FIXX

iTrader: (2)

And jus t to add,,your sea pump is rebuild able..i have done dozens using local parts but your best bet is to use the merc seals,,the local ones dont have a double lip seals..all you need is a press,dont try and rebuild it unless you have one.use a power steeering pully puller to remove the pully..pry out the front seal by poling a hole in the metap part of the seal then install a sheet metal screw and pry the seal out and then remove the snap ring..once the snap ring is removed you will be able to press out the whole shaft and bearings attachet to the shaft..once that is out you will have to remove the 2 other seals on the impeller side...pay attension which direction the inner tappered of the seal is facing and install the new seals in the same direction..its a good time to replace the bearings as well,,they are litely pressed on the shaft..reverst to install the seapump ..you will need2 of # 14 2 of #17,1 of # 18 and 1 of # 19..then merc gear lube..i like to fill the pump 3/4 full of oil,,leaves less room for water if it were to fill up again with either water or fuel..

http://www.boats.net/parts/search/Me...%29/parts.html

tpabayflyer

Thanks a lot, I will order all the pump parts tomorrow and get the pump rebuilt.... Thanks for the tips on pulling it apart, I will take a bunch of pix and take measurements as well... .I did notice a bunch of condensation on the intake manifold and carb when running.....humidity was unusually high and the carb was getting so cold I actually looked to see if I had ice? I guess edelbrock knows what it was doing designing the air gap intake! I did not get a chance to work on the engine today but will get out there tomorrow early..... I have a question, is it ok to run the engine on the hose without using the seawater pump? I want to just clamp the pump outlet hose to the water hose and let it rip? I can setup a gravity feed for the carb so no pump needed and I will have the alternator belt running so the circulating pump will turn? If the same volume of water comes out the exhaust as before I would think its ok?

Griff

Take the rubber coupling off with those exhaust extensions and look up into the risers when its running at idle. You should be able to see if water is sucking back up.

tpabayflyer

I will chek it out..... I have a phenolic spacer with a threaded insert for a wide band sensor that sits under the riser and of course on top of the manifold...... The sensor lasted 2 minutes at idle before it was done.... Wet....I did not check out the starboard side but I assume it was the same as all exhaust ports were equally wet..... If the manifolds and risers check out leak free then the options for me are new exhaust or modified risers. I have already spent money on custom oil lines and brackets for the remote setup of course......

tpabayflyer

I also have the 1" spacer and I could unscrew the 02 sensor plug and check for water ingestion while running....... For now, I am thinking of using some 2 1/2" exhaust tubing and extending the inner riser tube about a foot or so to eliminate any chance of reversion temporarily... I want to tune the carb for a clean idle and warm up the oil so I can change it. I have looked at quite a few pictures of Donzi 26ZX's with 496 exhaust and there is not much extra room to extend the risers........ Maybe 2-3 inches at the most keeping the captain call. Eliminating that would free up all kinds of room to extend the risers....... I also wonder if the old style exhaust elbow may be contributing to reversion? It has a about and 80* turn and maybe the water blasting into it contributes to it backing up a bit and keeping it in suspension? I used the elbows to keep the water mess down to a minimum but I will run it straight out the back and see what happens..... I did find a set of the taller/longer 10 3/4" risers that I will test when I get them next week......

MILD THUNDER

iTrader: (3)

I'd ditch the captains choice. Extend tails all the way thru the transom, full dry. Then install mufflers or down turns if its too loud for you.

tpabayflyer

I do want to keep the switchable exhaust if I can as I don't want to piss off my neighbors..... I may look at welding some extensions on the inner tube of the risers extending them as far downstream as I can... I need to do some testing to see if it will be a workable solution....... I am planning on putting the turbulators back in but I wonder how much heat the phenolic spacers with the O2 sensor port will take from them?

Budman II

iTrader: (1)

TBF, you have to figure that the diverters for the SC are going to put a similar turn on the exhaust flow as the elbows you were using on the stand. You mentioned extending the inner risers, but not sure how you are going to do that with the SC diverter in there, unless you have the engine a lot further away from the transom than usual. I'm facing a similar situation - planning to run a set of Lightnings on mine with the built in SC diverters in the collectors. Still not sure if this will be a reversion issue with my cam, although Bob has expressed some concerns with it. I am also running a MK cam, similar specs to yours, although no 5/7 swap on mine. Wondering if that would have any effect on reversion over the standard firing order?

While you have it on the stand, why not go ahead an hook up the diverters to it and see if they cause reversion in the closed position? Would be a good test before you install it in the boat. You pretty much have to make that decision before the engine goes in, so you can get rid of the Y-pipe if you elect to go straight out the transom. Or you could consider setting it up with the butterflies in the diverters removed and it going full time thru the prop and the transom. This is like the Corsa Qwik n Quiet setup, and it seems to me it would give less backpressure than just going thru the transom, since you have the extra exhaust passage thru the prop. Seems like this would help with any backpressure from mufflers. Thoughts?

tpabayflyer

Quick update, checked exhaust and found no leaks? Pulled valve covers and found what appears to be a bit of "crisco" like grease? tons of moisture all around? Inside valve covers covered in water drops? Rocker arms also covered in water drops from dripping?? This is water drops that in not mixed with oil and clear?? Oil is contaminated and getting changed of course...... All I can think of is this is massive condensation? When I ran the engine last week, it was super humid and the carb and the intake were actually "sweating" condensation and both were cold to the touch? Engine was also very cool and I cold keep my hand on the exhaust, heads, no problem..............

I was not using a thermostat and running off the hose so it looks I was supercooling this motor? Anybody ever seen this condition before? OAT was about 62* at the time and RH way up there.......

So here is what I have done, I got a set of risers with a 2" taller and longer rise.... I am going to use the original 496 turbulators as merc did put them in for a reason and I think I know why....I will also use a thermostat to get some heat in the block...... Time for an oil/ filter change and another run.....

Budman II

iTrader: (1)

Had a similar thing with my 496 3 years ago when first running it on the hose. Was getting lithium grease-looking sludge under the valve covers. Turns out it was condensation, went away when engine got up to temp in the boat. You would be surprised how much moisture can get in the oil with condensation. One of the reasons many have to run an oil t-stat to get the oil up around 200*+ to help boil off the moisture.