M8 problems
Seasoned HDF Member
Joined: Jan 2008
Posts: 13,674
Likes: 11,461
From: State of Confusion
If I would ever consider stage 3 I would upgrade to cam-plate and fueling or S&S pump but for stage 2 I dont feel throwing extra 500$ is needed. It is proven that 2020 pump is good unit and helps with issues of sumping which is main reason we upgrade it.
From what I researched one good advantage of fueling and ss units is that they create a lot of flow which in turn help with way better cooling in the process. Some said temp drops up to 20 degrees which I consider a lot due to more laminar flows due to high quality manufacturing tolerances comparing to stock castings which needless to say is more $$$ efficient for MoCo. This temp drop would be one and only reason I would even think to do this upgrade at stage 2 but is it worth it 500$ extra to have a bit cooler engine - not sure about that part.
If bike is tuned properly and use good oil (Amsoil for me lowered temps 10deg before) I think this motor will be really happy.
I am not an expert of any kind but this is what I found out while watching few videos on YT - mainly Baxter garage dude. He is smart and make a lot of sense.
From what I researched one good advantage of fueling and ss units is that they create a lot of flow which in turn help with way better cooling in the process. Some said temp drops up to 20 degrees which I consider a lot due to more laminar flows due to high quality manufacturing tolerances comparing to stock castings which needless to say is more $$$ efficient for MoCo. This temp drop would be one and only reason I would even think to do this upgrade at stage 2 but is it worth it 500$ extra to have a bit cooler engine - not sure about that part.
If bike is tuned properly and use good oil (Amsoil for me lowered temps 10deg before) I think this motor will be really happy.
I am not an expert of any kind but this is what I found out while watching few videos on YT - mainly Baxter garage dude. He is smart and make a lot of sense.
Grand HDF Member
Joined: Aug 2017
Posts: 3,586
Likes: 889
From: Nowhere
I dont care if you guys believe me or not. In the past I had hot rodded 1994 Sportster that at some point was really sensitive to temperature due to high compression ratio. I tried many oils and Amsoil was the only one that got the job done and made a difference which allow me to avoid detonation. You dont want to believe it I dont really care I know what I experienced.
Intermediate
Joined: Apr 2018
Posts: 29
Likes: 6
From: Ohio
I feel there is a lead mechanic at this shop who likes to push high performance parts...probably his personal preference, and that is appreciated, but I cannot really afford the high end stuff, nor do I have the need to blast down the strip or tear **** up.
Just want assurance I can own and ride a quality product, made in the USA, that won't crap out on me when I need it.
Intermediate
Joined: Apr 2018
Posts: 29
Likes: 6
From: Ohio
Good point. I haven't really ridden it far or hard. I'm retired now and plan on taking some long trips. I guess hearing all the bad stories about sumping have got to me, in that I can't be sure that it still might, or might not, happen...
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
Last edited by Jeff1759; Jan 29, 2021 at 09:45 AM.
Stellar HDF Member
Joined: Mar 2016
Posts: 2,285
Likes: 965
From: Eastern NC
Good point. I haven't really ridden it far or hard. I'm retired now and plan on taking some long trips. I guess hearing all the bad stories about sumping have got to me, in that I can't be sure that it still might, or might not, happen...
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
If you are really worried, push your bike hard with high rpm's on back roads or hills for several hours then hit the highway doing 70-80 mph.. It will be good for your confidence and a good time to blow the carbon out of that motor of yours.
Intermediate
Joined: Apr 2018
Posts: 29
Likes: 6
From: Ohio
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Seasoned HDF Member
Joined: Sep 2009
Posts: 17,148
Likes: 6,171
From: SE Michigan
When the M8 was released sumping was more common with riders that use their bikes in the higher RPM range, that's why stage3 and 4 were having issues originally. "Disclamer" I did say more common on S3 &4 but have read where some owners reported sumping on stock bikes. The cam HD S3&4 comes on in the mid to upper range so these guys ride the bikes harder than you. I had a 2017 SGS with stage 1 and rode it 21,000 miles without any concerns or symptoms of sumping. In a trip to the mountains two up, we rode a for 10 days 8 hours per day straight, keeping the RPM's above 3500 for hours of up and down steep inclines, then hitting the highway back to camp 70-80 mph.
Road Captain
Joined: Sep 2012
Posts: 609
Likes: 159
From: Allover
Good point. I haven't really ridden it far or hard. I'm retired now and plan on taking some long trips. I guess hearing all the bad stories about sumping have got to me, in that I can't be sure that it still might, or might not, happen...
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
I've got 10,500 miles on it. While there is logic in the fact that it hasn't happened yet, so there is no need to fix something that isn't broken, I can't stop the nagging thought that it could still happen.
Haven't been an avid follower of the sumping issue threads, but are there cases where's it has occurred after 10,000 miles?
