1999 SN 196 GT 40 Boss Backfiring and Bogging

[OldSilverback]

Dropped the boat in the water this weekend for the first time and boat fired up and ran smoothly for about 10 minutes. I always take care to warm up engine and check all the gauges- no troubles at the start . After 10-14 minutes engine started to bog and backfire. Then it wouldn't start. The next day it did the same thing- ran fine for 10-12 minutes then bogged down and backfired.

My first thought was lousy gas. Drained some out and put in fresh with Seafoam. No change- runs smooth for 10-14 minutes then dies out. I will put in a new FCC filter and change the relays this week- any other suggestions??

I have read some folks have problem with the small fuel hose inside the FCC- what size/diameter is the hose? Do I just use hose clamps to secure it? If I have the FCC canister off I assume folks here recommend changing this out.

Also,it could be the anti siphon on the gas line. I haven't seen a picture of it on this site. Where is this located? Do I need to remove to clean it? Do I need to empty all the gas from the tank?

Any suggestions or pics would be welcome.

[charlesml3]

Have you ever replaced the distributor cap and rotor on that boat? Mine did the same thing a couple of years ago (1999 GT-40). Turns out, the distributor cap was completely worn out. I just redid it all. New cap, rotor, plugs and plug wires. It isn't terribly expensive.

Anyway, flip that cap over and look at the inside. If it's the original one, I'm betting the contact pads are all worn and pitted.

-Charles

[TX-Foilhead]

Not something you typically hear about on those boats, but check the coil when it happens to see if it hot. A bad coil will heat up and get weaker the hotter it gets which causes those kind of problems.

[Mamigacz]

make sure the fuel pressure is within spec.