Reply
 
Thread Tools Search this Thread
 
Old 14 April 2005, 04:15   #1
Member
 
benc's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Intrepid
Make: Tornado
Length: 7m +
Engine: Twin 150 Yamaha HPDI
MMSI: 235066402
Join Date: Mar 2005
Posts: 1,319
Send a message via Skype™ to benc
Twin Engines

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.
__________________

__________________
benc is offline   Reply With Quote
Old 14 April 2005, 05:01   #2
Member
 
Country: UK - England
Town: Nr Faversham, Kent
Boat name: C Rider
Make: Avon
Length: 5m +
Engine: Yam 80
Join Date: Jan 2005
Posts: 479
Quote:
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.
__________________

__________________
Searider - The Best 5.4 x Far
Swifty is offline   Reply With Quote
Old 14 April 2005, 05:08   #3
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,556
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
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Old 14 April 2005, 05:15   #4
Member
 
Country: UK - England
Town: Southampton
Boat name: SMH Rib / War Shot
Make: Ribtec / Scorpion
Length: 4m +
Engine: 10hp Yam / 150hp opt
Join Date: Sep 2003
Posts: 1,894
RIBase
Throttles

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
__________________
Searider is offline   Reply With Quote
Old 14 April 2005, 06:49   #5
Member
 
benc's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Intrepid
Make: Tornado
Length: 7m +
Engine: Twin 150 Yamaha HPDI
MMSI: 235066402
Join Date: Mar 2005
Posts: 1,319
Send a message via Skype™ to 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
__________________
benc is offline   Reply With Quote
Old 14 April 2005, 07:36   #6
Member
 
Country: UK - Wales
Town: Southampton
Boat name: DynaMoHumm/ SRV/deja
Make: Avon8.4, 5.4 & 4.777
Length: 8m +
Engine: Cat3126 Yam 90 &70
MMSI: 42
Join Date: Dec 2003
Posts: 6,556
yeah sure!
__________________
Here it comes again, I don't stand a chance
Soul possession, Got me in a trance
Pullin' me back to you - Deja Voodoo
Rogue Wave is offline   Reply With Quote
Old 14 April 2005, 18:07   #7
Member
 
benc's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Intrepid
Make: Tornado
Length: 7m +
Engine: Twin 150 Yamaha HPDI
MMSI: 235066402
Join Date: Mar 2005
Posts: 1,319
Send a message via Skype™ to 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
__________________

__________________
benc is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 22:39.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.