260 thermowashers

[chad202]

Is it okay to run 1/4" washers instead of 1/8" washers. If so, is it okay to have a hose routed off each side going out the cowl. Having problems with 1/8" washer getting plugged with duckseed and would like to see a flow off each side. With the starboard connecting to the port and then the port going out the back, your starboard could plug but not no it. I've plugged of the big dumps in the exhaust plate and drilled 19/64 holes instead. I also have a needle valve in the side dump to control water pressure but to mainly make water come out the top of the heads when idling. Head temp was getting up there until I done these mods. Are these wrong.

[THE FAST ONE]

Hey Chad,i Run Washer's Instead Of Thermostats,pluged Top Of Block,pluged Popit Valve Outlet,plugged Hose Dump To Mid Under Cowl Skirt,two Hose's Off Each Head,this Is A Fishing Mota 99 Promax,two Year's So Far No Problems,run's A Lot Cooler Idling & Wot,heard They Would Cold Seize That Way By Many,so Far So Good,thought It Always Ran Too Hot,when High Idling Very Long.--thanks Ed:) DON'T SEE WHY 260 WOULDN'T BE OK,GO FOR IT,MY .O2.

[us1]

Running 1/4 instead of 1/8 washers will lower your water pressure and run the block way cooler. Worse than that it will cause the heads to run much much hotter. Not really a good combination. What happens is you have two small 19/64 dumps in the exhaust plate and two large washers in the heads, all the water leaves the block without going through the heads first through the ¼ washers. Duel hoses make the problem even worse. You can run duel hoses with 1/8 washers without a problem. The 1/8 washer will control the flow.

[chad202]

Now I'm really confused cause my head temp came down after doing it like this.

[THE FAST ONE]

:) :)
Now I'm really confused cause my head temp came down after doing it like this. I DIDN'T MEAN TOO CONFUSE ANYONE,BUT I WOULD PUT A LOT OF VALUE,IN JOHNS EXPERENCE. MAYBE MOTA'S GETTING TOO MUCH DUCKSEED IN IT.---ED

[us1]

Where is your head temp sensor located and what is the temperature its giving you?

[chad202]

John, here the sequence of events. Swapped my 225 promax powerhead for a 260. Also swaped the exhaust plate, tuner and water tube. My first trip out, I noticed that is was only pissing from the poppit dump at idle.(no poppit valve). Once on plane, it would piss from both sides. I started researching this on this site and one of the things I found mentioned was the dump holes were all over the place on the 1-piece plates. In a post, I think by you, you mention plugging these off and drilling 19/64 holes. Well, I did that cause I found my motor was running a little warm and thought it was going out the dump. Well, this did bring temp down a little.(measureing head temp between 2&4) but still no water flowing from the top of the heads at idle and the temp would climb. So, I installed a needle valve in the poppit dump hose and pinched it back a little. This forced water out the top of the heads. I may be idling for long times, that's why I think water should come out at idle. Well all was good, temp fine, flowing from all three hose at idle, then I ran into the propblem with duck seed plugging the 1/8" washers. I drilled 1/4" holes in two quarters and took the 1/8" washers out. Well, I didn't have the plugging problem again and the head temp ran ever a little cooler. Around 135ish. Am I wrong for wanting to see water coming from the top of the heads at idle. If not, is the block full of water?. I'll call you if you like, what a good time.

[david laser86]

Chad, Did you swap to the 3/4 water tube? I've had oveheating problems at idle with the big tube on 20" motors. Just a thought.....
Will you be riding tomorrow?
Dave.

[chad202]

Yes, I did swap to the 3/4" tube. Yes I will be riding but not driving. Still waiting on ECU so I'll be tagging a ride. I could've gotten one today but Roberie can't take me to finish up so it'll be next week. :(

[us1]

Where is your head temp sensor located and what is the temperature its giving you?

If the 1/8 washers are plugging so are the 19/64 drains. This would cause the heads to run cooler with ¼ washers. If you are running a ¾ feed tube you have a problem in the water pump or leak in the feed tube. That system should have no problem keeping the block full.

[chad202]

measureing head temp between 2&4 (which is in my post) It was running 160ish but now 135ish.

[chad202]

All is good with it now. New water pump and now dumping from all three dumps at idle. Up and running during breakin of the motor with the boat plowing, Temp is 115-120. Now if I could just stay out of the duckseed. :D John, am I ok with the 19/64 dump holes in the exhaust plate, side poppit cover dumping, top of each head dumping with 1/8" thermowashers. Thanks.

[THE FAST ONE]

:) :) I DIDN'T MEAN TOO CONFUSE ANYONE,BUT I WOULD PUT A LOT OF VALUE,IN JOHNS EXPERENCE. MAYBE MOTA'S GETTING TOO MUCH DUCKSEED IN IT.---ED HEY CHAD,GLAD TO HEAR THAT,JOHN SAY'S 19/64 th HOLE'S ARE THE WAY TO GO IN ONE PIECE PLATE.--ED:)

[us1]

All is good with it now. New water pump and now dumping from all three dumps at idle. Up and running during breakin of the motor with the boat plowing, Temp is 115-120. Now if I could just stay out of the duckseed. :D John, am I ok with the 19/64 dump holes in the exhaust plate, side poppit cover dumping, top of each head dumping with 1/8" thermowashers. Thanks.

Yes what you have is perfect if it’s all Nicasil. If it has some steel sleeves in it I shut down or block off the popet dump completely to raise the water temp a bit. You should have 15 to 20 lbs. at WOT. If you email me I can send you a copy of the cooling mods I do but you are already there for a 260 Nicasil block. Good luck.

[chad202]

Yep, all six are Nic. Thanks John and FastOne.

[THE FAST ONE]

HEY CHAD,JOHN'S THE MAN! KOOL--ED:)