80 in. EVO compression

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Jun 17, 2024 | 05:25 PM

#21

WP50

Seasoned HDF Member

Joined: Apr 2011

Posts: 6,185

Likes: 2,134

From: W. Texas

Quote:

Originally Posted by Wakko47

Oh ok. THanks for the lesson.

11 yr old thread not a record but respectable

Did you do the test with the throttle held wide open

It makes a difference

WP

Jun 17, 2024 | 09:09 PM

#22

Trfsrfr

Intermediate

Joined: Oct 2018

Posts: 38

Likes: 3

From: Phoenix, AZ

My bad...

Quote:

Originally Posted by Wakko47

11 year old thread. 115/111 seems pretty low. That was a hot motor?

Quote:

Originally Posted by WP50

11 yr old thread not a record but respectable

Did you do the test with the throttle held wide open

It makes a difference

WP

No, I forgot to do it WFO (been awhile since I've had to do a comp test), but I did retest WFO, and I have 174 psi on the rear and 177 on the front.
Interesting that it makes a 60 psi difference...

Jun 18, 2024 | 07:43 AM

#23

WP50

Seasoned HDF Member

Joined: Apr 2011

Posts: 6,185

Likes: 2,134

From: W. Texas

I'd say your good to go now

WP

Jun 20, 2024 | 01:48 PM

#24

Wakko47

Road Warrior

Joined: Feb 2012

Posts: 1,719

Likes: 91

From: Florida

Quote:

Originally Posted by WP50

11 yr old thread not a record but respectable

Wasn't me that bumped it.

Jun 20, 2024 | 01:57 PM

#25

WP50

Seasoned HDF Member

Joined: Apr 2011

Posts: 6,185

Likes: 2,134

From: W. Texas

Quote:

Originally Posted by Wakko47

Wasn't me that bumped it.

Yea but I saw your post first lmao. rather than Trfsrfr.

Hell I think I bumped one that was 12-13 yrs old.

WP

Sep 19, 2024 | 05:22 PM

#26

Lando Evo

Intermediate

Joined: Sep 2024

Posts: 35

Likes: 25

From: Tulsa OK

Quote:

Originally Posted by WP50

11 yr old thread not a record but respectable

Did you do the test with the throttle held wide open

It makes a difference

WP

Do you have to disable the ignition and drain fuel out of carb? Some YouTube video said you should do that.

I'm trying to get accurate reading on my 99 FLSTC after doing top end rebuild,10:1 wiseco pistons, and EVL 3020. 20k miles.

And do these pics have anything concerning? I boroscoped them after a few hundred miles on rebuild. I had the cylinders honed and then the hastings rings didn't need to be gapped at all. Might have been a little over gapped if anything. I had to fit pistons and rings with my hands, ring compressor was **** and wouldn't compress them evenly.

Thanks for any advice.

Sep 20, 2024 | 11:32 AM

#27

t150vej

HDF Community Team

Joined: Dec 2005

Posts: 5,404

Likes: 2,605

From: NC USA

Quote:

Originally Posted by Lando Evo

Do you have to disable the ignition and drain fuel out of carb? Some YouTube video said you should do that.

I'm trying to get accurate reading on my 99 FLSTC after doing top end rebuild,10:1 wiseco pistons, and EVL 3020. 20k miles.

And do these pics have anything concerning? I boroscoped them after a few hundred miles on rebuild. I had the cylinders honed and then the hastings rings didn't need to be gapped at all. Might have been a little over gapped if anything. I had to fit pistons and rings with my hands, ring compressor was **** and wouldn't compress them evenly.

Thanks for any advice.

No. Simply remove both plugs. stick them back into the wire and lay it on, or near the head. Slowly open the throttle all the way before testing compression.

Cylinders look totally normal. The wide white stripe is from heat and you'll notice it's position coincides with the cylinder stud. They simply can't cool as well there. The darker lines are somewhat from heat but would for the most part disappear from sight if you took the head off.

Looks like you're right on the edge of lean which is where they run and pull the best, but that can cause some heat build up under certain conditions.