Suggstion for tune up on the sonic?

[kyboy1020]

Twin 454's. I spent the whole first season with her just seeing what and wasn;t running right. Now its time to start tearing in to it some. I have fixed a million small things and plan on doing a full motor tune on it this winter. Then if all goes well we will pull and mod the motors next winter. Here is my list o far of things to change some seem way bobvious but lsited anyways.

1)New serpentine belts Any suggestios on brands POP (point of purchase)?
2)New filters (gas and oil)
3)New MSD 8.5mm Spark Plug Wires
4) New spark plugs... Any suggestions on brand/model POP???
5)New cap and rotor? Any suggestion on brands POP
6)Rebuild carbs
7)Drain drives and refill
8)Replace shifter and throttle cables... Suggestions on brand/model POP

Is there anything else anyone would add to this list? I have had any major compliations but know that these things weren't maintained wel before. What about the timing on these motors? Is it worth bumping? I am going to check the timing on both motors also.

[kyboy1020]

Bump

[RaggedEdge]

Few other things .........

Pull drives and check alignment.

Check gimbal bearing while drives are off.

Check coupler and shaft for wear, and grease U-joints if they have the fittings, in any case check them at least.

Pay attention to the magnetic drain plugs when you change gear lube, if you see filings on them have them checked by a drive guy.

Pull the drive bottles and clean any crud out of them before you refill the drives.

My 454 Mags, 525 SC's, and HP500's all used AC plugs from Merc. I always just used the same plugs and had good luck. Leave the timing where Merc says it should be, they have these motors pretty well figured out in their stock configuration.

[Griff]

1. Take your belt to Napa and have them match it
2. There's a 100 threads on oil and filters. I run Mobil 1 15-50wt and Mobil 1(M1-302) filters. I use merc water sep filters. You can pretty much only get merc stuff from merc dealers.
3. Plug wires....Summit Racing or Jegs
4. NGK spark plugs
5. I use Merc ignition parts. Try boatfix.com(they carry some merc parts) or www.mercruiserparts.com
6. If the carbs are not broke, leave them alone.
7. Fill from the bottom of the drive
8. If they are not sticking, then no reason to replace. They are not cheap.

Other stuff--
Change seapump impellers in the Spring
Pull drives and check alignment and grease U joints
Grease Gimbal bearing

[dyno]

have a good engine builder do a leak down test on it ,if you dont know the history you may save yourself alot of greif if they are shot...my .02

[kyboy1020]

Carbs aren't broke just need some cleaning and tuning I think...and the shifter ables are super stiff and hard to shift from f to r... I figured I would replace them all in one shot since they seem to be the original 89's. Just like to fix things in sets so I can narrow down problems in the future easier

[kyboy1020]

Today I purchased mercruiser performance oil filters and fuel filters... Ngk u5 spark plugs, new belts, new mercruiser starter, 16 gallons of marine antifreeze.... Now just need cap and rotor I beleive

[sunchaser796]

Checking the engoine alignment on a Sonic, don't worry about it cause they all use aluminum angel brackets on the front and there is'nt much you can do about it. If the alignment is eating the yoke on the drive then replace the coupler with a high performance version. Where I work, we have three Sonics in the barn right now with two more coming by the end of the month. The tree in the barn are all triples 1 w/ 575, 1 w/750 and the other w/ 900's and the other two are twins with bot inovations and konrad drives. So bottom line is I do know Sonics and how they are built. Need anymore info e-mail me @ sunchaser796@comcast.net..

[Griff]

Originally Posted by kyboy1020

Carbs aren't broke just need some cleaning and tuning I think...and the shifter ables are super stiff and hard to shift from f to r... I figured I would replace them all in one shot since they seem to be the original 89's. Just like to fix things in sets so I can narrow down problems in the future easier

Disconnect your shifter cables where they connect to linkage at the engine and then see if they are hard to move then. Chances are its your lower shift cables or the linkage in the drives.

What NGK plugs?????????

[kyboy1020]

Yes sir we did that... Drives are completely rebuilt. I beleive the NGK are u5's....is there a different one u prefer griff?