Engine imbalance

[Guest]

I've been keeping the engines running over winter (Volvo AD31's), but I've noticed that off-load, one seems to rev much more freely than the other. Opening the throttles equally (to maybe 1/4 throttle) sees the starboard revs race ahead of port. To get the revs matched, I've got an inch or two difference in the levers.

Any ideas? PaulJS, I've sent you an email on another matter, BTW

 

[tcm]

Is this just a lever adjustment thing? There's an adjustment on the idle (nothing to do with the cables) and then pushing the lever opens the throttles. With slackness/tightness the two engines will have different revs at the same lever settings. Er, or am I missing the point...

 

[Guest]

No, last season they were pretty much in sync, then right at the end of the season, I lost power on stbd caused by a blocked filter. Cleared that, but now I have this balance thing. I never thought of checking the cables, but I can't see why they'd have slipped over winter. It also remains to be seen what they do under load, of course.

 

[mtb]

sounds like its sucking in air ,possibly manifold .
If you over heated the engine it could have caused the manifold to warp.
Mick

http://homepage.ntlworld.com/boats
I want a big steel ex trawler / tug v / cheap or swap for tug

 

[aztec]

what engines you got in there then? and what controls etc.

interested in stuff that needs mendin'

http://homepage.ntlworld.com/s.amos/index.html

 

[Guest]

Volvo AD31's with Morse controls. Pretty standard stuff, I think. If there's adjustment on the throttle levers, where would I look?

 

[tcm]

Re: cables

GW, be4 my cable went, it also strangely changed the lever angle. It could mean that the cable is stretching.

you can adjust them down at the engine end, amount of slack. Don't bog around with the morse levers themselves as right blimmin nightmare in there, unless u fancy a whole weekend poncing about. Or just bollox2 it - mine never excerly together at same revs. I'd leave it, but praps consider asking if the spare cables are the same port and starboard - and if they are get one as spare.

 

[Guest]

Re: cables

agreed, if I wanted exact sync, I'd get electronic control. But having the levers staggered by 2" clearly wrong. What's odd is that just off tickover, they're in sync. It's like one has more leverage than t'other.

 

[hlb]

Re: cables

Try reving the engines from the engine side of the cables and see if their the same there. If so it's cable adjustment needed. If not then its engine problem. But usually engines will rev off load even with problems so suspect cables or linkage.

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[Guest]

Re: cables

Thanks, will do. They both rev OK, off load, just way out of sync i.e. the first 1/8 of the throttle movement revs one to 1500 revs, but the other goes to 2500... To get them both pulling 2000 revs, the levers are 2" apart

 

[tcm]

Re: cable position, and edc

at neutral, the cables are entirely slack. The tickover setting on the engine adjusts that. The cables are totally uninvolved.

The cables pull open the throttles, tio lift revs above tickover. But the one for which u need to pull more has some slack. It doesn't pulll the cable until later than the first one. You could tighten that up. Or, ucd slacken off t'other. Get wife (with engines off) to put it fwd and so on and you'll see.

But, i wdn't bovver.

Incidentally, lectornix NOT nec the cleanest way to balnce revs, they say. Wiv got this differential guage which (on cables ) shows left/right which one is revving more even just a teensy bit, and (so they say) this is more accurate. So, more money saved there. AND my other rec'n of doing nothing means er I'd better not fix boats as a job.

 

[Guest]

OK, I think I have enuf on cable to take a good look around that department. What else might cause this, in the light of last season's probs with suspected fuel starvation. Air leaks? Iffy turbo? Blocked injectors? "Need new boat" Syndrome?

 

[tcm]

Re: reasons fior throttle position out

1. The cable stretched a bit

2. The man who does maintenance has put another cable on . It'll be in massive bill somewhere. Askimto put it straight.

3. The man who does maintence took it ouyt for a blast er seatrial, snapped the cable and hastilyreplaced it.

4. Boat indeed now has massive "newness" deficiency. Wholly unsatisfactory with slightly out of kilter throttles. Almost completely useless, in fact, and quite undriveable.

 

[Guest]

Re: reasons fior throttle position out

Doesn't that Soltron stuff supposedly rectify Newness Deficiency? Or am I thinking of Viagra again...

 

[hlb]

Re: cables

Theres a rod with two nuts on the end, that pull the throttles open. One might have loosened itself. Tighten it up if loose, till it nearly starts to move the throttle whatsit. But not quite.

No one can force me to come here-----------
----- I'm a Volunteer!!!

Haydn

 

[rich]

are your batteries fully charged. my alternator will slowdown one engine when the battery is low.

rich )

 

[Guest]

brilliant thought. The port engine charges the domestic bank, so it might be worth looking in to...

 

[BarryD]

Its the TekDek syndrome...

Have you completed fitting it? The same thing happended to KevB - he fitted TekDek (and new carpet) the throttles went a mm or two out of line - POW new Sessa Oyster with associated bills....

Through difficulties to the bar (IMHO / FWIW / NWGOI)

 

[tcm]

Re: nah?

but but yerv gotta massive engine. The power taken by the alternator is piffle, and anyway, doesn't it generate leccky all the time but dump it when batteries full. I think so. Either way, even a generator is only a few hp, and that'll power fridges and kettles.

Think you would be much better off on the other tack. Chuck the boat and buy a nice new one. You know it makes sense.

 

[rich]

Re: nah?

wait and sea tcm.you seem to no it all;;;

rich )