Dry firing new engine

"Just had a new 360 long block

"Just had a new 360 long block put in my 34'silverton. Before taking it off the blocks and having it hoisted in the water the young mechanic wanted to dry fire the new engine for a test. When I asked about hooking up water for cooling he said the eng. was fresh water cooled with anti freeze in a closed system, just watch the temp. gauge, shut it off at 160 degrees, we were only doing a quick test. Soon after discovered he had melted the raw water impeller. Now after fixing that and the boat in the water, when I shift the boat ingear, forward or reverse I have a horrible banging noise on each revolution of the the eng.,sounds like a bolt not tight. Pulled the inspection cover allbolts seem to be tight on the flywheel. Could the flex plate be installed backward? Could the water pump in the tranny be also burned up, even when the mech. dry fired the eng. it was not put in gear? FYI,the 71 series tranny and V-drive ran good before eng. replacement. I did unhook the prop shaft for drill and trouble still there. Noise is still there at idle or higher rpm. Thanks, Steve"

"Running it out of water is no

"Running it out of water is no problem but he should have took belts off because thats what happens It burns the impellors right up,I would only have ran it a few minutes though,I have a 34'silverton to and do all the work on it youll need to make sure no chunks of the impellor are stuck in the heat exchanger as well...Water just flows through the rear there is no pump the flex plate can go in backwards just put one in not backwards my old and new needed trimmed to fit it states on it flywheel side not sure if it will bolt up right though Did they use the old plate if its no right its a days job in the boat.
One thing look in the inspection hole if your looking at the plate you should see the springs
protruding towards the drive if you look down and you cant see them its in backwards again not sure if it will bolt up though but am positive it will slip on backwards believe though you may have a new plate not trimmed please let us no...."

"Russell, Thanks for the respo

"Russell, Thanks for the response. The exsisting flex plate was used,although I did need a new ring gear. Aside from the eng. raw water pump,lesson learned the hard way, I was concerned that the tranny had a raw water pump that was also affected even though it was not put in gear when the eng was dry test fired, and yes the eng. was only run a few minutes at most till it came up to 160 deg. The boat is 7 hrs away, won't be able to check inspection cover till I get back next week, but off hand don't remember seeing springs. Still afraid it all has to come out again but still open for ideas. Despite current issues still like the boat just hope I can resolve before tuna season. Thanks , Steve"

Tranny does not have a seperat

Tranny does not have a seperate raw water pump.
Its also unlikely a flex plate issue as noise only occurs in gear. Check the coupling to the prop shaft.

Also where does the the noise appear to be coming from? Its always possible (though unlikely) that the prop is hitting the rudder.

"Robert, I did disconnect the

"Robert, I did disconnect the prop shaft and noise was still there. Hard to really tell if noise is coming from bell housing or tranny. Either way I'm afraid eng. and tranny still have to come out. Thanks for the thoughts, any other imput is appreciated, I'll keep you guys posted, Steve"

"Only safe way to go, unfortun

"Only safe way to go, unfortunately. It wouldn't be good to have loose parts blowing a hole in your hull!

Jeff"

You can check the shift linkag

You can check the shift linkage may sure its all the way forward and back when in the gear selected if in doubt remove both from your problem side have someone start it while your below and only at idle manual shift see if the noise is there only ideas as I said I have the same boat...Just curious did you mechanic
seperate the trans and drive there are bolts in there that connect another set of couplings though you dont have to take them apart to seperate maybe he did??Also you can remove the trans and drive while in the water though you should do one at a time there heavy as ???? together keep us posted we all learn from these things..Ps may sure the fluids are full as well..

"Steve, Not sure of your v-dri

"Steve, Not sure of your v-drive set up but mine has two u-joints between the tranny and gearbox. If one is bad you could hear it."

"Well guys I'm leaving for

"Well guys I'm leaving for the boat Sunday. The boat yard does have a crane and will pull the eng. and tranny while the boat is in the water on Mon. I will check the u-joints but don't remember seeing any between the tranny and v-drive I'll also check the linkage before pulling the unit. I have an old 360 and tranny I bought for parts. I did seperate the bell housing and it is possible to reverse the flex plate, still my guess. My nightmare is I'll pull it all out and ever thing looks good. May bring the lap top with me to stay in touch, if not I'll let you guys know. Thanks, Steve"

Good luck!

Jeff

Good luck!

Jeff

"Hey Guys - Just signed on and

"Hey Guys - Just signed on and have a very similar problem. On starting the boat last week (first time for season-late this year) there was a "clunk-clunk" when in gear, not in neutral. Disconnected prop shaft, same thing. Velvet drive was re-built year ago, so thought that was problem. Removed and took to rebuild guy. He opened it up and pronounced it "cherry", no problem. I cannot find any schematic on bell housing and torque plate (or drive plate) From what I can see, it looks great, no rust on springs, no burn marks or apparent loose parts. Should I remove the bell housing? What should I look for? Any suggestions and/or links would be appreciated. Thanks much, Mike Flood, Clayton, NY"

Most likely your engine is idl

Most likely your engine is idling too rough--that'll do it.

Jeff

"Well Guys, I just got back fr

"Well Guys, I just got back from the boat and all is well. Of course there was the $920 to R & R the tranny and eng, but the boat does run out good now, just hope the tuna show. The problem was a bad flex plate. The young mech. did not inspect the flex plate to find obvious slop and movement between where the spline enters the plate and the springs in the plate. Lesson learned, he may be a fair auto mech. but between burning up my raw water pump and sloppy if any inspection of my flex plate if you need an airplane fixed go to an airplane mech. if you need a boat fixed go to a marine mech. Thanks for all your input, Steve"

" Car mechanics should not

" Car mechanics should not be allowed to touch marine engines...This is a recording" (click)