Reply
 
Thread Tools Search this Thread
 
Old 02 June 2008, 07:22   #11
Member
 
Andy JC's Avatar
 
Country: UK - England
Town: Bristol
Make: Honwave T35AE
Length: 3m +
Engine: Tohatsu 18hp
Join Date: Feb 2006
Posts: 374
Quote:
Originally Posted by floater View Post
i had a same problem a couple of years ago with a 30hp yam 3 cyl 2 stroke
turned out to be crap in one of the carbs there was a piece of material bloking the throttle needle i think thats what you call it this was cleaned and it sorted it out but as you say ran fine in the tank as soon as under load no power

the way the chap who fixed mine found it was to run the engine with air intake off and squirted in some "quick start" in to the carbs to identifiy which one was faulty
Hi Andy

Sounds like a similar problem I'm currently having with with my 3 cyl Mariner('91, 50hp), took it out yesterday and had full rev range for about the first 10 mins then suddenly wouldn't rev past about 3000rpm ish(no rev counter so an educated guess) Full power did return briefly in a quick burst a couple of times but then went all together

Spoke to Nos yesterday and he said either a duff plug or crap in one of the carbs. I changed all three plugs while out on the water with no improvement so guess it might be a carb problem.

When they discovered the problem with your 30hp Yam I assume they had to remove the carbs to clean them, what sort of timescale did that take? If you remove the carbs for cleaning, do you need to re-balance them before re-fitting? Do you mind saying how much they charged to resolve the problem?
__________________

__________________
Andy JC is offline   Reply With Quote
Old 02 June 2008, 08:17   #12
Member
 
Country: UK - England
Town: Macclesfield
Boat name: Aqua Fresh
Make: Zodiac Medline
Length: 5m +
Engine: 60hp Yamaha
MMSI: 235051988
Join Date: Feb 2006
Posts: 333
I dont know how long it took the guy as i left it with him and then picked it up a week later and 100 lighter

but it was a problem that i had had for a while all be it intermitent

when the quick start was squited in to the carbs it was an immediate effect ie we were going along at about 8knots not on the plane but at WOT the engineer squirted 1 carb nothing 2 carb nothing 3rd carb whoose it was like throwing the throttle full on (which of course it was !) then as soon as the quick start had burnt up the revs dropped another spray in to carb 3 and whoose we were off again

fine after they were striped and cleaned

Andy
__________________

__________________
Stripes, we like stripes just need some stars now !
floater is offline   Reply With Quote
Old 02 June 2008, 08:45   #13
Member
 
Andy JC's Avatar
 
Country: UK - England
Town: Bristol
Make: Honwave T35AE
Length: 3m +
Engine: Tohatsu 18hp
Join Date: Feb 2006
Posts: 374
Cheers Andy
__________________
Andy JC is offline   Reply With Quote
Old 02 June 2008, 11:03   #14
RIBnet supporter
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,803
Cheers for the responses guys but I'm pretty sure my problem is electrical. The way the engine revs 'bounce' is the same as an engine behaves when it hits a limiter but obviously it's nowhere near the top of the rev range.
Jizm is offline   Reply With Quote
Old 02 June 2008, 13:45   #15
RIBnet supporter
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,803
video of the outboard symptoms below:

[YOUTUBE]<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/F6WsnWbn0XQ&hl=en"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/F6WsnWbn0XQ&hl=en" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>[/YOUTUBE]
Jizm is offline   Reply With Quote
Old 09 June 2008, 07:55   #16
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,611
I'll stick my necck out & say most intermittent nonsense is usually electrical!

I had similar probs on my 2- cyl. It was a shot spark plug - it started as an occasional hesitation, which slowly morphed into total failure over an afternoon & limping back on 1 cyl(thankfully not too far from the marina when it totally died).

I notice the problem recurrence is almost a year from when you cured it last. Try a new set of plugs again? What did you do last time that "cured" it for 10 months?

My old Suz 3-cl ran OK if a little underpowered on 2/3 cyls. My current 2- cyl behaved like a seagull on 1/2. I wonder if you are just running on 2 cyls? Try Unpluigging a spark lead and firing up. I suspect you'll find one of them off will make no diference, the other two it will barely run.
__________________
9D280 is offline   Reply With Quote
Old 11 June 2008, 02:27   #17
RIBnet supporter
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,803
~Not sure I cured it last time. The times it has happened it has been after a slow running 6 knot spell up the river. If I don't do that it doesn't occur.
Jizm is offline   Reply With Quote
Old 11 June 2008, 05:29   #18
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,611
Aha! Sounds bit like a couple of old premix yams I used a few (!) years ago at a sailing centre. Basically they oiled up after 15- 20 mins pottering about chasing toppers in no wind.....

More questions -
If it's a 2- stroke, is it autolube? If not then every so often you'll need to open it up to basically burn out the oil! The sailing centre had a 25 (2 cyl) and a 30 (3 cyl), both would oil up after about 15 mins at pottering speed. The 30 (3 cyl) was worse - it really didn't like slow running at all, but the autolube 60 on the "big searider" would run all day at idle no problem. The problem dissappeared when the engines were upgraded to the then "new" autolube type.
__________________
9D280 is offline   Reply With Quote
Old 14 June 2008, 03:19   #19
RIBnet supporter
 
Jizm's Avatar
 
Country: UK - England
Town: Southampton
Boat name: Hissing Sid
Make: Ross Smith Cobra
Length: 6m +
Engine: 200HP Optimax
MMSI: 235038046
Join Date: Jun 2002
Posts: 3,803
Quote:
Originally Posted by 9D280 View Post
Aha! Sounds bit like a couple of old premix yams I used a few (!) years ago at a sailing centre. Basically they oiled up after 15- 20 mins pottering about chasing toppers in no wind.....

More questions -
If it's a 2- stroke, is it autolube? If not then every so often you'll need to open it up to basically burn out the oil! The sailing centre had a 25 (2 cyl) and a 30 (3 cyl), both would oil up after about 15 mins at pottering speed. The 30 (3 cyl) was worse - it really didn't like slow running at all, but the autolube 60 on the "big searider" would run all day at idle no problem. The problem dissappeared when the engines were upgraded to the then "new" autolube type.
It's an autolube, and removing the plugs and cleaning them or putting in new ones did not get rid of the fault.
__________________

Jizm 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 14:05.


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