loss of power please help urgent !!! again??!!

[compie1]

referring to:

loss of power please help !!

Changed all Fuel Filters and tested yesterday but no change in speed all stays the same. filters are clean now.
What i noticed when comming back from WOT, the throttles go very difficultly back in low RPM (very hard) but still in gear. so first thing in mind is cables but at iddle (no gear) movement of cables ok and max RPM is reached.

What can it be? /forums/images/graemlins/confused.gif

 

[PCUK]

May sound too simple, but have you checked for rubbish round the prop?
Peter

 

[ians]

Van

Have a look at this site

www.boatdiesel.com

go to forum then onto CAT engines


Ian

 

[ians]

Sorry van
see you are on that already.

ian

 

[meows]

Check your air filters.
Also make sure you are still getting full travel on your throttle cables - if one has become slightly loose it will not give you full revs under power but will give it when free running.
Any extra smoke? - or a different colour?

 

[oldgit]

Sorry if covering old ground but do both engines when run WOT separately each reach (or very nearly) the same revs normally seen or does one appear to be down by a large amount.One of the engines is not doing the business,trying to find out which one is the problem.On my boat the rpm on both engines will reach 3400 when on song together ,however a single engine although struggling will still get to 3200 at WOT.My dirty filter problem was instantly solved when one of the engines kept faffing about big time when asked to do all the work alone.

 

[Jobs_a_ good_ un]

Ive Got a drop in revs on one engine spent loads trying to find out what it was and it turned out to be a fuel bug
It started after a engine service
Still not fixed to date

 

[compie1]

props and hull are clean

 

[compie1]

Airfilters cleaned and even removed
haven't tested onder load each engine WOT separate will do that first thing
havent checked cables will do that too
No xtra smoke or diff of colour in smoke

thanks for reply's

will keep you all posted,

Tom

 

[kimhollamby]

You might need to check fuel lines

As stated here prop check would be sensible.

Failing that two further things to look for:

a) air leakage on fuel lines
b) partial blockage on fuel lines

I'd go after the second of those.

When you ran the tanks low you could have picked up some much that is lodged in an elbow somewhere. However don't take the whole system apart just yet.

Try freeing off the fuel line from the upstream end of the fuel filter and then jury rig a tyre pump to the end so that you can blow back towards the tank. If there's anything in there it should dislodge it.

The engine to go for is the one pulling the lowest revs. As has been posted here the 2100rpm one will be lugging back the other engine so most likely to be the culprit.

 

[compie1]

Re: You might need to check fuel lines

Kim,

thanks for your reply, agree but how do we declare the "very hard on the throttles back from 2100 to 700 rpm under gear" ??? and if i mean "very hard" it means "leaning on them with full weight" on the other hand when out of gear throttles react normal. /forums/images/graemlins/confused.gif

doesnt seem logic does it but i gues thats boating init??!!

 

[kimhollamby]

Throttles

What kind of system is it?

Do you have to operate a latch to move between lower and upper helms or do you change between helms by going to neutral at one and picking up at the other?

 

[compie1]

Re: Throttles

Kim,

Its a open boat not a flybridge and the controls are 4 morse race controls, you know the ones with fwd/rwd on the outsides and RPM's in the middle

 

[robind]

Re: Throttles

Take boat to somewhere quiet and calm and try disconnecting the pump/throttle controll on suspect engine and with "someone else driving" try max revs (using a string on the pump lever) in a very clear area! If trouble goes, it has to be the cable or lever mech! maybe????
Rob

 

[compie1]

Re: Throttles

Rob,
Good idea will do so next sunday if weather is good enough & i'l let you know what the results are. hope its only that !!!