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rl65028

Contributing Member
Bought an overhaul exchange 4.3 mercruiser from US engine on line. I had some warranty issues I wanted help with from owner MR. Charlie Silvers. Most arrogant, combative, nasty human being Ive ever done business with. It took a credit card dispute just to get my core deposit back. My issues were oil consumption, Popping sound out intake at times, and Low WOT rpm. I ended up changing carb I suspected too rich and it seems popping sound is resolved. (been through timeing many times) The jury on oil consumption is still out. The WOT RPM remains. Prop cant get much smaller 14.5 X 15 on a 21 ft boat with 8.5 ft beam 1992 celebrity fishawk. Ive never seen 4400RPM this engine or previous. 4000 max. Also id like to add PCV valve But there doesn't seem to be any port on this 12 bolt intake manifold. Any one have any suggestions?
 
Popping was most likely from a lean condition.

I would do a compression test and a leak down test on the engine. When you get those numbers you will know which direction to go in.
 
rl65028 said:
Bought an overhaul exchange 4.3 mercruiser from US engine on line. I had some warranty issues I wanted help with from owner MR. Charlie Silvers. Most arrogant, combative, nasty human being Ive ever done business with. It took a credit card dispute just to get my core deposit back. My issues were oil consumption, Popping sound out intake at times, and Low WOT rpm. I ended up changing carb I suspected too rich and it seems popping sound is resolved. (been through timeing many times) The jury on oil consumption is still out. The WOT RPM remains. Prop cant get much smaller 14.5 X 15 on a 21 ft boat with 8.5 ft beam 1992 celebrity fishawk. Ive never seen 4400RPM this engine or previous. 4000 max. Also id like to add PCV valve But there doesn't seem to be any port on this 12 bolt intake manifold. Any one have any suggestions?
Click to expand...

Thanks Chris. Actually I have done compression. all cyls were between 115 and 125. I read they should be 180 but I attributed to the fact I forgot to wide open throttle, maybe couldn't suck the air.
 
Thanks Chris. Actually I have done compression all cyls were 115 to 125. I read they should be 180 but I attributed to the fact I forgot to wide open throttle maybe couldn't suck the air.
 
I would do a compression test and a leak down test on the engine. The leak down test will tell a more accurate story. The numbers you are showing will not improve with WOT. If your compression gauge is accurate, this engine is in poor condition.
 
the combo of low wot rpm and popping would have me checking the cam timing if it were my boat. chain could be off by 1 tooth. Would also explain lower compression.

I would do a valve adjustment using a remote start switch, and a compression gauge first though. Misadjusted valves are a more common issue.
 
hystat said:
the combo of low wot rpm and popping would have me checking the cam timing if it were my boat. chain could be off by 1 tooth. Would also explain lower compression.

I would do a valve adjustment using a remote start switch, and a compression gauge first though. Misadjusted valves are a more common issue.
Click to expand...

TY hystat don't think cam is off however. seems to run and idle smooth. Popping resolved w new carb. basically sick of crawling around in bilge which is why I bought new engine from US engine. they're real crap. I may take it somewhere over winter. Timeing is set to 35 btdc @ 3000 rpm. starts easy sounds normal maybe light tap just till oil warms. valves could be too tight however. Dunno Dunno sick of it. Compression was weird however. First I pulled 1 plug which was black and pulled 180 compression on that cyl. Only one I checked. then I changed carb and did compression on all 6 forgetting to WOT. I got #s I posted. Ran it 25 miles yesterday used a quart on way out but none comeing back. RPM was low comeing back due to sea conditions. if consumption continues I may pull and replace with new and chalk it up as a loss.
 
Timing is very wrong ,should not be tapping untill the oil warms up. what wt oil is in it? Almost all engines require a valve adjustment,especially new ones. Did you pre-oil before firing?
Comp numbers seem low ,but that could be the rings not seated yet and thats why oil consumption is high.
 
Also id like to add PCV valve But there doesn't seem to be any port on this 12 bolt intake manifold.
Click to expand...
Look for a plug rt behind the carb base rise on the manifold. You'll need to install a breather cap on one valve cover...vent hole will need enlarging. May also need a baffle under the PCV valve to keep from blowing oil into the valve...not positive but look at the valve cover.
 
To the OP here.
This could be a tough row to hoe.

Side stepping for a moment............. If memory serves me, one of our BOC members had an issue with this same company a few years back.
Unfortunately, I cannot verify this due to a new BOC forum format that has rendered the archive search feature unusable.

However, most any of us could take a new engine from MM, US, Merc, Volvo Penta, Indmar or PCM, and do an incorrect set up, and could cause engine damage to it.
I.E., incorrect run-in procedure, incorrect ignition timing, incorrect F/A ratio, over-heating, etc.

Most any of these engine suppliers are going to want some extensive and forensic information from us, before they roll over and authorize a warranty claim.
The burden of proof is often on us.

The fact that you were treated disrespectfully by the US rep..... is another concern.
IMO.... No company should represent themselves in this manner.......... Not good for biz.... especially with forum activity these days.


All I can say is that you've been offered some good suggestions here.
Take heed!
I wish you the best.


.
 
rl65028 said:
TY hystat don't think cam is off however. seems to run and idle smooth. Popping resolved w new carb. basically sick of crawling around in bilge which is why I bought new engine from US engine. they're real crap. I may take it somewhere over winter. Timeing is set to 35 btdc @ 3000 rpm. starts easy sounds normal maybe light tap just till oil warms. valves could be too tight however. Dunno Dunno sick of it. Compression was weird however. First I pulled 1 plug which was black and pulled 180 compression on that cyl. Only one I checked. then I changed carb and did compression on all 6 forgetting to WOT. I got #s I posted. Ran it 25 miles yesterday used a quart on way out but none comeing back. RPM was low comeing back due to sea conditions. if consumption continues I may pull and replace with new and chalk it up as a loss.
Click to expand...

Ayuh,.... It Sounds like this motor wasn't set up properly,...

Puttin' a faulty carb/ induction on a brand new block, is Still a Bad induction system,...
Donno what killed the original motor, but runnin' this 1 with a Lean condition, may well have already burnt the valves,...
I say a Lean condition, as that's the most common cause of the poppin', 'n backfirin' yer hearin,...

Ya don't need a PVC valve, ya just need to Fix whatever's now wrong with the set up,...
 
RicardoMarine said:
Chris... do I need to give you a cyber spanking? ;)

Just a friendly FYI.... TA numbers are meaningless without an associated RPM.
IOW, the 22 * that Chris mentioned, must be associated with an RPM.

Perhaps Chris can add that info for you.


.
Click to expand...

It's the 8 degree base with the Thunderbolt IV Module making up the other 14 degrees. The Module will decide when total timing is achieved.


He needs to check his module and make sure it is stamped 14 degrees.
 
Docksidemarineservices said:
It's the 8 degree base with the Thunderbolt IV Module making up the other 14 degrees. The Module will decide when total timing is achieved.

He needs to check his module and make sure it is stamped 14 degrees.
Click to expand...

Chris.... I don't disagree at all. But what are the chances that a module may not be delaying the spark advance correctly? I don't know the answer to that.
I say "delay" because this is how the module functions.

Example:
At low RPM, the module is fully delaying the built-in 14* of electronic spark timing advance.
Our "BASE" advance is determined by the distributor housing's position.

As RPM increase, the delay becomes progressively lessor, until finally there is no more delay.

I realize that you know this... I'm just tossing it out for the others.





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