6BTA 5.9 – Loss of top end power

[Randy Crawford]

Just recently my starboard motor would not exceed 2200 RPMs. There was no additional acceleration the remaining half of throttle. Also noticed a not normal amount of soot build-up in Aft cockpit area.  I checked the turbo, it spins freely, air filter is new/clean and fuel filter were changed in spring.. However, I did notice the the Racor primer bypass valve would not get hard (maybe it needs a little blue pill!). So, I took it apart and notice it was stuck in an open position. I replaced the valve and primer now works fine, but i have yet to put the motor under load. 

So, do you think the primer bypass valve is the culprit for loss of top-end power? No idea when I’ll get a chance to test, but am hoping to get others feedback – bad turbo, bad injectors or ?????????

Topic

[Randy Crawford]

Here are some pics you requested…

[Randy Crawford]

Port: 46076016

Starboard: 46076534

 

[Tony Athens]

Did I miss this?  What exact 6BTA’s are these?  Post serial numbers..

 

 

[Randy Crawford]

2,750 RPMs is the usual at WOT – not reduced. 

[Rob Schepis]

What exact 6BTA?

Was 2,750 your usual WOT or is it reduced ?

Post some pics of the engines and exhaust.

[Randy Crawford]

We seatrialed and found some improvement – At WOT, we can get to 2750 RPMs on both motors, however, Starboard turbo does not spool up as fast as the Port. At about 2200 RPMs the Starboard turbo lags and slowly picks up at a much slower pace than the Port. Any suggestions?

[Tony Athens]

seatrial and report back

[Author]

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