Go Back   RIBnet Forums > RIB talk > Engines & props
Click Here to Login

Reply
 
Thread Tools Search this Thread
 
Old 04 May 2015, 08:41   #21
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Highland Bluewater
Length: 6m +
Join Date: Mar 2013
Posts: 1,647
It looks like the priming bulb's collapsed on the video, your tank's not venting.
__________________
Last Tango is offline   Reply With Quote
Old 04 May 2015, 09:57   #22
Member
 
Country: UK - England
Town: Cambridgeshire
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Yam 15 Tohatsu 9.8
Join Date: Nov 2007
Posts: 8,305
Kestrel something I notice is that you appear to be operating the fast idle knob every time you speed up/slow down from idle to max?? Once the engine is warm it should idle fine at the slow (fully anti-clockwise) setting... the fast position is only for keeping the engine from stalling when cold but you seem to be turning it to "fast" when you are going to go fast??
__________________
Fenlander is online now   Reply With Quote
Old 04 May 2015, 13:52   #23
Member
 
Country: USA
Town: New Jersey
Make: 733
Length: 7m +
Engine: Yanmar
Join Date: Jun 2010
Posts: 234
Yea, don't touch that fast idle knob while running the motor. It pushes down a valve/button under the cowl, leave it counter clockwise (disengaged) all the time.

Sounds like your tach is off to me as well. That's not 7k. And if you were revving to 7k it would blow up in short order...

Dying on idle sounds like your low speed jet on the carb.

I'd do all normal maintenance like: fully clean your carb, new plugs, lower unit fluid, put that Tstat in, compression test.


Motor sounds healthy to me, video looks like boat is performing like it should.

getting these small boats on plane is like an on/off switch. The bow will raise up like that, then once you hit a certain speed and also shift your weight as far forward as possible, it'll plane and accelerate fast.
__________________
95gstnj is offline   Reply With Quote
Old 04 May 2015, 14:05   #24
Member
 
Country: USA
Town: Chicago
Make: N/A
Length: no boat
Engine: N/A
Join Date: Jan 2015
Posts: 75
Quote:
Originally Posted by 95gstnj View Post
Yea, don't touch that fast idle knob while running the motor. It pushes down a valve/button under the cowl, leave it counter clockwise (disengaged) all the time.

Sounds like your tach is off to me as well. That's not 7k. And if you were revving to 7k it would blow up in short order...

Dying on idle sounds like your low speed jet on the carb.

I'd do all normal maintenance like: fully clean your carb, new plugs, lower unit fluid, put that Tstat in, compression test.


Motor sounds healthy to me, video looks like boat is performing like it should.

getting these small boats on plane is like an on/off switch. The bow will raise up like that, then once you hit a certain speed and also shift your weight as far forward as possible, it'll plane and accelerate fast.
I had tried running the idle slower, but the motor was much more prone to cutting out. It had been running for a bit before i tried doing so, too.

I'll bring my tach with to the shop, maybe they'll know what's wrong. All of that regular maintenance stuff was just done too, actually.
__________________
kestrel452 is offline   Reply With Quote
Old 04 May 2015, 15:31   #25
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
On your speed thing, it's pretty normal for a boat to run at low speed off plane, a higher speed on plane, and almost nothing between those two. My SIB would plow up to about 12 MPH, then jump to close to 20. Between that, it was either coming up onto plane, or falling off.

I agree that's not 7K rpm. It also doesn't sound like half that though, which is what I would have expected with a mis-matched tach setting. Does your shop have access to water? If so, have them hop in and run it. If not, ask a tech to go for a ride with you. Nothing like a hands on experience over a verbal description.

For your trial period; try and get as much weight forward as possible; that will help alleviate the nose-up tendency during the hole shot. Once you get the thing working, you can adjust balance.

As Pikey said, there's a lot of things that *could* be wrong. Most likely it's just a couple, but you never know until you've solved them.

Luck;

jky
__________________
jyasaki is offline   Reply With Quote
Old 04 May 2015, 17:57   #26
Member
 
Country: USA
Town: S. Carolina
Boat name: D560
Make: Avon
Length: 5m +
Engine: 2016 Merc 115hp CT
Join Date: Aug 2013
Posts: 1,277
I would suggest moving the fuel tank to the bow.

Also, if it is an Attwood tank, they sometimes have issues...A quick way to diagnose : Run the engine with the cap unscrewed most of the way. If this fixes it, contact Attwood for a new cap.
__________________
Richard
Gluing geek since 2007
Opinions and intepretations expressed are solely my own and do not express the views or opinions of my employer
office888 is offline   Reply With Quote
Old 13 May 2015, 00:27   #27
Member
 
Country: USA
Town: Chicago
Make: N/A
Length: no boat
Engine: N/A
Join Date: Jan 2015
Posts: 75
Just got everything back from the shop, they claimed it was a bad engine side fuel line connector. They took my Attwood line, and replaced everything forward of the bulb. Mercury fuel line and a Mercury OEM fitting are now in the engine side half of it. I have to say, it was a huge pain trying to get that original engine connector hooked up, really had to force it. This new fitting just slips and clicks right on like a glove. I don't know why the Attwood "Mercury" fitting sucked so much, but I'll never buy Attwood fuel lines again. The other shops that inspected my motor never had the tank and line before, but the first thing they said when I brought it in was "that's a Johnson connector on your fuel tank...". Little did I know after another shop yet again saying the engine itself was perfect, that the FUEL LINE was the problem. The shop is sure of themselves that the connectors on my tank and line are Johnson, though I think they're just crappy versions of Mercury fittings. Everything I bought is what Attwood calls Mercury compatible.

Entire Fuel Line Kit + Box....
http://i.imgur.com/TWa5bP1.jpg

"Real" Mercury engine side connector (left) and original Attwood "Mercury" fitting (right)
http://i.imgur.com/svKTNIP.jpg

Tank side connector (still original Attwood)
http://i.imgur.com/npuL7Sj.jpg

Tank outlet fitting...
http://i.imgur.com/QL4Y00n.jpg

I bought two brands of tank fittings, one Moeller and one Attwood. They look slightly different, but both fit in the tank side connector on the line. Not sure why the tank side stuff works but not the engine side. I don't know what to think anymore, at least the tank side connectors aren't failing me. Maybe next year I'll replace everything fuel related with Quicksliver/Mercury OEM gear.

Moeller (left) vs Attwood tank fittings
http://i.imgur.com/C7IEZkP.jpg

They also claim my tach was accurate to within 50-100rpm of their readings, though that my point of measurement may not be as accurate since I'm getting it off the rectifier and they're getting it off the spark plug which may have been causing the inaccuracy at speed. It was a weird and contradictory answer, but I just might have to accept the fact I can't trust the current tach setup I have.
__________________
kestrel452 is offline   Reply With Quote
Old 13 May 2015, 07:13   #28
Member
 
Country: UK - England
Town: Leicester
Length: 5m +
Engine: 135hp Mercury
Join Date: Sep 2013
Posts: 1,409
Have you had it out & has it solved the running problem?

As an aside 'pattern parts' i.e. non-genuine are frequently a source of problems with cars - personal experience with some - so it may be that the same holds true here.
__________________
paintman is offline   Reply With Quote
Old 13 May 2015, 08:36   #29
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Highland Bluewater
Length: 6m +
Join Date: Mar 2013
Posts: 1,647
Your tacho is set-up to work off the rectifier feed. It's configuration is based on the number of phases your charging system uses and has no relation to the ignition/number of cylinders etc. You could try some of the other settings on the tacho to see if you get more realistic readings but getting part numbers of the charge stator assembly to identify it would involve pulling the flywheel and isn't worth it.......if it ain't broke, don't fix it
__________________
Last Tango is offline   Reply With Quote
Old 13 May 2015, 08:39   #30
Member
 
Country: UK - England
Town: Manchester
Boat name: Serenity,PuddleHound
Make: Avon R310,Prowave380
Length: 3m +
Engine: Johnson10,Mariner10
Join Date: Oct 2014
Posts: 209
Surely a tinytach would suffice?
__________________
blootac is offline   Reply With Quote
Old 13 May 2015, 08:46   #31
Member
 
Last Tango's Avatar
 
Country: UK - Scotland
Town: Denny
Boat name: Highland Bluewater
Length: 6m +
Join Date: Mar 2013
Posts: 1,647
Quote:
Originally Posted by blootac View Post
Surely a tinytach would suffice?
I'd have though that's a fair solution. Probably not weatherproof but once you've established rev range is ok, you don't really need it anymore.
__________________
Last Tango is offline   Reply With Quote
Old 13 May 2015, 09:06   #32
Member
 
Country: UK - England
Town: Manchester
Boat name: Serenity,PuddleHound
Make: Avon R310,Prowave380
Length: 3m +
Engine: Johnson10,Mariner10
Join Date: Oct 2014
Posts: 209
Easy enough to weatherproof it.
Mine turned up yesterday (albeit a £6 version from Hong Kong). Going to run epoxy around the edges of the screen and the back, as it's meant to be sealed for life anyway, and stuff some silicone sealant around where the sensing wire comes out the housing.

Plus in the above case it's only got to work for a few hours
__________________
blootac is offline   Reply With Quote
Old 13 May 2015, 15:01   #33
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by kestrel452 View Post
I don't know why the Attwood "Mercury" fitting sucked so much, but I'll never buy Attwood fuel lines again.
Well, add Perko to the list of brands to stay away from. I replaced the fuel line on my Honda 40, and the Perko bulb wouldn't even pump air, much less fuel. Had to trash the engine connector also, as it wouldn't depress the quick release check ball enough for fuel to flow.

Moeller seemed to work better (meaning it actually worked.)

Hope it works better;

jky
__________________
jyasaki is offline   Reply With Quote
Old 13 May 2015, 16:05   #34
Member
 
Country: USA
Town: S. Carolina
Boat name: D560
Make: Avon
Length: 5m +
Engine: 2016 Merc 115hp CT
Join Date: Aug 2013
Posts: 1,277
I utilize Attwood Sprayless fittings and an Attwood fuel tank, but my fuel hose is Gates, and I utilize a Parker-Racor 490R-RAC-01 fuel/water separator which has a primer button on it.
__________________
Richard
Gluing geek since 2007
Opinions and intepretations expressed are solely my own and do not express the views or opinions of my employer
office888 is offline   Reply With Quote
Old 14 May 2015, 20:16   #35
Member
 
Country: USA
Town: Chicago
Make: N/A
Length: no boat
Engine: N/A
Join Date: Jan 2015
Posts: 75
Tank tested the engine myself with the new fuel line. I think it's working okay now :-)



Does anyone see the engine or tachometer doing something strange in the video that I might not have caught?
__________________
kestrel452 is offline   Reply With Quote
Reply


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




All times are GMT. The time now is 23:43.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.