggest complaints I seen/heard is the plastic manifold warps from engine heat...could crack or just not seat right. Harley now sells an aluminum stock size replacement manifold for M8's. Also, I read about a couple stock throttle bodies cracking, but not positive on how...probably over tightening. Some have used a soaping water solution or a non chlorinated cleaner to spray around the seals of the manifold and such to search for leaks...if you do this, use it "lightly".
In my case...I just got a flashlight and started looking at all the seals to make sure things were seated correctly. I found that my front breather bolt was not tight and left an 1/8" gap between backplate and TB. Then I noticed that the manifold did not look seated completely...and sure enough, I could wiggle the TB and manifold. Thats were I stopped...pissed that the shop didn't find this very basic leak.
The leak might be the issue...but might not. There is a known "background idle issue"...Dynojet does not know a fix, but Jamie does know how to fix it. True story. Very few bikes are affected...9 times out of 10 it's a different issue causing the erratic idle.
Thanks for that. I will get in contact with FM for any possible adjustments.
#14
04-15-2019, 10:58 AM
Seasoned HDF Member
My ‘17 RoadKing, did that...to a degree...after I did the HD Stage 1 download. Why I said “to a degree” it reved to about 1,400 RPMs, under those conditions. There were other threads on this. It seems the MoCo, made these modifications to prevent stalling.
so..I wonder if the 3rd party tuners start with an HD base map, that now has this characteristic?
so..I wonder if the 3rd party tuners start with an HD base map, that now has this characteristic?
#17
04-17-2019, 06:25 AM
#19
04-17-2019, 12:48 PM
#20
04-19-2019, 11:22 PM
Outstanding HDF Member