mercuiser 888 wont idle below 1000 rpm

[mauro.]

do you guys think 24 decrees is to much advance with 8 decrees initial?

 

[alldodge]

do you guys think 24 decrees is to much advance with 8 decrees initial?

No
and set timing at what is in manual

 

[mauro.]

ok thanks I will play around with it until it does not knock or loose power as I don't have a timing light so most likely initial will be what manual says 10 decrees BTDC

 

[nola mike]

Get a

ok thanks I will play around with it until it does not knock or loose power as I don't have a timing light so most likely initial will be what manual says 10 decrees BTDC

Get a timing light. Absolutely no way to time an engine otherwise.

 

[Scott06]

it does have an idle screw that I have put at 1and 1/2 turns in as soon as it started to oppen the buterflys

Yes it should open them slightly, set the screw whee it will remain idling about 650-700 rpm. Iif completely closed it wont idle . As outlined you need to do this while setting the timing and idle mixture

 

[mauro.]

hello thanks for all the help so far I had the boat on the water first time today but engine wont go above 2000 rpm under load and there is a metallic clicking sound that I think is coming from the coil. Idle is still not perfect and you can smell unburnt fuel coming from exhaust plus it is smoking white smoke out of the Roker arm covers and left cylinder head gasket is leaking a tiny bit of water it seems like for it is slightly moist. Do you guys think that is the issue? I will have to talk to marine parts supplies for they sent it from Sierra it is all torqued to specs.
Thank you for all the help so far
Mauro

 

[mauro.]

oh and by the way operating temp is at 70 decrees Celsius so cooling is working properly
Thanks for the help appreciate it!

 

[mauro.]

and its me again too many symptoms to list haha. so when I try to put it in gear below 800 rpm it will stall the engine. Maybe something wrong with stern drive? any how wont bug you guys any more will wait for replies

 

[alldodge]

hello thanks for all the help so far I had the boat on the water first time today but engine wont go above 2000 rpm under load and there is a metallic clicking sound that I think is coming from the coil. Idle is still not perfect and you can smell unburnt fuel coming from exhaust plus it is smoking white smoke out of the Roker arm covers and left cylinder head gasket is leaking a tiny bit of water it seems like for it is slightly moist. Do you guys think that is the issue? I will have to talk to marine parts supplies for they sent it from Sierra it is all torqued to specs.
Thank you for all the help so far
Mauro

The motor is not burning all the fuel. Carb needs adjusted or rebuilt again, plugs not firing correctly, low compression.

White smoke and head leaking, check the oil level. Might have water going in the block.

The ticking is most likely a lifter, needs adjusted or collapsed

 

[mauro.]

alright will have a look thank you so much
mauro

 

[mauro.]

do you think the power valve is letting in all that fuel for it back fired quite hard when I started it up the firs time
thank you
Mauro

 

[alldodge]

So far signs are not showing a simple answer. If you hadn't said the motor was torn down and put back together, carb rebuilt I would advise to do just that.

If power valve is leaking then this would cause excess fuel, but so would a mis-adjusted carb do same thing.

Back fire is caused by incorrect timing or intake valve getting stuck open. If valves are mis-adjusted then this can keep valves from fully closing

 

[mauro.]

how can you adjust the carb at wot?
the back fire happened before timing was adjusted

 

[alldodge]

how can you adjust the carb at wot?

You cannot

 

[mauro.]

so what would you recomend to do

 

[mauro.]

and how do you adjust/test the lifters/valves?
thank you for helping me out
Mauro

 

[nola mike]

Did you check compression yet?

 

[mauro.]

I did before starting they were all to specs but I willtest it again now that it has run to see if there is a difference

 

[alldodge]

Compression test and then leak down test
See if you can rent a leak down test gauge, then need compressor and air chuck for cylinders

 

[mauro.]

I will do another compresion chek as soon as I can I cant rent a leak downcompression tester