Sumping and M8 motors

big fella

big fella

Well-known member
UKGSer Subscriber
Joined
Jul 3, 2003
Messages
746
Reaction score
22
Location
On the home straight
After a brief interlude with a 1250 gs adventure, too many modes, too much plastic, I'm now thinking of buying another Harley. I test rode a 2021 street glide which I thought was great and also have an option on a 2021 demo Road glide. I have also the opportunity to buy a 2019 RKS with 600mls. As a result i thought id familiarize myself with any issues and see that sumping may be a problem. The RKS is a private sale and no warranty regarding repairs and would be my bike of choice. How big of an issue is sumping and should it be done on a recall or could an independant mechanic sort it. The other serious issue seems to be oil pumps. Is this typical internet forum gossip or are oil pumps giving trouble. When you start looking at Vtwin forums the yanks have a tendancy to drift off topic so a clear answer is nigh on impossible.
Bf
 
Oil pump was updated for 2020 model year - it’s retro fit so buy newer then 2020 or budget to upgrade.

As I understand it - it only happens after very long hot runs….. like an all day ride etc

The fuss about seems to have died down a bit / maybe cos riders are not doing the miles
 
….

Competent Home mech or Indie could do it
 
I understand the gearbox to be the problem on these models, knowing someone who has had two eat the gearbox after it has leaked all it`s oil into the engine.

HD though, so crude American engineering for crude people.
 
Never had an issue, some do, some don’t, but sustained high speed seems to be the biggest common denominator.

Mines a 2019 model so version 2 of the oil pump I believe, now on version 3.

2020 models are still reporting some sumping issues, so it’s not just the oil pump, hence breathers seem to be the next big thing to mess around with.
 
att said:
I understand the gearbox to be the problem on these models, knowing someone who has had two eat the gearbox after it has leaked all it`s oil into the engine.

HD though, so crude American engineering for crude people.
Click to expand...

Thicker pushrod and or primary vent seems to sort that. My 2019 came with the primary vent and again, no issues at all.

My brothers 2017 107 did have an issue but the primary vent has sorted it.
 
Have had two 114 M8s (a Fatboy and a RKS) in the last 3 years and did about 15k miles between then both.

Zero issues with either bike I owned although some have had minor issues with the M8 that should have been sorted by now so nothing to worry about if you're looking to buy an M8 engine bike. :thumb2
 
American bloggers seem to suggest its a breather issue, or rather lack of a breather on gearbox.
 
luckylucian said:
American bloggers seem to suggest its a breather issue, or rather lack of a breather on gearbox.
Click to expand...

That’s more for the gearbox to primary oil migration.

HD did indeed add a breather tube to the primary to try to resolve it. That is not sumping though.

Engine breathing is usually done through the engine oil filler cap or plate on the rear of the engine (trask I think make the plate), although some engines seem to have had issues with the squirters that jet oil to the underside of the pistons. If these fail they over oil the engine and the oil pump can’t cope causing excess oil in the crank chamber, this is what is meant by sumping.
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
You must log in or register to reply here.

Similar threads

Canada: Quebec Winter Carnival and the Rockies
Replies
0
Views
1,580
John Roberts
An excellent (and eventful) solo trip to the Scottish Higlands this April
Replies
16
Views
4,410
kurienp
kurienp
A ramble around Romania and the Balkans
2
Replies
23
Views
11,295
Drumacoon Lad.
Emoto
Accessorizing the R1200GSW: AltRider Skid Plate and Crash Bars
Replies
1
Views
3,813
NickD
Giles
Big bike trails, Pyrenees
2 3
Replies
48
Views
21,933
Beamer
Beamer


Back
Top Bottom