last night i went over to help Jay with motor#1. All i can say is that this motor has suffered the same fate as motor#2. after trying to crank it over a couple of times it clunked and Jay immediately stopped cranking it. i pulled out the #5 spark plug and to no surprise found moisture in the cylinder. after draining the oil out of the motor, yes, there was water in the motor.
the same "friend" who did the other risers did these also. to make matters worse as we were starting to pull all the plugs and spray fogging fluid in the cylinders it started to pour. right now we're stuck till friday since Jay is waiting for the rest of the parts to finish it up. when we pulled the risers off the gasket itself was wet on both sides and it wasn't even crushed or anything. the riser was bolted on to the manifold. it seems as though the riser never mated correctly to the manifold. other than the "friend" factor, is there any reason they wouldn't seat properly?
has anyone ever had this kind of problem where the risers wouldn't seal?
i'm just trying to cover all angles. to me putting on risers is pretty cut and dry. unfortunately i didn't do the job the first time and right now Jay's biggest fear is that when we put them back on they'll leak again. any suggestions would be helpful.
thanks to everyone

Russ

Get some extra gaskets, they are cheap. Put them all on and then take them off and inspect them to make sure they are all crushed. The new ones you are going to get are much thicker then the old ones. Make sure you torque them all down then retorque until they stop tightening. After I run them for a heat up and cool down I go back and recheck them all. Good luck you guys.

Jon

make sure the riser bolts are not bottoming out in the exhaust manifold, this can be a problem if the risers / minifolds have been resurfaced to aggressively or if you get a little water/rtv/grease what ever in the holes causeing a hydro lock of the bolt

Merc also uses odd bolt lengths in a lot of places eg, the riser bolts on the old style risers are 5 3/4 " not 6 ", don't know the length of the short ones

whats up Jon
Jay has some brand new gaskets coming in from BAM today
the gaskets we pulled off last night were actually new as well
they don't look used at all. i told him we could probably reuse them but he feels more comfortable with brand new, straight out of the package gaskets. can't blame him at this point.

ursus
today he's ordering brand new mounting hardware. i have a feeling the bolts that were being used may have contributed to the leaking, but its hard to tell. the "friend" never resurfaced the risers and manifolds which is also a contibuting factor to the leakage

i'm just trying to cover all bases here. Jay is a little fed up so i told him i'd post for him today. try to get some advice. hey, what are friends for thanks for the tips guys

Russ

even tho the friend never resurfaced them I seemed to recall Jay mentioning buying used risers on a previous thread. Sometimes if the risers are kinda ruff/corroded folks will take 1/16 of an inch off them to clean them up, this can cause the bolts to bottom out, depends on the manifold etc, just thot of this when you mentioned the gaskets were not crushed

I siliconed mine. Also found that two of the bolts were too long and were bottoming out.

didn't he make those risers??? did he/you anyone ever check to see if they got tweeeked during the welding??? and WHY,,,if you knew he f'ed up the one side,,,,,did you check the other????

If I remember correctly, Jay is using Mercs stock stainless steel risers. They have the short bolts holding them on. I know Merc had many problems with these leaking and stopped making them. I would definetely check the surface especially on the stainless riser using a straight edge to make sure it is not warped. I hear the leaking problems were due to the rate at which the cast iron expands when heated vs. the way the stainless expands.

Scott

yes they are the stainless risers. we're going to take a straight edge and a feeler guage to check it out. i think merc says there can't be anymore than .003 difference for every inch. they were purchased used as well. supposedly they have really low hours on them too. i don't remember the exact number.

what Jay did to the risers would in no way effect the sealing at the manifold. he did the custom work on the exhaust side. besides, all he did was put a tube in the exhaust side of the riser to extend it to the transom. last night was the first night i was over in a while. motor#1 ran rather well at first, then it developed a backfire through the carb. i never thought to check the risers first because the motor did run to a certain extent. motor#2 never even ran. #5 cylinder filled with h2o while trying to start it.
thats why motor#1 wasn't checked right away. it did run

Russ

What cylinders were wet/filled on motor #1....or didn't you get that far yet??

The middle cylinders will ususally be the ones to fill when you have a riser leak problem. (for example: #5 on motor 2 that was full).