Fishermark
Vice Admiral
- Joined
- Oct 19, 2003
- Messages
- 5,617
1990 Glastron with 230A engine - (also known as the AQ131)
I have a curious problem with this boat - hope my fellow Iboaters can help me! This engine starts fine and gets up to speed with no issues. After a few minutes (maybe five) at around 3- 4000 rpms, the boat starts to stumble and eventually dies.
This has happened since I "resurrected" this boat. (When I bought it, it was in bad shape). I had siphoned all the fuel I could originally then put in fresh fuel and a water separator. At first, I simply chalked it up to some lingering water and gunk in the tank. In fact, I confirmed it by changing the water separator canister. The boat ran great again with a new filter canister.
But after a couple times of this, I figured something else must be the problem. I poured the fuel out of the old canister and it looked fine. No water or gunk. I screwed the old filter back on - boat ran fine for another five minutes. When I listen carefully as I unscrew the canister, I can hear air hissing in, like a vacuum has been released.
Here's the curious part. Everything on the fuel tank and all hoses are brand new. New filler hose. New vent hose. New check valve in tank fitting, along with new nylon tube. New fuel lines from tank to filter and filter to pump.
Last time it did it I tried removing the gas filler cap. No difference. Still a vacuum when I unscrew the filter.
Bad anti-siphon valve? It is brand new, but maybe bad from the start? Weak fuel pump?
I am going to remove the ant-siphon valve and install a regular barb fitting first and see if that solves the problem. (At least for diagnosing purposes).
But thought I would check here to see if anyone else has a suggestion. Thoughts?
Here's a few pics of my set up...
I have a curious problem with this boat - hope my fellow Iboaters can help me! This engine starts fine and gets up to speed with no issues. After a few minutes (maybe five) at around 3- 4000 rpms, the boat starts to stumble and eventually dies.
This has happened since I "resurrected" this boat. (When I bought it, it was in bad shape). I had siphoned all the fuel I could originally then put in fresh fuel and a water separator. At first, I simply chalked it up to some lingering water and gunk in the tank. In fact, I confirmed it by changing the water separator canister. The boat ran great again with a new filter canister.
But after a couple times of this, I figured something else must be the problem. I poured the fuel out of the old canister and it looked fine. No water or gunk. I screwed the old filter back on - boat ran fine for another five minutes. When I listen carefully as I unscrew the canister, I can hear air hissing in, like a vacuum has been released.
Here's the curious part. Everything on the fuel tank and all hoses are brand new. New filler hose. New vent hose. New check valve in tank fitting, along with new nylon tube. New fuel lines from tank to filter and filter to pump.
Last time it did it I tried removing the gas filler cap. No difference. Still a vacuum when I unscrew the filter.
Bad anti-siphon valve? It is brand new, but maybe bad from the start? Weak fuel pump?
I am going to remove the ant-siphon valve and install a regular barb fitting first and see if that solves the problem. (At least for diagnosing purposes).
But thought I would check here to see if anyone else has a suggestion. Thoughts?
Here's a few pics of my set up...


