M8 problems

Reply Subscribe

Thread Tools

Search this Thread

Sep 22, 2017 | 09:53 AM

#901

Heatwave

Member

Joined: Jul 2009

Posts: 4,310

Likes: 1,079

Quote:

Originally Posted by frankegd

Not sure I need that kind of fame though...
But THANKS anyway.
So, with all that talk and no pictures: I went to the shop, looked at the bike and here we go - PICTURES!!
Not much to see, except some deposits on the front piston. Some discoloration on front cylinder, but no visible surface damage (I might be blind though...).
No other parts as far as I could see have discoloration or damage. Tech said he talked to MoCo and after a few min they agreed to send new engine.

I hope that helps.
Thank you.
FrankEGD

Yep, pretty much the same as mine. No wall scoring or piston damage but when they rotated the crank assembly there was significant increased resistance. Clearing the bearings had been damaged from the excess heat. Once they find excessive resistance in the crank assembly they simply authorize a replacement engine. Probably less costly than rebuilding the existing engine.

Sep 22, 2017 | 11:12 AM

#902

Max Headflow

Seasoned HDF Member

Joined: Dec 2005

Posts: 19,925

Likes: 8,027

From: poway

Quote:

Originally Posted by Heatwave

Not sure I believe that he bearings were damaged by excessive heat.. They should last as long as the temps stay below 200 C. The only way could be that the oil was breaking down or simply too much oil flooding the bearing since the crank is literally swimming in oil.. When sumping, the oil aerates. Maybe air in the oil pushed the pump causes the oil to oxidize and kills the lubrication properties. I would think at that point lifter would start to rattle.

What did the motor oil look like? If not to dark, I'd suspect too much oil flooding the rollers.

Sep 22, 2017 | 11:48 AM

#903

frankegd

Cruiser

Joined: Oct 2013

Posts: 237

Likes: 6

From: Jones

Quote:

Originally Posted by Max Headflow

My LCD thermometer on the dipstick showed 312 F while doing about 55mph on the interstate. I also have some oil I am going to have analyzed. It has been in the engine for about 10 days/ 200mls. We shall see what that says.
And BTW, it was dark, in like DARK!

FrankEGD

Sep 22, 2017 | 12:37 PM

#904

Heatwave

Member

Joined: Jul 2009

Posts: 4,310

Likes: 1,079

Quote:

Originally Posted by Max Headflow

All of those are possibilities. Without a forensic analysis of the engine its hard to say how the specific failure occurs, but if you smelled the oil from one of these sumping engines its rather amazing. Many Hundreds of degrees to get syn to burn like that. My lifters were completely blackened from the sumping failure and it was estimated I had only "miles" to go before seizure. Crazy thing is that until the moment of smelling the burning oil the performance on my second engine was actually OK. Once they removed the Crank Position sensor I had over 40 ounces of "boiling", smoking syn discharging into 2 pans (3oz is considered normal). I have a video of the discharge which is rather remarkable. The smell filled the entire dealership including the parking lot.

Last edited by Heatwave; Sep 22, 2017 at 12:40 PM.

Sep 22, 2017 | 01:01 PM

#905

Max Headflow

Seasoned HDF Member

Joined: Dec 2005

Posts: 19,925

Likes: 8,027

From: poway

So it sounds like the oil died which probably killed the bearings.. I find it interesting that you didn't notice the loss in power when the motor started to sump.. I would guess that ridding at a constant speed might mask the issue tho.. I've got a big motor TC that had a sumping issue but would notice when the issue occurred, it felt like the rear brake was on or simply going up a steep hill. Motr needed way more throttle to pull and way less to slow down. In my case, letting the motor simply idle would correct the issue.

312 F is only about 156C. Probably more than enough to kill the syn3 or any dino quickly.

Sep 22, 2017 | 04:06 PM

#906

Heatwave

Member

Joined: Jul 2009

Posts: 4,310

Likes: 1,079

Quote:

Originally Posted by Max Headflow

It definitely had sumping power loss earlier but not at the time it began to fail which was strange. First engine definitely had significant power loss due to sumping. At first no body would believe me whan i said 50% power loss. But once they issued sb1450 they finally started listening.

Sep 22, 2017 | 04:29 PM

#907

Keithhu

Seasoned HDF Member

Joined: Sep 2009

Posts: 17,148

Likes: 6,171

From: SE Michigan

Quote:

Originally Posted by Heatwave

Same here, they scoped it, no wall scoring, but burnt up oil, 1 qt down after less than 1K miles past 5K service, lifter rattle etc. Moco told the dealer not to tear it down, they are sending a replacement engine and they want the whole engine back in tact.

Sep 22, 2017 | 05:02 PM

#908

Max Headflow

Seasoned HDF Member

Joined: Dec 2005

Posts: 19,925

Likes: 8,027

From: poway

Quote:

Originally Posted by Heatwave

I would think that the damage is done after the oil is toasted.

Generally when a motor starts sumping seriously something is wrong and it shows up. Early TCs had the random sump issue and HD came out bulletin on how to install/tighten the cam plate and oil pump..

One thing that is interesting is that the cam-plate install procedures for the TC and M8 are different..