Removing T-stats and Poppet Valve

**Talon2.5** · 10-25-2002, 10:01 PM

OH!!! in the poppet cover there is a small hole that leaks water when the poppet goes bad to let you know when it does

fill that hole with a set screw to seal it

and on those covers that the two poppet holes are covered with one plate, put the tell tale hole in the rear with the 90 degree elbow it's alot easier to get to when installing the piss tube

**us1** · 10-25-2002, 10:11 PM

Bill its quite common for pieces of the impeller to come off and get caught in the passageways from the divider plate to the water jacket. I would pull both heads and the divider and look at the block.

**pirogue** · 10-26-2002, 12:00 AM

Bill,

I never had any cooling mods before, just filled cavity for pyro's and ran therm. dumps off each head.

Skip,

the small poppet is factory blocked off, and the silicone is about 3/4 of tsp so with water press. i didn't think it will go anywhere, and yes the aluminum would have been a safer route. i installed the poppet tonight but left the rubber ring in and forgot about hole in cover. i took all the guts out and bolted the 2 pieces backtogether. i will rearage tomorrow. just went buy a set of modified 5pedal reed cages from Larry D. at zuber. they replace the 7pedal. "they are bad ass"

well midnight over here so thanks again skip i appreciate it!!

Good luck tomorrow Bill.

Craig

**bill mason** · 10-27-2002, 09:20 AM

ok guys removed powerhead and what I found was a completely different design exhaust plate. I couldn't figure out why mechanic who put the 260 on and gave me the parts back had the motormounts in a sack. this exhaust plate has NO PLACE for motor mounts, no triangle shaped hole for the poppet valve to dump into. I am not a wrench by any strech but this thing looks so different I don't see how it can get water thru it and into block compared to my stock one. I was going to put my stock exhaust plate back on but looking at my B&W mag on top motor mounts it takes 2 guys to do it. I would have to remove the plate, take bolts out of yoke, put in bottom part of exhaust plate, install motormounts and shorter yoke bolts, put exhaust plate on, so I didn't feel comfortable trying to do it myself. Of course when I took it out same thing. water flying out port pee hole but very little water pressure. I don't know how water flows thru poppet valve, exhaust plate and to starboard side of block by it just isn't getting there. Didn't have any problem with the 260 so guess I will wait until it gets back. Would have liked to solve this mystery but think the offshore exhaust plate from the 260 just won't work with the 225PM. What all did I miss?

**pirogue** · 10-27-2002, 10:07 AM

i'm not familiar with 260 mid plate but, I know on 2 piece mid plate you remove upper motor mount bolts then loosen bottom motor mount bolts and the center section will tilt back to clear yoke and then remove mid plate. I have done 2piece plates myself in the past, not hard.

I'm not sure how the 260 plate is in conjunction with our 1/2 breeds so, not sure if thats your problem. I had a friend with '90 fishing motor that had hp mid plate, and it ran fine.

**MTCM** · 10-27-2002, 10:23 AM

Does your plate look like this one...............?

This is the one piece 2.5 MPP plate from a 93 260.

**bill mason** · 10-27-2002, 10:45 AM

yes I believe it does. I should have taken a picture of it but when I looked it over, compared to my stock one, it looked so much different I just thought it wouldn't work. The mechanic that put the 260 on this 225PM leg said I would need to change the exhaust plate and everything back to my original set up if I wanted to sit my 225Pm back on. I was told different by several other guys so tried to just set the new 225 PM powerhead on. The setup the 225PM came with looks just like the one in the Oct B&W mag article on changing motormounts. Do you think this plate is what is causing no water pressure? I am puzzled as hell trying to figure it out. Again there just doesn't seem to be any water getting to starboaard side of block. I even put clear tubeing on waterpressure fitting and ran it to a hand held water pressure gauge. There just isn't any water coming to the gauge and I don't think it it getting thru the holes(poppet valve now removed) in the block where the poppetvalve was. If water was getting thru the area where the poppet valve was then it would be running out the starboard side pee hole as I have a fitting coming off the poppet valve cover with a hose on it going direct to the pee hole. Thanks for posting picture, any ideas?

**MTCM** · 10-27-2002, 12:04 PM

You've got mail...............

**us1** · 10-27-2002, 12:39 PM

Post a picture like MTCM and we can tell you exactly what to do to it. If water is not flowing on one side of the block its not the exhaust plate although that is a problem too.

**MTCM** · 10-27-2002, 01:30 PM

If you can post a pic.

This thread is all mixed up. Skip is trying to help with a mod and that's OK.

Bill, you are trying to figure out a different problem.

Just trying to get the "apples" out of the "oranges".

**bill mason** · 10-27-2002, 02:42 PM

sorry guys I can't post a picture. The plate I have on now is exactly like the one mtcb posted, it is from a 1992 260. after looking at the plate difference I put new gaskets on and set the powerhead back down on it. I ran it and it was the same as before. US1 if you don't think it is the exhaust plate then what do I need to check now? I have removed the poppet valve and replaced the thermostats. mtcp I usualy post from work so I can't get your mail until tomorrow. I didn't mean to get these posts mixed up. I thought since it was suggested I do the things in this post (to correct my water pressure problem) that this would be the post to go to for help. Are you guys telling me that the one piece exhaust plate that mtcb posted a picture of will work without any modifications on my 225PM block? When you look at them the 260 doesn't have a triangle hole like the 225PM one. I don't understand the water flow and hate to take up all you guy's time. If you tell me there shouldn't be any problem with the exhaust plate I have on there now then I will need to start looking somewhere else??? Thnaks very much for your posts, wish I knew more but this is the only way I can learn this. Would love to just watch some tear one of thees thing clear down and put it back so I knew how. I am getting prety damn good at the powerhead off and on. Thanks again for your patience and help

**MTCM** · 10-27-2002, 03:03 PM

No problem with time. We here to help.

Understand you have no regular e-mail at present. Check your Private Messages here on S & F.

**bill mason** · 10-27-2002, 04:00 PM

mtcp youve got mail

**MTCM** · 10-27-2002, 04:14 PM

Got it..............

**pirogue** · 10-27-2002, 08:16 PM

Skip,

I started break-in today. Everything is running great except at 4000 25psi and 5000 peg 30psi gauge to approx 40psi, thats a short burst from 4000, didn't even stay in it for 5000 speed #'s.

How bad is that and do you think I should remove triangle plug. Right now i have quaters with 3/16 holes and dumps off each head, and the third dump is off gutless poppet valve.