Primary vent causing a different transfer problem?
Club Member
Joined: Feb 2013
Posts: 9,767
Likes: 8,637
From: Edmonton, Alberta
I have had zero issues with my 18 m8 deluxe. But what I am noticing is that I do not rev the engine up and shift at high rpms. I was also notified by the shop foreman about the need for the m8 to be warmed up prior to operation. and every one is so afraid to let the v twin idle. More warm up time and less high rpm shifting. shifting at 6500 rpm. I have been monitoring the failures that people describe. Seems the high rpm crankcase pressures are the issue. I will be curious to see the affects down the road upon modifications from people.
Seasoned HDF Member
Joined: May 2008
Posts: 21,026
Likes: 12,549
From: South Carolina
Have you seen a single post about the vent causing another problem on any forum?
But of course the guy selling clutch pushrods is ranting about this problem on facebook...
Get it?
But of course the guy selling clutch pushrods is ranting about this problem on facebook...
Get it?
Last edited by Dan89FLSTC; Jan 1, 2020 at 01:04 PM.
Road Captain
Joined: Jan 2008
Posts: 715
Likes: 81
From: London, UK
I have challenged him on this and other things he promotes on facebook several times, (he always loses the debate) and even once earlier today on StreetGlide nation, he lost the argument so bad he turned off commenting.
Road Warrior
Joined: Apr 2015
Posts: 1,535
Likes: 780
From: Manitoba
O dam now I have something else to worry my bike is going to do. But hey I just remembered I've never had much if any transfer and have none of the fix's done on my Aug of 16 built Road King. I guess I'm one of the lucky few.
Member
Joined: Jul 2009
Posts: 4,310
Likes: 1,079
I don’t think the LACK of primary issues on this forum is a strong enough sample. Just like any particular 2020 bike WITH the primary vent installed from the Factory is not conclusive either, since HD could have discontinued the vent shortly after that particular bike was built.
What is interesting is that the vent kit part # 26500027 is still available on the Surdyke website but it has been removed from the Harley Davidson website. IMO, I think the primary vent kit still needs some confirmation from HD before further installation given the kit’s removal from their website.
What is interesting is that the vent kit part # 26500027 is still available on the Surdyke website but it has been removed from the Harley Davidson website. IMO, I think the primary vent kit still needs some confirmation from HD before further installation given the kit’s removal from their website.
Seasoned HDF Member
Joined: Aug 2006
Posts: 24,418
Likes: 30,640
From: Pennsylvania
So I install one of this guys fat rods in my brand new motorcycle that is under warranty, which is an unauthorized part, and also install his crankcase vent kit, which might not be approved by the EPA. And if I ever have the need to use my warranty for my clutch, transmission or engine..........what could go wrong???? Nah - no thanks.
Stellar HDF Member
Joined: Jan 2013
Posts: 2,747
Likes: 419
From: Vermont
Just another BS story.....like was said. He is sitting on a pile of expensive parts there is no need for now that guys know the simple mods that are free( stuff most of use have done since the shovel/EVO days) Now have 5 m8s i work on and simple modifications did away with forums concerns most have. Funny i have one guy that doesnt own a puter....he has 59k on a 17 limited untouched from the factory other than me venting heads to atmosphere and i copyed stone colds milled clutch cover during and aim install. He gets on it and i dont see it for 4-5 k. No tranfers or stumping or anything really. Uses no oil at all in all 3 holes . He wants all 3 holes dumped and replaced everytime with factory trans/ primary oil and uses dino in motor. Sometimes K.I.S.S. is best. Lmao.
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Stellar HDF Member
Joined: Jan 2013
Posts: 2,747
Likes: 419
From: Vermont
he's an unscrupulous FOS d-bag...I called him out on this comment of his FB post awhile back asking him to provide evidence of his report, and also posted this same thing here..then I went back to his post and reported my wife's 12 / 2019 build just arrived with the primary vent..he has a personal agenda to discredit the MOCO in order to help advance his sales
Road Master
Joined: Aug 2012
Posts: 1,008
Likes: 229
From: Saskatchewan
Let me wrap this around my brain... Apparently the transfer of oil from the transmission to the primary is cause by a negative pressure, a vacuum build up, in the primary sucking the transmission oil into the primary. The vent releases this vacuum stopping the transfer. Now this individual claims releasing this vacuum in the primary is causing a higher pressure in the crank case to move oil to the primary? If there is an issue with engine to primary transfer wouldn't a non-vented primary make a high crankcase pressure transfer more engine oil in a primary with a negative pressure builded up?
