Mercury 150 no tell tale

[D J Pinoy]

I have a Mercury 1988 black max xr4 150 and at idol all I get is steam coming out of the tell tale. If I Rev the engine to 2500 rpm I get some water but the stream is broken. I have already replaced the impeller and impeller housing. What should I do next?

 

[Chris1956]

The telltale on a lot of those V6 motors is controlled by the thermostats at idle. I would recommend you replace or at least test them.

 

[Faztbullet]

Test it on lake/barrel not muffs.....sound like block not fully filling.

 

[Dukedog]

on top of tha block, right behind tha flywheel you will see a 3/4" pipe plug... you can remove it, start tha motor for just a very short time ta check for water flow to that part of tha block... i have a fitting with a hose bib to keep tha water from runnin' all over tha block... this is a straight shot from tha pump... tha very first place water enters tha block... should have a pretty good volume of water there, even at idle... if not then tha pump isn't workin' as it should be..... if plenty water there move to tha t-stat housings... remove those and check for water flow.. water there, tha stats themselves may be bad.. those can be checked ina pot of water on tha stove....