[Phlorida]

Chris - The "P" in "BPR" stands for projected tip which ostensibly provides better performance. If they have been in the boat for a few seasons I would go ahead and swap them though the projected tip is unlikely to be the issue.

[chriscorbett]

My mechanic is all but giving up now!

He says there is a spark at the plugs for just the first revolution of the engine but then it goes and he can't work out why.

He is now suggesting replacing the ignition module which is Very expensive i.e £460.

I'm still hoping it's something simpler lie the lanyard switch or ignition switch?but I don't know how to test for those?.

At this stage the Distributor cap, sensor,coil,and positive lead to teh starter have all been changed.

Any ideas.

[SEMIJim]

Originally Posted by chriscorbett

My mechanic is all but giving up now!

He says there is a spark at the plugs for just the first revolution of the engine but then it goes and he can't work out why.

He is now suggesting replacing the ignition module which is Very expensive i.e £460.

Yeah, they are , I just did some superficial research on MerCruiser ignition modules. What I found was not encouraging. Suggest you enter "MerCruiser 454 ignition module" into Google and do some studying.

Originally Posted by chriscorbett

I'm still hoping it's something simpler lie the lanyard switch or ignition switch?but I don't know how to test for those?.

Your mechanic should know how. It really shouldn't be hard. (Personally, I doubt it's either of those, but I'd never say never.)

Originally Posted by chriscorbett

At this stage the Distributor cap, sensor,coil,and positive lead to teh starter have all been changed.

Positive cable to the starter? That wouldn't affect spark.

Originally Posted by chriscorbett

Any ideas.

I've told you two or three times already: Find a mechanic that knows what he's doing. It sounds like this one is just throwing darts blindfolded. Is he even a certified MerCruiser mechanic? Or learn how to do it yourself.

Jim

[mikeyt]

+1 on Jim's comments.

[chriscorbett]

Well guess what!!...I fixed it myself!!

Bought myself a battery jump pack,spark test plugs, and new leads. Fitted the leads, went round each of them with the tester and I could see that there was spark there but it still wasn't starting.

I could smell plenty of fuel so I fugured it couldn't be fuel. So I guessed it must be air.

I opened the choke plate on the carb and kept it open with a screwdriver , turned the key and it started!!

Starts every time now as long as the choke isn't on or as long as the plate is kept open a bit. Runs much better with it wide open though.


So , happy days ....but how do I fix the choke , it seems to operate from a round thing at the bottom left of the carb which has a black and a purple lead running from it that also run to the hour meter.

I have no idea how all that works I've simple tied a bit of wire round the linkage to hold it open.

Can anyone enlighten me on the rest please. Thanks guys

[SEMIJim]

Originally Posted by chriscorbett

Well guess what!!...I fixed it myself!!

Yay!

Originally Posted by chriscorbett

I could smell plenty of fuel so I fugured it couldn't be fuel. So I guessed it must be air.

BE EXCEEDINGLY CAREFUL! Having plenty of gasoline fumes around is how boats blow up. Just had this happen Friday to somebody in our club. He's okay, thank God, but his boat is totaled, his slip neighbours to either side suffered extensive damage and the finger dock his boat shared with another will require extensive repair.

I cannot emphasize this too greatly: Gasoline fumes and boats are a very, very bad combination.

Originally Posted by chriscorbett

I opened the choke plate on the carb and kept it open with a screwdriver , turned the key and it started!!

This is kind of odd, because most carbureted engines require they be choked when they're cold.

Originally Posted by chriscorbett

Starts every time now as long as the choke isn't on or as long as the plate is kept open a bit. Runs much better with it wide open though.

Well, yes, it would--once it was warmed up a bit.

Originally Posted by chriscorbett

Can anyone enlighten me on the rest please. Thanks guys

It's an "electronic" choke. That "round thing" has power applied to it when the key is turned to "run." It eventually opens the choke. Or it's supposed to.

Btw: Sounds like your mechanic was completely on the wrong path. Imagine my surprise

Jim