|
02 February 2007, 18:04
|
#1
|
Member
Country: UK - England
Town: leeds area
Boat name: nogo
Make: avon
Length: 5m +
Engine: mariner 60efi 4st 08
MMSI: 235051079
Join Date: Mar 2006
Posts: 70
|
does this sound allright ?
just replaced the middle piston and had rebored out to fit it, just got engine going now but it seems to be hunting around at idle we have used a color tune to set up the carbs and followed the manual to the letter , but i think it needs a fine tune doing to it.
please could you give me some advice as if to wether its sounding ok or whot ever as whot info i can get would be apreciated . cheers
__________________
|
|
|
02 February 2007, 23:01
|
#2
|
Member
Country: UK - England
Town: Leicester
Boat name: Vixen
Make: Ribcraft
Length: 6m +
Engine: Suzuki OB 175
MMSI: 235071839
Join Date: Jun 2004
Posts: 1,624
|
Is there water coming out of the top exhaust?
__________________
New boat is here, very happy!
Simon
www.luec.org
|
|
|
02 February 2007, 23:19
|
#3
|
RIBnet admin team
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,069
|
You're not getting enough back pressure in that drum so it's going to sound odd-specially as one cyl has now got more compression than the rest.
You're not running it under any load either.
Try it on the water.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE and HERE and support our Trade Members.
Join up as a Trade member or Supporter HERE
|
|
|
02 February 2007, 23:43
|
#4
|
Member
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,866
|
You just rebored the middle piston? Is that standard practice?
Hmm, if that's the case then you might well have some dificulty balancing the cylinders.
I would guess though that it's a combination of the lower compression and the fact that the middle carb will be out of balance as there is going to be more air fuel going into the rebored piston.
If your happy with the one cylinder rebored then the Carbs should be checked for balance.
Is that normal to have water comming out of he exhaust?
__________________
Andy
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
|
|
|
03 February 2007, 01:39
|
#5
|
RIBnet admin team
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,069
|
Quote:
Originally Posted by Hightower
You just rebored the middle piston? Is that standard practice?
|
Shouldn't be but it's a cheap 'fix' for an old engine. I used to do it on aircooled 2-stroke bikes but they went bang so often it didn't matter anyway.
Quote:
Originally Posted by Hightower
Hmm, if that's the case then you might well have some dificulty balancing the cylinders.
I would guess though that it's a combination of the lower compression and the fact that the middle carb will be out of balance as there is going to be more air fuel going into the rebored piston.
If your happy with the one cylinder rebored then the Carbs should be checked for balance.
Is that normal to have water comming out of he exhaust?
|
I wondered about the exhaust water too.
Colourtune kits are utterly useless for balancing/tuning unless you can run the engine under load to balance it. The variance is too small at the throttle openings you use with no load.
IF you can find a test wheel it might help-or cut down an old prop to make one. This is roughly what they look like but the one in the pic below is for an old Chrysler which doesn't have a through-hub exhaust.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE and HERE and support our Trade Members.
Join up as a Trade member or Supporter HERE
|
|
|
03 February 2007, 07:58
|
#6
|
Member
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,866
|
I agree. But you'll still have to balance the Carbs. Use a vaccum gauge connected to the carbs, or take it to the dealers (about a 30 min job)
__________________
Andy
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
|
|
|
03 February 2007, 08:06
|
#7
|
RIBnet admin team
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,069
|
I wonder if the carbs have take-offs for vacuum gauges?
Easy enough to drill/tap one if not I guess. Shame he's not down this way-I've got a set of gauges in the garage.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE and HERE and support our Trade Members.
Join up as a Trade member or Supporter HERE
|
|
|
03 February 2007, 15:07
|
#8
|
Member
Country: UK - England
Town: leeds area
Boat name: nogo
Make: avon
Length: 5m +
Engine: mariner 60efi 4st 08
MMSI: 235051079
Join Date: Mar 2006
Posts: 70
|
yes it kicks water out at the top dont all outboards do this its a selva, a big bag of bolts, the reason for only doing one piston is that i ordered a set of 3 in july last year and was kept waiting till november/december when selva said they dont do pistons for this engine any more so i oped for a bigger piston they had just to get the bloody thing going,still waiting for supreame marine in osset to bring prop back after 4 weeks ago ,
__________________
|
|
|
03 February 2007, 20:14
|
#9
|
Member
Country: UK - England
Town: Fareham
Length: 6m +
Join Date: Sep 2003
Posts: 7,866
|
Quote:
Originally Posted by Nos4r2
I wonder if the carbs have take-offs for vacuum gauges?
Easy enough to drill/tap one if not I guess. Shame he's not down this way-I've got a set of gauges in the garage.
|
Some vacuum gauges can be placed over the inlet opening of the carb and you simply hold it place.
Top car tuners can do it by ear. They hold a piece of tube near the opening and listen at the other end.
__________________
Andy
Looks Slow but is Fast
Member of the ebay Blue RIB cover club.
|
|
|
04 February 2007, 10:27
|
#10
|
Member
Country: UK - England
Town: leeds area
Boat name: nogo
Make: avon
Length: 5m +
Engine: mariner 60efi 4st 08
MMSI: 235051079
Join Date: Mar 2006
Posts: 70
|
your all talking about the engine kicking water out of the top exaust tube but dont some of them do it my mariner ex rnli did, also a few other makes that ive seen on the net. when we rebuilt the power head we replaced all gaskets thermostat so every thing is compleatly new so i cannot work out why its doing it , the engine was run at up to 3000 rmp for a long time yesterday and we kept a eye on the engine temp with no noticible temp diffrence its keeping the block nice and cool, just sent vid to selva to see if they know if water out of top is ok , thanks for info received keep it comming as were all beginners ,cheers andy
__________________
|
|
|
06 February 2007, 02:12
|
#11
|
RIBnet admin team
Country: UK - England
Town: The wilds of Wiltshire
Boat name: Dominator
Make: SR5.4
Length: 7m +
Engine: Yam 85
MMSI: 235055163
Join Date: Jul 2005
Posts: 13,069
|
Quote:
Originally Posted by Hightower
Some vacuum gauges can be placed over the inlet opening of the carb and you simply hold it place.
Top car tuners can do it by ear. They hold a piece of tube near the opening and listen at the other end.
|
Depends what sort of carbs you've got.
I think sending the vid to Selva was the right thing to do.
__________________
Need spares,consoles,consumables,hire,training or even a new boat?
Please click HERE and HERE and support our Trade Members.
Join up as a Trade member or Supporter HERE
|
|
|
08 February 2007, 18:05
|
#12
|
Member
Country: UK - England
Town: southampton
Make: ribcraft
Length: 7m +
Engine: 230 diesel jet
Join Date: Dec 2006
Posts: 12
|
water coming from exhaust
i have a pair of 100hp on the back they both chuck buckets full out, so i hope they should or i have double the trouble
was the piston you fitted the same wieght ? i know most oversized are matched to std or they can affect the balance
__________________
|
|
|
08 February 2007, 18:52
|
#13
|
Member
Country: UK - England
Town: leeds area
Boat name: nogo
Make: avon
Length: 5m +
Engine: mariner 60efi 4st 08
MMSI: 235051079
Join Date: Mar 2006
Posts: 70
|
yes im was told it matched the others hopefully i should get prop back from supreame tommorow so i can try under load if not theres a boat jumble on sunday near me i will pop and see if can get a spare prop,just got a email from selva and this engine does put water out of both ports, cheers andy
__________________
|
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|