QUOTE=squibb34;6478914]Easy enough to check for the breather valve, on the back of the primary case.
All 2021 bikes should have the 8 lobe scavenge pump fitted at the factory, but it's down to the date of manufacture I guess.
This vid from Doc Harley explains the issue: -
Easy enough to check for the breather valve, on the back of the primary case.
All 2021 bikes should have the 8 lobe scavenge pump fitted at the factory, but it's down to the date of manufacture I guess.
This vid from Doc Harley explains the issue: -
.........
https://www.youtube.com/watch?v=I4RJIZGr558
Thanks Squibb34 ... after being a little concerned initially and trawling thru LOADS go YouTube videos, I contacted the local HD dealer who told me as mine is a mid 2021 M8 107 the problem with the oil pump was fixed long before mine was built, ... I'm assuming that all of the other "related?" problems requiring very expensive after market solutions are just made up ? ..
It seems like there are a lot of people getting very worried and looking for snake oil solutions, ... I think that all major car and motorcycle manufacturers must have "crankcase pressure" issues to resolve and engineer in solutions that don't require hours of YouTubing to find a cure. ... such as a $400 oil cap/dipstick with a hose and a filter. I thought this comment below was the most reasonable thing I read, . ... but I admit I am no engineer and don't really understand it all.
"Batglide
7 months ago
Well it's an imaginary problem. Believe it or not the motorcycle has breathers that vent excess pressure already on the motorcycle. The 'issue' is that the EPA does not let Harley, or any other manufacturer, vent to atmosphere. That means the breathers vent into the intake. This ensures that all gasses are going to end up going through exhaust. What people dislike is the fact that when these breathers are working there is the possibility of atomized oil entering the intake. If all of this oil is not sucked in by the intake you get what is called blow by and oil actually escapes the intake and gets stuck in the air filter or flies out of the air filter and onto the bike. All of these 'fixes' are unnecessary and to my knowledge there are no data driven analysis that support the need for something like this. If blow by is such a huge problem a really easy fix is to ensure that your oil is not filled to maximum capacity or higher."
Kj Knuth
6 months ago
@Batglide blow by is from bad rings. Oil from the crank case being pushed into the cylinder.
The M8 and TC can push too much oil through the breathers and it introduces more than just air into the cylinder. Most guys will never notice it but anyone that actually runs their bike hard will end up with excess carbon build up on the piston and valves. This ends up being a problem way down the road assuming normal conditions. HD allows problems to happen so they can sell the solution via screamin eagle.
Can you fix it cheaper? Yes but the part of that question thats more important than cost is the fix. $10 spent vs $400 is great until the motor locks up from oil starvation."
Batglide
6 months ago
@Kj Knuth the blow by pushes excess vapors and oil into the intake through the breather bolts. That's the exact purpose of the breather bolts. When people complain about blow by on their Harleys they are complaining about the oil exiting the air filter and hitting their bike or pants, or they are complaining about excess carbon buildup. Firstly, oil vapor in the air fuel mixture does not contribute meaningfully to carbon buildup. Engines vented to atmosphere still get the same amount of carbon buildup. Secondly, excess crank case pressure is already being vented out of the breather bolts. That is their purpose. Every motor company uses some form of breather bolt setup to relive excess crank case pressure, cars usually use PCV. To solve the issue of excess oil entering the intake and possibly not entering the combustion chamber as designed would be to integrate a catch can of some type between the breather bolt and the intake. If you can show me quantitative data that proves that the breather bolts are not venting enough crank case pressure and that this aftermarket product does, I'll eat my words. But I've looked it up and I can't find any evidence if either."
Kj Knuth
6 months ago
@Batglide then don't buy the product it's basic economics. There's a reason that companies have went this route and a reason motors are blowing up from the factory. I don't know either and I suspect neither do you but I can about guarantee it's the same reason"
Batglide
6 months ago
@Kj Knuth ... uhm motors aren't blowing up from the factory. Even when they had sumping issues, that only affected a small minority of all M8s being produced at the time and that problem has been fixed for years now. You obviously have no clue what you're talking about, but if you want to spend hundreds of dollars on a modification that won't increase performance, reliability or even look cool then that's up to you little buddy. ������"
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https://www.youtube.com/watch?v=I4RJIZGr558[/QUOTE]
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