Twin Engines

[benc]

Right,

I have a problem with one of my engines....

I have noticed it before... but put it down to me using one engine mainly when I am going down the rivers, no point using two engines when im doing 6 knots...

However, since I fuelled up I made sure that I use both engines to do 6 knots... and I have noticed that one engine uses more fuel than the other. After coming back last night one tank was on half and the other on quarter.

Now - I think I know the cause... but not sure how to sort it... I was looking at the rpm last night, and the engine using more fuel runs a few thousand rpm higher when both throttles are in the same place... so I guess I need to adjust the throttle cable so that it moves both engines at same speed...

I guess this could also account for part of the reason I was chinewalking 40knots or so.

What I need to know is how I go about adjusting it?

On a slightly different note, what RPM should I be getting at WOT?

Thanks in advance.

[Swifty]

Originally Posted by benc

What I need to know is how I go about adjusting it?

I am assuming you don't have the workshop manual to hand, so just do it by eye.

1. Put the engine into gear and check both throttles start in the same place.
2. Advance one throttle until the revs start to pick up.
3. Advance the other throttle until this engines revs pick up.
4. If there is a difference in throttle positions then move the cable adjuster on each engine so they both pick up revs at the same position.
5. If they still dont 'track' together. This will have to be sorted with a workshop manual as its the carb/EMU sensor relationship that needs adjusting.

Hope this helps.

Tim'mers.

[Rogue Wave]

were the engines serviced before or after you bought the boat! if not you should do that anyway and get em to sort the throttle linkage out at the time!

until you have the linkage sorted out the just adjust the throttle position acordingly. Next time youare in the Itchen (and you seem to always be there or there abouts) call in to the yard and we will show you how to sort the linkage out and how to maintain you engines and give you some advice . it's a simple but fiddly task to do if memeory serves me right

Chinewalking, if the boat was pulling to one side always then it might well be the reason. does the boat fly straight or does she twist in Mid air

[Searider]

Ben,

Throttles rarely line up exactly. If they are only a little bit out then don't worry too much - just set the throttles so that the RPMs are the same. With a bit of practice you will be able to do this by ear more accurately than with the tachos alone.

If they are an inch or so out then cable adjustment is definately required. Do the engines both make the same RPM at full throttle?

Duncan

[benc]

The engines were supposedly serviced as part of the deal when we bought the boat.

Swifty - Thanks for the advice I will have a look and see if I can do it, if not I think I will have to take up Stuart on his offer

Rogue - maybe ill come up tonight if you are around?

I will be going down in 10 mins to fuel up, so if you are up for it, maybe we can go for a spin tonight?

Thanks guys.

Ben

[Rogue Wave]

yeah sure!

[benc]

Thanks for getting this sorted for me!

I actualyl get more performance out of the boat again - but back to chine walking

Before 40 knots was about all I could get, but tonight... I was getting 41.7 knots at about 85-90% throttle - im sure I can push it a bit harder... but need to find out what causing it to chinewalk first