150HPDI won't flush on muffs

[Jon Tallis]

I hope someone can offer some advice here. My 150HPDI had become allergic to flush muffs! Flushes fine if a drop it in a tank but just won't create a water tell-tale when I put it on muffs.
Impeller is new and the muffs are a good quality "double entry" type with rectangular cups.
Any ideas?

[jwalker]

Have you pulled the muffs apart to check for blockage? Water supply pressure or flow limited? Hose restricted?

[neil.mccrirrick]

Water pressure. Tbh I have a 225 opti and it’s never flushed on muffs but is fine in a tank. Just not enough water

[Pipster100]

Hi,
My Yam150 4S doesn't flush on muffs either, works perfectly in a tank. I got hold of an old 100l IBC and cut the top out, now just reverse up each time I recover and flush the engine.

[Wightdiver]

Originally Posted by Jon Tallis

I hope someone can offer some advice here. My 150HPDI had become allergic to flush muffs! Flushes fine if a drop it in a tank but just won't create a water tell-tale when I put it on muffs.
Impeller is new and the muffs are a good quality "double entry" type with rectangular cups.
Any ideas?

I too have a 150 HPDI, which struggles to flush on muffs. In the water its perfect but on muffs it can take 10 -20 seconds before water runs from the tell and then its never as strong.

[Limecc]

On my DF50 the official instruction is to place a piece of gaffer tape (!) over the intake under the anti ventilation plate when running on muffs. This must raise the water level in the leg.

[Matt]

Yeah, muffs can be a tricky call. On my motor with muffs with good flow and all the hose water going through the system, there’s not enough flow to keep it cool at idle - sooner or later the flush water boils in the exhausts and all I get out is steam. So just do the best I can.

[69cmw]

My Yam Pro V 200 pisses out the tell tale on the muffs

[Pikey Dave]

Muffs are tricky [emoji848] I’ve had engines that are happy running on muffs, others just don’t want to know. My 140 Suzuki is happy on muffs, I’ve just done some work on a 50hp Suzuki & it was hit & miss. A cut down wheelie bin to the level above the impeller did the trick.

[Jon Tallis]

Thanks for the info everyone. Water pressure is good, hose and muffs are new.
Looks like I need to sort a tank - quieter for the neighbours too when I come home late!

[Chanchan168]

My hpdi never runs on muffs. These Motor’s need a head of water before you’ll get a tell tale. Need a tank full of water up to cavitation plate before you get a spout.

Just the way they are

[jwalker]

My 150 hpdi's do flow out the tell-tail on muffs but it's a bit weak. However, they didn't before I cleared out the wee rubber tube from the engine to the nozzle - seemed ok on the ocean but not the muffs. Worth a check, easy to do.

[Limecc]

Originally Posted by Pikey Dave

I’ve just done some work on a 50hp Suzuki & it was hit & miss. A cut down wheelie bin to the level above the impeller did the trick.

Obviously pre 'A' model and used no gaffer tape then.