Been using a rather nice 90 on my 22ft yacht as some may know. Works fine and being a sailing boat I do tend to, er, sail it when poss so the motor has not had a work out and not been run beyond about 1/2 throttle. Took it out again yesterday and decided as there was little or no wind in the morning she could have a 5 hr run. So she is pushing the yacht and towing the 2.6 inflatable with beaching wheels ( and 40+ coz I forgot ) in the down position, 1/2 throttle through the moorings as usual ( gives about 3 knots ) then went to open her up to see what max was, er, well, um she wouldn't take full throttle, opening past 1/2 causes spluttering and a loss of revs ( oh and an increase in intake noise! ).
My guess is mixture, I was attempting to run it on the same 20:1 mix I use in the 40+.
As the motor is on the boat now and therefore not so easily tinkerable I am after opinions to hopefully zero in on the problem asap, so does anyone have any experience of using more oil than needed in a similar motor? would the difference from 20:1 25:1 make enough difference to see this effect? I could try raising the needle or switching mixture or should I be stripping carb ( It was well cleaned post winter lay up tho ) or changing the plug?
90 -> 45
Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo
I had my silver century on the back of my 14' catboat towing a heavy 18' motor boat and also a 12' lugger behind the motorboat, opened it up and the same thing happened, another boat took over the tow of the motorboat and could tow the lugger with full throttle, maybe you might be expecting to much out of it.
Hmm, Jeez I hope not!
When my yacht was new it was supplied with a 4hp outboard, indeed thats what was fitted when I got her, using an equation I found on the net a while ago 2.9hp should be all I NEED to reach hull speed, ( nothing in reserve obviously ) the 90 is reckoned to be around 5Hp so I was expecting more. Appreciate I was towing but ........
I was expecting that it would at least reach max revs, whether that pushed me any faster than 3 knots when towing is another matter.
Still point taken, any other comments guys? is this a classic symptom of overloading? should I just refit the M*riner
When my yacht was new it was supplied with a 4hp outboard, indeed thats what was fitted when I got her, using an equation I found on the net a while ago 2.9hp should be all I NEED to reach hull speed, ( nothing in reserve obviously ) the 90 is reckoned to be around 5Hp so I was expecting more. Appreciate I was towing but ........
I was expecting that it would at least reach max revs, whether that pushed me any faster than 3 knots when towing is another matter.
Still point taken, any other comments guys? is this a classic symptom of overloading? should I just refit the M*riner
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timberman2004
- Posts: 375
- Joined: Wed Apr 02, 2008 11:11 pm
- Location: Lerryn Cornwall
bit of crap in the fuel line perhaps ?
sounds like all is good to the point where you need a bit more juice
Every time I've encountered this, it's been fuel
don't think towing will affect the engine revs, you should be able to tie up to a mooring and the engine will rev properly ...just not go anywhere
sounds like all is good to the point where you need a bit more juice
Every time I've encountered this, it's been fuel
don't think towing will affect the engine revs, you should be able to tie up to a mooring and the engine will rev properly ...just not go anywhere
Neal...errrr... an ON, OP, 2xSD, F, 3xSJP, LLS, 2xFV, FVP, FPC, CPC WPCL, WSC, and a few eggs hatching, hopefully
95> 45
I have a model 75 that is heavily tasked, pushing a slim 33', 5000# BB 10 meter sloop. Yesterday it did the exact same thing - running rougher and only running at 1/2 throttle. Closing choke helped too. Unscrewed float bowl and there was gunk in it. Squirted carb cleaner in jets, throat, etc and put clean gas in. Problem totally solved.
This happens regularly as I have a rusty gas tank. I had put a handful of large nuts in it and put tank in a paint shaker (LOUD!) and hoped that would break rust free. Sorta worked but now I have lots of rust dust in float bowl in each tankful of fuel. I guess eventually it will be clean.
Is there supposed to be a filter in the tank outlet?
I'm sure your problem isn't thrust loading but is fuel related. Water in fuel? Dirty tank?
Good Luck,
Tom[/img]
This happens regularly as I have a rusty gas tank. I had put a handful of large nuts in it and put tank in a paint shaker (LOUD!) and hoped that would break rust free. Sorta worked but now I have lots of rust dust in float bowl in each tankful of fuel. I guess eventually it will be clean.
Is there supposed to be a filter in the tank outlet?
I'm sure your problem isn't thrust loading but is fuel related. Water in fuel? Dirty tank?
Good Luck,
Tom[/img]
Thanks for the input guys. I must admit I am aware that modern motors with high SPEED props can tend to bog down and not reach high revs, didn't think that was supposed to happen with Seagulls.
The carb should be OK but will do no harm to check again at the weekend, will try a new plug too. The tank is plastic so I don't think rust is likely
but the plastic ( ** shudder ** ) fuel tap is a bit suspect ( It weeps a little and the knob can turn a bit ) so I wouldn't be surprised if that was restricting flow. Know you cant get them anymore so guess I will have to attempt to mount a brass tap somehow, will give John a call.
Tom the thought of a tank full of bolts in a paint shaker made me laugh, your neighbours must love you!
The carb should be OK but will do no harm to check again at the weekend, will try a new plug too. The tank is plastic so I don't think rust is likely
but the plastic ( ** shudder ** ) fuel tap is a bit suspect ( It weeps a little and the knob can turn a bit ) so I wouldn't be surprised if that was restricting flow. Know you cant get them anymore so guess I will have to attempt to mount a brass tap somehow, will give John a call.Tom the thought of a tank full of bolts in a paint shaker made me laugh, your neighbours must love you!
Nuts in my tank
Oh yes, it was loud. I did it at work at the end of the day. With the right size and number of nuts and about 15 minutes in the shaker it did a pretty good job. (I run the model shops here at the US Naval Academy - wind tunnel, tank testing models - shop for Midshipmen). Despite flushing copiously in a parts washer it still contains dust which gets into my carb. I think I need to replace the missing filter that I guess was attached to the outlet?
TP
TP
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timberman2004
- Posts: 375
- Joined: Wed Apr 02, 2008 11:11 pm
- Location: Lerryn Cornwall
there is a product called red-kote fuel tank liner.
I used it on my motorbike tank which was full of pin hole rust, it was recommended by a person who does fuel tank repairs on vintage tanks.
the web site for the liner is www.ftrs.ccom.au.
I used it on my motorbike tank which was full of pin hole rust, it was recommended by a person who does fuel tank repairs on vintage tanks.
the web site for the liner is www.ftrs.ccom.au.
i put in one to many c's
www.ftrs.com.au
www.ftrs.com.au
Jeez Tom that sounds like a place to work! So many toys so little time
They do a similar tank sealer over here at Frosts ( POR15 ) http://www.frost.co.uk but there seems to be a shipping restriction on it. I plan to line a new steel tank I have with it before use so hopefully I won't get the rust probs, but yes I think you should replace the filter!!
Timberman you are probably right! adding in the bit that dribbles out when you tikkle the carb and the lot that sloshes everywhere when you tilt the motor on arrival etc. Think we could apply for reduced duty from HMRC on the basis that for every gallon we buy only half actually gets used as fuel!
Anyway, continuing with my problem, called John and have new plug and replacement ( NOT plastic ) fuel tap on the way, so guess I will be fiddling about on the mooring at the weekend trying not to drop various bits in the Crouch while doing so ( Will try and moor the dinghy under the motor )
They do a similar tank sealer over here at Frosts ( POR15 ) http://www.frost.co.uk but there seems to be a shipping restriction on it. I plan to line a new steel tank I have with it before use so hopefully I won't get the rust probs, but yes I think you should replace the filter!!
Timberman you are probably right! adding in the bit that dribbles out when you tikkle the carb and the lot that sloshes everywhere when you tilt the motor on arrival etc. Think we could apply for reduced duty from HMRC on the basis that for every gallon we buy only half actually gets used as fuel!
Anyway, continuing with my problem, called John and have new plug and replacement ( NOT plastic ) fuel tap on the way, so guess I will be fiddling about on the mooring at the weekend trying not to drop various bits in the Crouch while doing so ( Will try and moor the dinghy under the motor )
I used por15 originally in the tank but it failed, found out from the tank repairer that mine was the 3rd bike tank that he had to remove the por15 in the last few months, in defense of the product I couldn't follow the directions because of the nature of the tank I could not drain it properly. He had to burn the liner out and put a drain plug in the tank, the red-kote liner was easy to apply and if you don't use it all you can store it in the container sealed properly for future use. The por15 you have to throw the excess away. The seagull would work well with the por15 as you can drain it easily but the red-kote would be better as you don't have to throw the excess away.I think the best idea though is not to use the steel seagull tank and get the long range bronze tank instead.
Oh dear! well its gone from a 90, to a 45 and now to a zero!!
Got to the boat Saturday armed with new plug and a metal fuel tap and the said 90 wouldn't start at all! Fitted new plug, nothing. tried changing plug gap ( unsure if I have mk 3 or mk 4 ignition at the moment, its a 1988 model but I haven't seen the flywheel yet ) still nothing. There was petrol in the carb ok so I took carb off, stripped cleaned etc. and changed the tap. No crud in either filter but there was something in the float bowl, looked like the tiny metallic bit in silver paint, not sure where that came from, can only assume the carb itself ( plastic tank ) Finally got round to checking spark and it looks like I have run out of them ( although it was hard to check as it just started raining at this point )
Bit odd that it seems to be just getting worse with time! I am thinking ( hoping?! ) HT lead now but will have to swap the motor for a backup of some description ( M*riner I guess if I can get that running again ) then check the ignition of the 90 at home where I can work in relative peace.
Will post what I find for the archives.
Got to the boat Saturday armed with new plug and a metal fuel tap and the said 90 wouldn't start at all! Fitted new plug, nothing. tried changing plug gap ( unsure if I have mk 3 or mk 4 ignition at the moment, its a 1988 model but I haven't seen the flywheel yet ) still nothing. There was petrol in the carb ok so I took carb off, stripped cleaned etc. and changed the tap. No crud in either filter but there was something in the float bowl, looked like the tiny metallic bit in silver paint, not sure where that came from, can only assume the carb itself ( plastic tank ) Finally got round to checking spark and it looks like I have run out of them ( although it was hard to check as it just started raining at this point )
Bit odd that it seems to be just getting worse with time! I am thinking ( hoping?! ) HT lead now but will have to swap the motor for a backup of some description ( M*riner I guess if I can get that running again ) then check the ignition of the 90 at home where I can work in relative peace.
Will post what I find for the archives.