Wspcl stutters and dies mid throttle

[bay_cloud]

Hey all, i have a saltwater seagull. Starts up decently well, but unless i give it 2/3rds to full blast without choke it dies. It can do a slow idle fine.

Is this anything other than a carb clean or adjustment? Can fuel mixture cause this?

[seagull101]

It will more than likely be a fuel problem, is it a amal 416 or a amal 2 jet?
For the 2 jet:
Remove the banjo bolt on the bottom of the carb and clean the filter thats inside the bolt, you may as well dismantle and clean the whole fuel system while you are at it!

For the 416:
Unscrew the screw that holds on the fuel line, remove the filter and clean, you also probably should clean the whole fuel system as well.
Also for the 416 you should unscrew the float bowl and clean.

Check and double check that you can clearly see daylight looking through the jets in your carb, just one on the 416 and 2 jets on the 2 jet/46n, hence the name 2 jet!

For the mixture on the 2 jet:
Size 45 jet is 10:1
Size 40 or no number is 25:1

For the mixture on the 416:
Size 95 is 25:1
Size 100 is 10:1

Hope this helps you.

Jacob

[Charles uk]

Jacob there is no 10:1 jet for the 416, If you read the owners manual the 100 jet was used in a 418 on a Curlew!

It wouldn't hurt to check the filter is clean on the fuel tap.

[bay_cloud]

Ok, probably time to pull it from the boat. It's the 10 to 1 carb.

[red42hj]

Hi Bay Cloud, did you solve the problem? Idling ok but erratic open throttle sounds like the jets.

[bay_cloud]

Sorry for the lack of followup. Finally got a chance to totally clean the carb. Don't have carb needle tools though so while i have an Amal carb, i dont know if a previous owner changed needles. It does have an autolite d9 equivalent spark plug...will test a d21 tomorrow which is my spare.

It runs about the same, and better on a super low oil mix (25 to 1). Sure doesnt seem to have any leaks, everything is tightened down well amd hose looks in very good condition.

[bay_cloud]

Plug pic

[Adrian Dale]

Looks to me like you are running too rich, perhaps at 25 to 1 without the correct needle. If you want to run at 25-1 get the correct needle from John otherwise run with a correct mix of 8 to 1 which will give correct fuel to air ratio in the combustion chamber. The wet on the plug is not oil, but unatomised fuel. Then give her a good hard run she will thank you for it. I never change the design fuel mix on any of my engines. if you are into racing you will want to try a richer mix, but if not stick with BS recommendations. The fuel to air mass ratio will be correct resulting in good atomisation, the correct air fuel mass ratio is critical best regards, for xmas AJ

[Charles uk]

Bay-cloud after giving your carb a real good spring clean, why not take it into Sean (415-861-6124), he must be only be up the road from you, he will be able to tell you which jets your carb has & what fuel mix it's setup for.

A very nice man, I met him the year his son was born, give him my regards, he knows his stuff, he's local & can supply you with a new spark plug.

[Adrian Dale]

sage advice Charles

[bay_cloud]

Alright so I was able to figure it out! Apparently a deep skinny 5.5 mm socket will undo the jets. So I have a 25 and a 45 I believe (amal 2 jet). I tried running it on 10 to 1 and what I noticed was that it needs choke for sure to start, and then when I take the choke off it starts to die. However if I increase the throttle then it easily catches on again. So basically idling with and without choke requires two different throttle settings.

The needles and everything else appears to be in good condition anyway. Am going to test it tomorrow

[bay_cloud]

Ok well after actually taking it out on the water the update is that it runs great at idle with choke all day. But when I take the choke off and give it any kind of throttle it sneezes almost immediately after rising in revs. It will keep puffing popping or sneezing until it dies without choke.

[Charles uk]

It doesn't sound like you cleaned it very well, somewhere you've got a fuel restriction, clean everything right back to the fuel in the fuel tank!

[bay_cloud]

Aaaand the last update is that my champion d21 spark plug is either the wrong type or broken. The autolite 373 ran almost totally fine (still finicky going from choke to no choke - i have to get in gear with choke). Almost there!