Uggg FRESH REBUILD WATER ONE PLUGS HELP PLEASE

[Heavy Sausage]

Hi, I am running a 260 porting on a 2.5 and 2.4 carbs just put motor together and did my brake in pulled plugs and there clean/ no i mean clean as in steamed clean. Water in all 6 it looks like! Brand new headgaskets all done to specs. WTF can be causing this?? And what jets should i be running i have 90s in there now and its just not right fealing. Im sure the water isnt helping alot. Boat seams to run ok not right but it runs, im lost. PLEASE HELP AND THANKS


(one more thing tank was empty and out so i know its not water in gas tank)

hehe sposta say water on not one

[Dean Dorsey]

If you are sure you are not leaking at the head gaskets here are 2 more areas that gave me hell when I ran 260s in terms of water leaks and steam cleaning my piston tops. Base gaskets for me were the problem, if not sealed perfectly water can be scavenged back around the exhaust outlets and up into the bores. #3 a hairline crack in the exhaust divider plate happened once and caused this problem for me. Big problem was I could not see the crack it would only open up under pressure. They can be pressure tested, also the tube gasket in the divider plate when faulty can cause this problem. John Marles on this site is a guy that can help a bunch as he did with me.
Good Luck, Dean

[bahamatrama]

I had the same thing happen to me on my 280. I replaced the divider and gasket

[Heavy Sausage]

So start with the exhaust divider gasket, if not that then the base gasket. I hate how I have to run two of them with the pan and cowl for this thing. I do have to run two rite ? one under the pan and one over correct ? Im such a newb at this stuff. Thanks all for help please keep the reasons and ideas coming.

[Dean Dorsey]

Yep two base gaskets in the places you mentioned, do not reuse them. The ones with the metal in the middle work best, some aftermarket gaskets do not have a metal sub structure. Make sure surfaces are clean and free of defects ie, grooves chips or warped which can also create the problem, dented pan can also create havoc. I also always used a good quality gasket seal on surfaces as well. Pay special attention to the areas of wear around the exhaust outlet surfaces on the gasket for wear. Might want to start with the exhaust divider as pulling the powerhead and replacing gaskets is not cheap, expecially if it is not your problem. You can test for a leak in the base gaskets by pulling the lower, run it on a hose useing a flash light and willing to get wet as you look up to the sealing points through the mid, you can usually see water seaping out of those points if there is a leak. Sometimes it is best to have a second person to bring up the RPM's to create additional water pressure, as sometimes leaks will not show at 2-5 psi. You can do a search for this test in the Tech discussion forum for more specifics. On the divider I tried to do a pressure test myself to check for a hairline crack, but could not replicate enough water pressure to see the leak, but another with the propper equipt. did and was able to find it for me useing heat and additional water pressure. Like yours when I had this problem it started fine, idled normal but sounded fouled when hammered to get on plane, in the mid and lost performance on top. If you have EGTs it shows up well there. I never had a leak in all 6 though, this may be something more or a very big problem with a leak like I had that should be easy to find. Hope this gives you some direction. Dean

[ChrisXS2003]

Do you have the right divider gasket?

The gaskets for the 280 and 260 are not interchangeable. The exhaust chest is different at the water transfer openings. The sides of the chest in the 280 and drag are smooth. The earlier 260s are stepped out into the chest.

Chris

[Heavy Sausage]

I got the gasket from a guy in town, I think he might have sold me the wrong one. It didnt fit rite from the start im thinking Ill start there. Thanks all for the replys this is great feadback. Also does anyone know what jets (main) I should be running in a 260 2.5 with 2.4 carbs on it? I have 90s in now.

[Jay Smith]

IMO :

The 2.4 carbs will starve a 2.5 and eventually will fry it ....No matter how BIG a jet is used the size of the carbs ventura will NOT properly mix the hugh amount of excess fuel your trying to make shift to that engine as the jets can only be enlarged so big and then the smaller air capacity simply cannot properly blend or mix the fuel/air ratio you then end up with a slobbery fuel fat bad actor that NEVER will perform properly... Go to a proper sized 245 HP 2.5 carb , or I have some customers that retro a 3 litre carb on the 2.5's.. I'd NEVER try to run a too small carb and try to over jet it to make it work on a bigger CI engine that will demand more carb... IMO your heading for disaster...

What the other guys told you about the water leak is right on track, you MUST use 2 NEW base gaskets and the divider plate gaskets must match the proper divider plate.. Also if using a 2.4 tuneradapter plate and it has be ground on so that a smaller 2.4 is opened to mate the 2.5 powerhead the gasket in the rear of the water to exhaust side of the exhaust passages will soon fail and draft water directly into #'s 5 and 6... SORRY BUT I'm a system matched freak and I have hardly EVER seen scabbed on pieces that are not designed to be mated work for long... The end result is the money that a person tried to save ends up costing more to repair and you'll have to buy the correct part in the long run anyway why not do it the first time and had no issues ?

Good luck,