"Tune up"

[Top Shelf]

Got bored doing my budget on my last flight...so I re-read my engine survey stored on my laptop. It's 18 months old and I keep picking up stuff I'd forgotten about. One comment was both motors should be "tuned up".

What exactly is a tune up on a DD 8V92TAC (2300 hrs)? I'm guessing injectors cleaned, air box cleaned, rack re-set etc....but it's all a guess. Any insight is appreciated. thx.

[Genesis]

1. Check cold exhaust valve clearances.
2. Warm up engines.
3. Recheck hot clearances. Make sure engines stay hot during this test (not always easy)
4. Check governor gap and adjust
5. Check injector racks, adjust.
6. Set throttle delay.
7. Check high idle, adjust. If off more than 50rpm, go back to (4) and start over!
8. Check and set idle and buffer screw.

If you haven't already, I'd also pull and clean ALL the coolers, with the possible exception of the oil cooler.

[pirate1960]

dont forget the injectors. If ou are in there, pull the injectors and go have them tested. You just might be surprised what you find. A MUST for any tune up with that many hours.

[mikep996]

And get the DD service manual for the engine; it describes all the adjustments you will be making and the appropriate specs.

[double eagle]

first of all ....
how is the boat running now...
does it start good..
how much smoke if any...
how many hours per yr...
if aint broke....well you know
bill

[Genesis]

... even if all appears ok.

None of those checks are invasive or require CHANGING anything. Exhaust valves in particular are critical; if they're too loose you can have a keeper come apart under load, and if too tight you can burn one. Either is a very expensive problem.

Pulling all the injectors is not something to do unless you have a reason to do so. Contrary to popular belief unless you get crap in them (due to bad filtration, water in the fuel, etc) injectors do not go bad for a very, very long time. Its fairly easy to damage the tips during removal and its even easier to get crud down the open holes or screw something up taking them out and replacing them, not to mention that if you yank 'em you now have to do a complete turn-up by the numbers.

Agree you need a shop manual, and a couple of special tools (injector pin-timing gauge, etc) None of this is expensive.

I go through the tune on my engines every year. I've yet to find things EXACTLY where I left them.

[Top Shelf]

Thanks for all the input guys. It sounds like given the time, I should be able to do this. Problem is I don't have the time, 3 or 4 different cities a week......and when I get home it's pretty much routine mait and fish and dive....

This also sounds like a good opportunity for a DD guy to skin me for $85 an hour portal to portal and MAYBE do the right thing.....

Anyone got a good mechanic reference in the Boca Raton / Ft. Lauderdale area? And any guesstimate realtive to "hours of work" to get this done.

I did check / clean all the coolers (except for oil) and temp is fine. So I think I'm good to go there. Thx.

[Genesis]

... should be one man-day of labor. No more.

That would include running the rack if its out of calibration, checking and setting valve clearances, etc.

If he has to get into injector R&R its going to take more time.

Florida Detroit Diesel is in that general area. I'd probably start there. Pull the floor for him so when he shows up he's got two big hunks of iron staring at him.

[pirate1960]

this cam e up in a conversation today with my mechanic. I would assume that you have had this boat for 18 months. This means you probably have no idea what has happened in thwe prior 2200 hours of operation of these motors. Don't bother setting the rack if you have no idea how much fuel each injector is delivering and what the spray pattern is. It doesn't cost much to have the injectors tested and this should give you piece of mind. The fun will be if you waste the money to get a mechanic on your motors and when he is doebn, he suspects injector issues. Guess what, open the valve covers again and start over halfway.

Do it right the first time, see what 2350 hours have done to your injectors, since they are very important to the correct operation of these motors.

THE PIRATE

[Traveler 45C]

3. Recheck hot clearances. Make sure engines stay hot during this test (not always easy)

Stays hot? You mean temps over 185F or will over 160F do?