yamaha malta stalling!! help:(

W

will.s

New Member
Joined
2 Aug 2011
Messages
8
Visit site
hi there
as it says in title having trouble with my yamaha malta, idles okay/pulsing but as soon as i try any throttle it stalls, what could this be? i think its getting to much fuel but is this possible? all i hear of is people not getting enough fuel?

many thanks
will
 
will.s said:
hi there
as it says in title having trouble with my yamaha malta, idles okay/pulsing but as soon as i try any throttle it stalls, what could this be? i think its getting to much fuel but is this possible? all i hear of is people not getting enough fuel?

many thanks
will
Click to expand...

If its pulsing (hunting?) then it sounds as if it is short of fuel.
 
You dont give any model details such as HP and year.

But I assume it has an internal fuel tank ?

Check the tank vent, check that there is a good flow of fuel to the carb.
Clean any filter in the tank outlet or in line.
A partial blockage in the fuel supply might explain the pulsing ???

Does it help if you choke it . If so it probably needs a carb clean.

If there is any sign of the carb flooding then the float and needle valve require attention. Unlikely if it idles.

If it has a remote tank does pumping the bulb help

Have you tried a new plug(s)

If new plugs dont sort it and you cannot find any problem with the fuel flow then a carb clean is probably on the cards.
 
Sorry I'm not sure of the year, but I believe the Malta is 3bhp.
I have cleaned all fuel lines/system and fault still present, I have cleaned the carb and still problem! I slightly boiled the carb for 30 mins today but have not tested yet, is it possible to be overfueling?
 
I slightly boiled the carb for 30 mins today
Click to expand...

Boiled it ?

But have you stripped it down and cleaned the jets.

I think if it was flooding it would be obvious if you took the air silencer off.
It would probably not idle either
 
Yeah I read somewhere that if you boil it all the small passage ways clear? I took the air silencer of and got a view of the jet while running and there just seems to be ALOT of fuel sqirting up when j put the throttle on. I'm guessing the electrics are fine due to it idling okay?
 
take the recoil off the top and try spinning the flywheel by hand with the plug out.

the exhaust baffle which also holds the shaft and bearing corrodes and swells onto the driveshaft, it could be that your starting it ok but it loads up with friction as soon as the throttle increases, by turning by hand you should be able to feel if its stiff to turn.

steve
 
davidej said:
Are you sure it doesn't have one of those orrible little filters hidden in the petrol on/off tap?
This caused me months of grief with my malta.
Click to expand...

+1 and years of grief

Edit bit - The jet on mine looked clear but had a slight blockage that mucked up the running. It does not take much to alter the fuel flow through the jet. Just need to sort out the electrical problem on my spare malta now.
 
Last edited:
Sounds like water in the float bowl.

Empty the tank. Take off the carb and clean it out.

Don't rely on the drain screw on the float bowl because it goes the 'wrong' way on the Malta. (It's 90 degrees wrong, in the useful sense - it'll only drain if you if you rotate the engine to handle downwards or more).

They are a lovely engine, but very picky about fuel cleanliness.

If it ain't that, I'd be looking at the suppressing capacitor and coil.
 
Have you tried opening the throttle and pulling the choke on at the same time. If it revs up without stalling, then your main jet is blocked.
The best way to clean the carb and jets is with a high pressure airline and a trigger gun.
Don't forget there may be an emulsion tube behind the main jet which will need cleaning as well.
Not sure on that carb, but it's worth checking.

Spewing fuel could indicate a jammed needle valve in the float chamber, but that doesn't fit with stalling when you open the throttle.
 
Last edited:
Yeah I read somewhere that if you boil it all the small passage ways clear?
Click to expand...
"Jamie Oliver Book of Outboard Maintenance" ? :D

Strip it down and clean al the jets and passages. Use soft copper wire to clean all the jets and an air line if available to blow through all the passages after soaking in carb cleaner.
 
Carb all cleaned and problem persist! I noticed today that when it stalls some exhaust fumes exit through the carb... Is that normal? Thanks for everyone's advice :D
 
Without applying any detail thought to it perhaps the ignition timing is wrong. If it over-advances when opening the throttle some exhaust gas may escape the inlet port and the fuel burn may occur too early, effectively slowing or stopping the piston.
(in general terms)
 
could there be compression problems? say if the piston ring are shot?
i have spare ones but dont know what one is the top/bottom ring :/
 
could there be compression problems? say if the piston ring are shot?
Click to expand...
If it starts without great difficulty then poor compression is unlikely to be the cause.

Have you tried a new plug ?
 
Last edited:
You must log in or register to reply here.

Share this page

Top