Optimax 150 stalling

[domB]

I have a 2003 150 optimax that stalls sometimes in
neutral but mostly when shifting in gear.
Ive replaced fuel pick up line, bulb.
Im thinking to replace the fuel pump but i know it has 2 electronic pumps. Any advice would be greatly appreciated.

 

[racerone]

Step #1 is a compression test.---Post actual values here. ----Test fuel and air pressures.

 

[domB]

Compression test was
1. 80
2. 80
3. 80
4. 55
5. 80
6. 80

Fuel was 78

 

[domB]

Those are the brand new spark plugs

 

[racerone]

Looks to me that this motor needs major work.-----Remove cylinder head and inspect the cylinder with 55 PSI.

 

[birkato]

Compression test was
1. 80
2. 80
3. 80
4. 55
5. 80
6. 80

Fuel was 78

55 psi is way too low for compression; something is wrong there. Even 80 psi is on the low side; however, if they are all at 80 that is maybe OK.

 

[domB]

I will take off the cylinder heads and see what it looks like

 

[domB]

Found this under the cowl, any idea what this is?

 

[domB]

Opened up

 

[domB]

Any advice?

 

[racerone]

Have you determined why that cylinder has 55 PSI compression ?----Cylinder wall scored ?

 

[domB]

No, everything looks fine under the cylinder head i think...someone told me the problem might be the reeds. I did look in the exhaust manifold and its caked up in carbon.

 

[flyingscott]

Reeds will not cause low compression.

 

[domB]

Any suggestions?

 

[racerone]

Reeds have nothing to do with compression in the cylinder !

 

[domB]

Does this gasket look bad? Far right is the low compression

 

[domB]

Dont see any scoring so rings should be ok?
Lol this is my first time doing this