riser gasket issues

[celebrity21ft]

searched many hours but can't find my problems so here whats what i do know. We have a 1987 celebrity, with a mercruiser 5.7 260hp motor with center rise exhaust manifold 1.25 riser plate and thru hull exhaust, it was re powered with a crate engine in 2003.During summer commission, it started to leak into the engine. Pulled both manifold and tried acetone testing with plastic over riser flange to seal evaporation. They seam ok for cracks, however the starboard manifold has more warpage than I would like(.005") and appears way rustier than I would like, so upon removal this had a stack of two mercruiser old steel gaskets on top of exhaust riser surface in fact all gaskets on both sides had the mercruiser two weep hole gaskets top to bottom. Is it acceptable to double up gaskets.IT seamed ok for the last 6 years, I guess i don't really want to chance it the manifold is to old to pay for machining. I guess I need a new manifold. After checking here,it appears that I have system type 4b as the service bulletin no. 99-10 states and I should be using a 4 hole gasket on the exhaust manifold riser surface and a two hole/two weep hole gasket on top of the 1" riser plate.So I got oem quicksilver gaskets but I mistakenly installed the two weep hole gasket on the bottom of the riser plate. How will this effect the cooling,keep in mind previously had all weep hole gaskets top to bottom. I have not ran the motor yet. If it has to be changed,should I replace the gaskets or just remove the gaskets and reuse them. It is a 2 hr trip to the store and about 23 dollars worth of gaskets on one side

 

[Bondo]

Re: riser gasket issues

searched many hours but can't find my problems so here whats what i do know. We have a 1987 celebrity, with a mercruiser 5.7 260hp motor with center rise exhaust manifold 1.25 riser plate and thru hull exhaust, it was re powered with a crate engine in 2003.During summer commission, it started to leak into the engine. Pulled both manifold and tried acetone testing with plastic over riser flange to seal evaporation. They seam ok for cracks, however the starboard manifold has more warpage than I would like(.005") and appears way rustier than I would like, so upon removal this had a stack of two mercruiser old steel gaskets on top of exhaust riser surface in fact all gaskets on both sides had the mercruiser two weep hole gaskets top to bottom. Is it acceptable to double up gaskets.IT seamed ok for the last 6 years, I guess i don't really want to chance it the manifold is to old to pay for machining. I guess I need a new manifold. After checking here,it appears that I have system type 4b as the service bulletin no. 99-10 states and I should be using a 4 hole gasket on the exhaust manifold riser surface and a two hole/two weep hole gasket on top of the 1" riser plate.So I got oem quicksilver gaskets but I mistakenly installed the two weep hole gasket on the bottom of the riser plate. How will this effect the cooling,keep in mind previously had all weep hole gaskets top to bottom. I have not ran the motor yet. If it has to be changed,should I replace the gaskets or just remove the gaskets and reuse them. It is a 2 hr trip to the store and about 23 dollars worth of gaskets on one side

Ayuh,.... Welcome Aboard,... Replace the manifolds, or you'll be replacin' the motor,.... Again....

I believe the gaskets should be fully open slots on the bottom 1, 'n the restricted 1 for on top of the riser plate...

 

[04fxdwgi]

Re: riser gasket issues

You can try using a hand held belt sander w/ a fine grit belt to knock down any high spots. The sander has a nice flat plate that will keep the belt flat and fairly true. Have done that before with good success. Just don't over do it.

As far as the gaskets go, I would use the MC "graphite" ones in the configuration they call for. Never had any trouble with them sealing.

I would not reuse any gaskets. After you torque them down, they deform, or crush to the contour and if they aren't exactly perfectly aligned, if reused, they aren't likely to seal. You may get lucky, but for me, it isn't worth the risk. Don't forget, the placement of the weep hole gaskets. Weep holes face fore / aft. Have seen folks put them port / stbd.

Suggestion: Order gaskets online and have a spare set in the cabinet, just incase. Makes life alot easier.

 

[achris]

Re: riser gasket issues

...

Suggestion: Order gaskets online and have a spare set in the cabinet, just incase. Makes life alot easier.

On my shelves I have... A new pair of elbows (with gaskets), 2 set of spark plugs, 2 oil filters, 2 fuel filters, 3 spare props, 4 spare hubs for those props (Flo-torq II), spare engine circ pump, power steering unit, 2 spare drive water pump impellers (and associated gaskets), 40 litres of engine oil, 10 litres of drive oil, a spare timing cover, 3 sump gaskets, a spare sump, light globes, fuses.

In the 'parts' box in the boat are... spare serpentine belt, set of spark plugs, 2 spare prop hubs, spare fuses, spare light globes.

I'm not paranoid, really....

Chris........

 

[celebrity21ft]

Re: riser gasket issues

I dont see how it could have had a weep hole gasket top and bottom of riser for 6 years and be fine but i cant just run it with a open gasket on the top. Will the riser be to hot?This boat see about 10-30 hrs of use per year and I just want to get out on the water this weekend.

 

[04fxdwgi]

Re: riser gasket issues

On my shelves I have... A new pair of elbows (with gaskets), 2 set of spark plugs, 2 oil filters, 2 fuel filters, 3 spare props, 4 spare hubs for those props (Flo-torq II), spare engine circ pump, power steering unit, 2 spare drive water pump impellers (and associated gaskets), 40 litres of engine oil, 10 litres of drive oil, a spare timing cover, 3 sump gaskets, a spare sump, light globes, fuses.

In the 'parts' box in the boat are... spare serpentine belt, set of spark plugs, 2 spare prop hubs, spare fuses, spare light globes.

I'm not paranoid, really....

Chris........

Can I use your garage when I do work? LOL....

Like you, I have a large inventory of spares, but not the extent you have. Spare cap, rotor and plugs (in cabinet and on boat)
, full set of bellows, riser gaskets, fuel and oil filters(in cabinet and on boat), full set of belts (in cabinet and on boat), complete raw water pump kit (in cabinet and on boat), prop nut and washer (in cabinet and on boat), drain plug (in cabinet and on boat) and misc electrical connectors, hose clamps, bulbs, tape and tyraps. And I will always break what I don't have a spare of.

 

[celebrity21ft]

Re: riser gasket issues

I guess my real question some how didn't get answered.If I leave the gaskets for a week or so can it function as i have assembled it as i run it to change the oil again on muffs at around 800-1300 rpm

 

[04fxdwgi]

Re: riser gasket issues

I guess my real question some how didn't get answered.If I leave the gaskets for a week or so can it function as i have assembled it as i run it to change the oil again on muffs at around 800-1300 rpm

I do believe we answered your question. I don't believe reusing the old gaskets is a good idea. You can if you want to, but they may not seal properly and we all know how that will turn out. reassemble and run it right away, or wait a week or even a month. Doesn't matter. Time doesn't make gaskets seal any better since once they are "crushed", what you see is what you get, unless it's a paper gasket and silicone is applied, then it needs to cure before being stressed.

 

[celebrity21ft]

Re: riser gasket issues

I would like to run it with the gaskets as(mistakenly) installed weep hole on bottom of riser.and want to know if it can be run to temp the was it is?will this be bad for the riser? If when disassembled it had weep hole gaskets top and bottom how can it be bad now? of course I will change them before any sea trials.

 

[04fxdwgi]

Re: riser gasket issues

I would like to run it with the gaskets as(mistakenly) installed weep hole on bottom of riser.and want to know if it can be run to temp the was it is?will this be bad for the riser? If when disassembled it had weep hole gaskets top and bottom how can it be bad now? of course I will change them before any sea trials.

Running it on muffs probably won't effect the overall picture, as on the muffs is generally just at idle, or slightly above.
If you plan to run at higher RPM's, I wouldn't do it, plain and simple, as higher RPM will introduce much higher heat load on the manifolds, spacers, risers, flappers and rubber parts in the exhaust stream (you get the picture).

May not effect anything and then again may promote shorter life of parts if cooling water is not distributed as intended.

Your call, I guess. But as I said before, just to save a couple of bucks, I wouldn't do it. I would get the correct parts and install correctly as described to ensure I wasn't damaging anything. But that is me and your milage may vary.

If you are looking for someone to say "Do it, it is pefectly fine", then good luck with that.

 

[NHGuy]

Re: riser gasket issues

Don't chance it, if the gaskets allow water into the exhaust you could hydrolock &/or break stuff. Be smart, sometimes the right thing takes longer. But in the long run it costs the least.

 

[celebrity21ft]

Re: riser gasket issues

90 deg and is it humid , oh well i have to get the boat going by this Sunday ,fresh oil in and l ran up to 120 F and changed the oil and it is running great, I believe the old girl may be back. thanks for all your assistance's, Now I'll have to rush out and get more oil and some new gaskets for that side. Smooth boating everyone