New Here - Bullet 1750 Issues

[widge]

Hi All,

Im new here another Bullet 1750 owner from Aus.

I recently purchased this boat, and noticed off idle holeshot the boat would stumble then take off, i have had a mechanic rebuild the cards for me which made it better but its still not right.

I did notice over the weekend, if i give the boat a rev, then put it in gear it holeshots great, same if i come to a stop from cruising speeds, then holeshot again its fine.

When im taking up the rope for waterskiing or the likes, when i go to take off it stumbles again.

I think its rich at idle causing the issue? Thoughts?

Sorry engine is a 1989 Merc 2.4 200hp

[Ira Tindale]

Yea it sounds rich. Check ur idle circuit jet size. They should be around .046. Go bigger to lean down the idle. I install .056 in those engines and it works well. Just my .02 cents.

[widge]

do you have a pic of where the idle jets are?

I found a manual Top Right of the card is the idle jets correct?

Where do i purchase jets for these carbs?

[widge]

Ok i know where the idle ai jets go, top right of each carb, i will check tonight whats in them currently,

Where do i purchase the different jets?

[gmjim]

Where in Aus are you? Kev at Qld outboard wreckers has jets. Or just go to your local merc dealer.
i can give you the part no if you tell me what size you want...
what is your idle speed in the water, in gear and out of gear??
is the motor stock?

[widge]

Thanks for your reply,

im in NSW, im after the .056 Idle Air Jets as suggested, ill give them a try

As far as i know the engine is stock, i not long ago brought the boat.

Idle speed in gear in water is around 800rpm, out of gear around 1000rpm

[widge]

Actually looking at other pics, my engine doesnt have the filter cover on the front with the side pipe things coming out

It has velocity stacks instead and no filters

[widge]

Ok so i have taken a look

Its running WH-22 Carbs

I removed the trumpets to get to the triangle where there is supposed to be jets and there is no jets just threaded holes??

Has anyone got any ideas? the trumpets cover half the the triangle should i test with not trumpets?

[tony1204au]

The threaded holes in the front of the carbs are where the vent jets were... We always remove these... The idle jets are on the sides of the carbs, behind a brass hex screw... Idle jets at the top, mains on the bowl...

[widge]

Thanks for your reply,

Ok so i need to remove the idle fuel jets from behind the hex screw and make these smaller to restrict the amount of fuel flow correct?

[tony1204au]

I would first get everything else right before playing with jets...
start with a compression test, proper spark test, do a proper link / sync, make sure carbs arent flooding, and fuel pump isnt leaking into crankcase. Make sure carbs have the original idle jets in them... If at this point, it still stumbles, then i would play with the jetting...

[widge]

I took it to my marine bloke to fix, he said thats about as good as it gets

He did a lync and sync
Checked Spark
Compression 130 on all 6
and he did an overall check over and said everything is fine

I had him clean the carbys after he did all of the above it was heaps better but still not right!!

[tony1204au]

Thats a good start i suppose... Are you sure your "marine bloke" is competent??
Id be doubtful if he says everything is fine, yet the motor still stumbles...
pull your idle jets out, tell me what size they are, and ill advise from there...
do you know if the carbs are the originals? Maybe even post a serial number off the powerhead and ill look up to see what you have exactly...

[widge]

Many years ago my old man had a bullet and this particular marine shop looked after it, but i think the mechanic has changed since then......

It will only stumble if its idling for a little bit say 10 seconds of idle it will stumble on full throttle

If i stop and full throttle straight away its fine.

Is there only one jet behind the Hex screw? on each side?

[tony1204au]

There is a total of 6 idle jets. One each side of each carb... All behind those brass hex screws..