5.7l 2bbl tune up

[greenwell001]

i was wondering what u merc gurus would consider a good tune up.....it a 5.72 bbl. in good shape, doesnt use oil , no knocking, and valve seals seam good. but just doesnt seam like she is as strong as she used to be...

side note: any suggestions on a little better than stock 2bbl or small 4 bbl as i prob can get one compared to the cost of getting mine rebuilt

 

[cr2k]

Re: 5.7l 2bbl tune up

A good tune up for anything is:

Properly set points (if equipped)
Properly set timing
Properly adjusted Carburetor.
Any valve adjustment if needed (usually not with everything running hydraulic lifters).
Good and Properly set spark plugs.
You might gain a little by slightly advancing your timing, but must be compatible with octane rating. i.e. more timing more octane or booster added. This will, however, affect your operating costs for fuel.

knocking, rattling noises form the engine are not good. even a little.

 

[Bondo]

Re: 5.7l 2bbl tune up

Ayuh,... What Vintage is this 350 Merc,..??
They've changed quite abit over the last 40 years ya know....

 

[greenwell001]

Re: 5.7l 2bbl tune up

bondo

it is a 350 merc....1996 non vortec 2bbl rochester, when i look on merc website cant find the 96 non vortec hp rating, but i have heard it is 210...merc doest list a 210 hp, but the efi version rated at 260, what do you think?

 

[Bondo]

Re: 5.7l 2bbl tune up

Ayuh,... An Edlebrock performer in 600/650cfm, on a matching manifold will put you around 250hp....
The Edlebrock is a carbon copy of the Merc/ Weber 4bbl. that Merc still uses...

 

[Don S]

Re: 5.7l 2bbl tune up

Go to the link below, and download Service manual #17 for your engine, and #14 for your drive.

http://forums.iboats.com/showthread.php?p=1693398#post 1693398

Cap, rotor, and spark plugs (NGK or AC, do not use Champions) are about all you need for parts for the tuneup, unless you see problems with the plug wires deteriating or corroding.
There is a special procedure for checking the timing on the Thunderbolt V ignition so read it carefully before you move the distributor. You really shouldn't have to move it, but you do need to verify things are wroking.
The compression test bubba mentions is important.
Here is the SB on the compression test. http://www.boatfix.com/merc/Bullet/97/97_25.pdf
Also make sure the flame arrestor is clean. I have seen them clogged up so bad it was surprising the engine ran at all.