Reply
 
Thread Tools Search this Thread
 
Old 24 February 2015, 18:42   #21
Member
 
Country: UK - Scotland
Town: north ayrshire
Boat name: charlie girl
Make: reiver 3.8/regal3760
Length: 10m +
Engine: 40hp 2st 2x6lp 315
Join Date: Jul 2009
Posts: 1,495
Have you checked the choke butterfly is fully closing as suggested by davie he knows yams inside out & isn't often wrong
__________________

__________________
beamishken is offline   Reply With Quote
Old 25 February 2015, 02:44   #22
Member
 
HughN's Avatar
 
Country: UK - England
Town: Littlehampton, W Sx
Length: no boat
MMSI: 235101591
Join Date: Jan 2012
Posts: 732
Quote:
Originally Posted by beamishken View Post
Have you checked the choke butterfly is fully closing as suggested by davie he knows yams inside out & isn't often wrong
The solenoid pulls it as closed as it is possible to do by hand with the solenoid disconnected. It seems to be as closed as it is possible to go, i.e., no gaps at the sides.

I'll give it a whiff of propane and if that doesn't work give it a shot of fuel.

Its running in a dustbin. Guess where the spanner and screwdriver ended up yesterday!
__________________

__________________
"Can ye model it? For if ye can, ye understand it, and if ye canna, ye dinna!" - Lord kelvin
HughN is offline   Reply With Quote
Old 25 February 2015, 03:02   #23
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,268
RIBase
Quote:
Originally Posted by HughN View Post
The honing was pretty light and I am confident in the chap who did it: he wears a brown shop-coat with biros and a vernier caliper in the top pocket plus 'Michael Foot' glasses - old skool Engineer (with a capital 'E').
You'll be telling us next he drives an Austin Allegro Vanden Plas, complete with AA and RAC chrome badges!
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 25 February 2015, 03:23   #24
Member
 
HughN's Avatar
 
Country: UK - England
Town: Littlehampton, W Sx
Length: no boat
MMSI: 235101591
Join Date: Jan 2012
Posts: 732
Quote:
Originally Posted by spartacus View Post
You'll be telling us next he drives an Austin Allegro Vanden Plas, complete with AA and RAC chrome badges!
When I was about sixteen a friend gave a couple of us a lift home from school in a (by that time very old) Vanden Plas Allegro. Trying to impress us he took a hump-back bridge at some speed and the Hydragas suspension gave out on landing.
__________________
"Can ye model it? For if ye can, ye understand it, and if ye canna, ye dinna!" - Lord kelvin
HughN is offline   Reply With Quote
Old 25 February 2015, 04:25   #25
Member
 
RIB-Teccie's Avatar
 
Country: UK - England
Town: Leeds
Make: Valiant 450
Length: 4m +
Engine: Yamaha 55HP
Join Date: Jan 2013
Posts: 448
Thinking on. I looked at a 25 yam once, same symptoms. It seemed to prime ok, but it didn't. Turned out simply to be the bulb and connector to the engine being no standard.

If you have compression, spark and the timing is OK. It can only be the fuel pump, carb, reed or bottom seal. Only the carb and fuel pump (to a lesser extent) would affect starting.

Like I said earlier, fuel, fuel tank, bulb and fuel line have to be 100%.
__________________
RIB-Teccie is offline   Reply With Quote
Old 25 February 2015, 07:30   #26
Member
 
HughN's Avatar
 
Country: UK - England
Town: Littlehampton, W Sx
Length: no boat
MMSI: 235101591
Join Date: Jan 2012
Posts: 732
Quote:
Originally Posted by RIB-Teccie View Post
Thinking on. I looked at a 25 yam once, same symptoms. It seemed to prime ok, but it didn't. Turned out simply to be the bulb and connector to the engine being no standard.

If you have compression, spark and the timing is OK. It can only be the fuel pump, carb, reed or bottom seal. Only the carb and fuel pump (to a lesser extent) would affect starting.

Like I said earlier, fuel, fuel tank, bulb and fuel line have to be 100%.
Bottom seal as in between the block and the mid section, or between the block and the crank-case?

Thanks
Hugh
__________________
"Can ye model it? For if ye can, ye understand it, and if ye canna, ye dinna!" - Lord kelvin
HughN is offline   Reply With Quote
Old 25 February 2015, 07:32   #27
Member
 
RIB-Teccie's Avatar
 
Country: UK - England
Town: Leeds
Make: Valiant 450
Length: 4m +
Engine: Yamaha 55HP
Join Date: Jan 2013
Posts: 448
Bottom Crankshaft seal. In the housing below the bottom crank bearing.

Unlikely to cause the problems you are reporting
__________________
RIB-Teccie is offline   Reply With Quote
Old 26 February 2015, 03:30   #28
Member
 
HughN's Avatar
 
Country: UK - England
Town: Littlehampton, W Sx
Length: no boat
MMSI: 235101591
Join Date: Jan 2012
Posts: 732
A shot of fuel didn't work but continuous pumping of the primer bulb did.

Next on the agenda is the fuel pump which I can swap out this evening.
A new primer bulb arrives tomorrow.

It does make quite a noticeable ticking noise at idle and the mixture adjustment screw has very little effect (it has to go almost all the way in or almost all the way out)

It may yet be on eBay as 'spares or repairs'!
__________________
"Can ye model it? For if ye can, ye understand it, and if ye canna, ye dinna!" - Lord kelvin
HughN is offline   Reply With Quote
Old 26 February 2015, 05:57   #29
Member
 
RIB-Teccie's Avatar
 
Country: UK - England
Town: Leeds
Make: Valiant 450
Length: 4m +
Engine: Yamaha 55HP
Join Date: Jan 2013
Posts: 448
A shot of fuel should have worked. I'm surprise. Not even a cough? It does sound like it's not priming correctly and that carb you have got on does not seem right. I would strip carb and leave it overnight in a container of petrol and then blow through a the holes with an airline.

We're the reeds ok when the engine was stripped? Is the ticking a spark plug tracking between the bottom spark if cap ant the clip on the tray. That is very common if you are using the larger NGK caps or the original metal covered Yammy plastic ones. The metal can be removed with pliers and will not affect the caps. Also trim a little bit of the HT leads and ensure the caps are screwed into the lead properly.
__________________
RIB-Teccie is offline   Reply With Quote
Old 27 February 2015, 02:54   #30
Member
 
Peter_C's Avatar
 
Country: USA
Boat name: Uh...a kayak?
Length: 4m +
Join Date: Dec 2009
Posts: 1,485
Once you prime the carbs with fuel using the priming bulb the fuel pump won't do anything to help start it. In fact you could disconnect the fuel line and run off the fuel in the carbs for a few minutes. So that begs of the question of are all the carbs getting fuel properly? Is the fuel strainer plugged? Does the fuel bulb get hard as it is pumped? If not really hard it could also be a float seat that is not seating properly and causing you to flood the engine as you are attempting to prime it, even just one or two carbs flooding can cause severe issues. Do you smell fuel while cranking?

Tomorrow try starting it normally without pumping the primer bulb and see what happens.

You could try draining the fuel out of each carb and see if roughly the same amount comes out. There should be a drain screw on each carb at the bottom. Also look for contaminants and water. If one carb has more or less fuel something is wrong.

Rebuilding the carbs if they haven't been done in a long time would be a good thing to freshen all the gaskets up. The most important part is clearing all passage ways.

Once warm if it idles smoothly, is a pretty good indication of the mechanical condition.
__________________

__________________
Peter_C 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 10:31.


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