1999 Volvo penta 4.3 GLPWTR

[Jthao]

Hello all,

Why is my spark plugs in cylinder 1and 5 tip of spark plugs chip of a little piece of metal off? See the picture
I hope someone have an answer to help me out

 

[cobalt1999]

Looks like you are using the wrong length spark plug, that chip could be a valve strike.
Why is there so much black on the threads?
I think you should have a short reach plug going by the color pattern of the threads.

 

[Jthao]

Hello cobalt1999,

I think the black is from running a little too rich might have to adjust the carb.
I just using the spark plugs that provided with my boat engine serial# 4110179509.

 

[cobalt1999]

Looking up spark plugs for that motor shows that it calls for a long reach plug.
Was there any engine work done?
I have no other ideas.

 

[Jthao]

Hello cobalt1999,

Yes just replace all gaskets from head, exhaust and intake manifold only. Does timing have to do anything with this spark plug chip off a little?

 

[alldodge]

Both 1 and 5 had the same exact missing piece?

 

[Jthao]

Hello alldodge,

1 and 5 have different Missing piece. 1 just have a around maybe half missing of the 5. Attachment picture is the 5 cylinder.

 

[Scott Danforth]

from the soot tracking on the threads, I would say your motor is not a 1996 and later requiring the long reach plugs

how many intake manifold bolts do you have? 12 or 8?

 

[Jthao]

Hello Scott Danforth,

I have 12 bolts on the intake manifold. 6 bolts on each side.

 

[alldodge]

Hello Scott Danforth,

I have 12 bolts on the intake manifold. 6 bolts on each side.

That's a non-vortex motor and should have regular plugs MR43T
Someone swap the motor out

 

[Jthao]

Hello alldodge,

thanks for the information! I did not know that all I know is that when I enter the engine serial number it keep coming with the long plugs. I will change to the MR43T short plugs.

also thanks to Scott Danforth.

Thank you everyone for the help!

 

[Scott Danforth]

someone installed a 1995 or older motor into your boat. not only do you need the shorter plugs, you are also down on power

 

[Jthao]

Thanks Scott Danforth for the info!

 

[Jthao]

Thanks Scott Danforth for the info! What about timing how do I do mine timing on this engine? It has a 4bbl carburetor.

 

[Lou C]

Lucky that you noticed that! So you have an older pre Vortec engine which is a bit less powerful that the Vortec design and takes the short reach plugs.