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318 rebuild noise

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RUSSA

New member
1983, 318 SINGLE SCREW ON A 1983 26FT SISU
This engine ran like a top for 16 years I have owned it.
Over 3500 hours on it.
Being proactive, last year had the engine rebuilt.
Also all new manifolds exhaust, elbows and risers.
Since 1983 this boat never had mufflers and had great mellow sound.
Since rebuild very noisy exhaust.
Also can not get top rpm 4100, getting 3300, and same prop as always.
Have had timing check and recheck, put new distributor this year.
Any ideas?
RUSSA
 
RUSSA said:
1983, 318 SINGLE SCREW ON A 1983 26FT SISU
This engine ran like a top for 16 years I have owned it.
Over 3500 hours on it.
Being proactive, last year had the engine rebuilt.
Also all new manifolds exhaust, elbows and risers.
Since 1983 this boat never had mufflers and had great mellow sound.
Since rebuild very noisy exhaust.
Also can not get top rpm 4100, getting 3300, and same prop as always.
Have had timing check and recheck, put new distributor this year.
Any ideas?
RUSSA
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I would put it all on the mechanic who rebuilt it,I'm sure you spent a pretty penny having all that work done.When you get it back it's supposed to run right.
 
like tahoerover said,If you put a new timing chain on, there are 3 keyways on the napa melling chains stock,advance,retard the cam timing,ask about this
 
T & t
now this sounds like something to work on,first time I have heard this,NONE OF THE EXPERTS ON THE DOCKS,ever mentioned this.
does engine have to come out to correct?
russa
 
You will need to remove the timing cover from the front of the engine. I hope you have the room, and it should only take 2-3 hours to do the job.
 
Best way to be sure is to slip the damper pulley back on and rotate the crank to the TDC position. (The timing chain MUST be in place as you do this.) Next, remove the left valve cover, and eyeball the intake and exhaust valves on # 1cylinder (front left). (THis is the cam's "split overlap" position.) At TDC, the two valves should either be closed or just slightly open, and that amount of opening should be EQUAL. If not, try another keyway in the timing gear until you get it right.

This is called "degreeing in a cam"; we racers do it all the time.

Jeff

PS: If one of the valves is way open, rotate the motor one full turn and try again.
 
Check and double check all the electrical.

Read your plugs.

And make sure you check that firing order b-4 u rip and tear!

A compression test may help.

Was the cam replaced? If so, with what profile?
 
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