I have been wanting to go to a after market stage 3, 117 or 120 however I've been holding off because of the sumping issue that others have been having.

Are all the M8 engines involved with sumping issues or is it limited to the CVO stage 3 & 4?

I really need to know before making the investment.

Thanks in advance

 

I have a 120 m8 with no problems

 

Nearly 13,000 miles on my stage III, runs great, no issues.

 

Why wound you not want to go with the better oil pump? The improved oil pump is the fix.

And quit calling anything to do with a bike an investment.

 

I have had two M8s in the past 10 months no issues at all.

 

Which 120" kit did you go with?

 

It effects ALL M8s that installed had the stage III AND stage IV kits installed prior to HD releasing the new kits after mid July when the service bulletin came out. All new stage III and stage IV kits come with the new oil pumps. There are completely new pumps designed for boil air/oil cooled and water cooled engines.

Do a little bit of research and you will find multiple good threads covering this extensively as well as the service bulletin from Harley that will explain the fix to you.

I speak from experience, my 17 Ultra Limited is on its 4th engine. I had gone through 1 stage III and am on my second Stage IV now. I currently have the latest oil pump and 500+ miles on the engine and no sumping yet.

I have not heard about any of the aftermarket bikes that having the big bore kits, such as the one from FM having any sumping issues. I have mix feelings about this.

If the stock original oil pump can handle a big bore kit from an aftermarket provider, what does that say about Harley's? Are the Harley kits inferior and have an inherent design flaw that was easier and cheaper to design a new oil pump to handle the problem with the engine?

I know that the aftermarket big bore kits are using the original oil pumps and not putting in the new/improved ones, at least not that anyone has stated yet and they are not reporting issues.

Hope that answers some of your questions.

 

Yes there are multiple threads covering this, but there are more questions than answers.

what does the new oil pump actually do differently?

Stage II does not require a different pump, the difference between a II & III is bore size, some valve springs, lifters and a little more cam. why do those differences require a different oil pump? So is it a bore issue or a valve train issue?

I thought the sumping was caused by leaking piston coolers. if there not leaking and there is no sumping should we opt for the new oil pump anyway? whats the advantage?

My stage III has not had any issues in 13K miles. You folks with multiple engine failures from sumping, Why are they sumping?

 

HDrider17 thank you! That's exactly what I wanted to know.

Sixguns thank you as well, that's the issue that is keeping me from diving into a stage three kit. I just can't wrap my head around what would be causing this issue.

 

For the record, I had the latest Stage 4 kit installed on my '17 CVO Limited AFTER they were released in July. I had the latest oil pump from SB1450 and the bike still sumped... badly. Engine was toast after less than 500 miles. 3rd engine was installed yesterday. Supervised by MoCo dealer rep. Test ridden 50 miles by dealer rep. Its being detailed for my pickup today. I was told it has the "newest" latest oil pump. Go figure!