In the OMC shop manual they have the GM procedure for adjusting the preload or the depth of the plunger of the hydraulic lash adjuster....I did mine that way, had no problems even though it was the first time I ever did it.
Something there doesn't seem right. Is the # you posted the casting #?
http://machineworldny.com/asp/CylinderHeads.aspx?type=A&cno=10238181
I plugged in that # and it looks like you have the right heads for your range of model years
What's the block casting #? I see you have the later model...
if you look at the bottom of this pic you can see what I'm talking about...that little hook on the wire for the needle valve does not go in either of the two holes, it just gets clipped on the side of the float arm.
Hopefully you can get at those starter bolts at the bottom rear starboard side. Can be really tough on some boats. On mine I pull out the rear seat on that side & remove the battery. Then it’s do-able.
If you replace get a nice modern PMGR starter (I like ARCO) & get their bolt kit. They must...
Also might check float to see if it absorbed fuel. If you’re buying a rebuild kit get one from Cliffs High Performance Quadrajets. He has better quality parts esp the accel pumps. When installing the float make sure to get the little clip in the right place (do not put the hook in the holes on...
I thought these changed when they went to the non-adjustable valve train. A 1995 should be pre vortec IIRC. Non adjustable was on Vortec only correct? That & roller rocker arms. When I did mine I used the factory spec of 1 turn after zero lash.
If the fuel line dips below the level of the tank, an antisiphon is required.
On my boat this was a problem, the engine would start and rev in neutral just fine but would not plane out the boat. I went through the ignition and carb, nothing really amiss, took it to a good marine mechanic and...
PS
I'd like to see what the spark plugs look like, good engine vs the one that is surging.
blistered white electrodes, fuel starvation...float too low....anti siphon clogged...
black electrodes, maybe choke not staying open float too high, grit in needle valve
one last thing I'm assuming...
I'm one of the few who has an old breaker points & mechanical advance distributor you can check it with an advance timing light....
old school tune up circa 1966 tech lol. Glad I didn't throw out my old tools. I have a couple of spare 4.3 distributors, new points plate and new advance springs.
How are the 2 engines plumbed from the tank? Two lines coming off the tank, one for each engine? I've never had a twin engine boat but I think with 2 separate lines each should have their own anti-siphon valve. The whole point of it is, to prevent fuel from siphoning out of the tank if the fuel...
Start at the beginning of the fuel system, anti siphon valve on the fuel tank, & fuel tank vent.
If the anti siphon valve is corroded internally and sticking, or is partially blocked with crud this can happen
When you installed the new Holley, did you check the float setting? Their quality...
Carefully applied heat and a cotter pin extractor.
You can also try one of the many penetrants like freeze off, kroil etc.
I used this tool removing the 4 cotter pins from He11 when I replaced my steering actuator on my '88 Cobra and those weren't even corroded!
sure beats this abomination:
https://www.mercruiserparts.com/bam/subassembly/31527/16591/150
plus:
https://www.mercruiserparts.com/bam/subassembly/31527/16591/140
and:
https://www.mercruiserparts.com/bam/subassembly/31527/16591/220
add up all of this, you could have paid for a good portion of a...
Rubber impellers must be lubed
When I do my first start of the season I put on the muffs & turn on the water. Then I disconnect the raw water intake hose & fill it full of water this puts water right in the impeller housing. This works perfect it primes instantly.
Instead of that Rube Goldberg-ish maze of hoses & plastic they SHOULD have just made at least a half closed cooling system STANDARD!
If you want to get a headache take a look at the parts breakdown on a modern Merc 4.5 just for the raw water cooling system. Somehow my old OMC Cobra made do with...
These things seem to work OK when the engine is new but as it ages, cast iron naturally sloughs off rust flakes, that wind up clogging drain ports. That is the problem with these systems.
On my boat I reconfigured the rear of the boat to make the engine more accessible so that I could have...
as long as the base under it is in good shape, all you need is the foam and a staple gun. Not a hard job, I had to replace the bases on most of the seats on my boat and the big sunpad as well.