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671 TIB Smoking after cruise

"I have twin 671 TIBs in a 44&

"I have twin 671 TIBs in a 44' sportfish. Motors were majored 150 hrs ago. Stbd engine has been smoking, even after running at cruise for extended periods. Detroit mechanic found bad injector and replaced. Smoking problem persisted. Mechanic returned to do compression checks on all cylinders. Readings on all cylinders were within 6 pounds of 475 psi - mechanic said these were readings of a new engine and thereby dismissed any thoughts of blow-by. We still do not know why this engine still smokes. Could there be slop in the wrist-pin on the piston? Could a blower be causing this? Any help would be appreciated."
 
john
had a 692 majored last


john
had a 692 majored last year and had to go thru 12 plus injectors to get 6 good . reliabuilt parts have issues . i could tell when one went bad when i saw smoke and slight fuel out the exhaust port
 
"Thanks much George...My mecha

"Thanks much George...My mechanic, a life-long Detroit guy, said he used to have a shop that would do a full test on fuel injectors checking all the specs, but that shop is no longer in business...He said in a perfect world, you would replace all of them with a matched set of injectors, but it's unnecessary and costly"
 
"No smoke at all at cruise spe

"No smoke at all at cruise speed, but starts to smoke a few minutes after bringing back to idle speed. There is also a minute fuel slick coming out the exhaust port at idle. The smoke appears to be blue. Thanks Marvin"
 
"good possabity that you have

"good possabity that you have glazed liners.have your mechanic remove air box covers and turn engine by hand and inpect each liner,if glazed they will have a gold color on the cyl walls."
 
WELL YOU NEVER DID TELL ME WHA

WELL YOU NEVER DID TELL ME WHAT COLOR SMOKE BUT I ASSUM ITS WHITE AND THAT WHOULD BE UNBURNED FUEL.
 
"He said it was blue, Marv, in

"He said it was blue, Marv, in the post just after your first one. Blue means you are burning oil. Glazed cylinders or worn/broken rings would cause that."
 
"And I forgot... Yes, a bad se

"And I forgot... Yes, a bad seal on a turbo can let oil into the intake and cause blue smoke. If it's truly oil smoke, the exhaust will also smell different than the non smoking engine."
 
"[b]hey guys i have 2 671 low

"hey guys i have 2 671 low profile 400 hp engines i cant find a pair or alternator brackets in the whole world can anybody help me out,its to the point i dont care how much they cost, i just restored a 34 striker offshore fishing machine and 2 brackets are delaying me and im losing sleep over nite. thanks jeff fisher."
 
"JOHN, I HAVE THE SAME PROBLEM

"JOHN, I HAVE THE SAME PROBLEM WITH ONE OF MY
671 TI'S.BLUE SMOKE AT START THEN GOES AWAY WHEN IN GEAR.ENGINE SEEMS TO RUN GOOD.COMPRESSION CHECKED GOOD ALSO.REPLACED TURBO RECENTLY ALSO,SO THE SEAL SHOULD BE GOOD.TESTED INJECTORS-GOOD.MECHANIC IS STUMPED AND SO AM I.

MARVIN,IS IT POSSIBLE TO STILL GET GOOD COMPRESSION READINGS WITH GLAZED LINERS OR CRACKED RING?"
 
"Dave-
Strangely the smoke go


"Dave-
Strangely the smoke goes away while at cruise, but returns about 5 minutes after coming back to idle - not sure if you are experiencing the same thing or not...Let me know"
 
"JOHN-
LIKE I SAID, SMOKES AT


"JOHN-
LIKE I SAID, SMOKES AT IDLE NOT IN GEAR.SMOKE GOES AWAY IN GEAR AND AT CRUISE.SMALL FUEL SLICK ALSO AT IDLE.THIS HAS BEEN GOING ON FOR 2-3 YEARS NOW.MY MECHANIC SAYS DONT WORRY, BUT IT BOTHERS ME.
I HAVE NOT PULLED MY AIR BOX COVERS YET AS THEY ARE NOT EASY TO GET AT.THE EXHAUST MANIFOLD NEEDS TO BE PULLED TO HAVE ENOUGH ROOM.
SEEMS TO ME, COMPRESSION WOULD BE LOW IF THERE WAS A CYLINDER ISSUE? I DONT KNOW IF IT COULD BE A BAD VALVE SEAL LETTING OIL INTO THE EXHAUST? I'M SURE MARVIN COULD CHIME IN?"
 
Same thing I have - a little s

Same thing I have - a little slick out of exhaust port. I had compression in the "new" range on every cylinder. The only thing we haven't checked is the possible "glazing" of liner(s) and the turbo seals. I suspect that will be the next thing we check. Blue smoke is indicative of oil burn; which is bothersome to me
 
"Finally discovered the proble

"Finally discovered the problem on last cruise. Engine was only running at 110 degrees even after cruise. Suspected a thermostat stuck open, and upon removal, confirmed that it was in fact stuck open with a piece of debris. Smoke the result of operating temp severely low"
 
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