Self inflicted reversion??
09-23-2023, 04:12 PM
#1
Registered
Thread Starter
Self inflicted reversion??
I removed the exhaust from both engines and found water in the back 2 cylinders (of the exhaust manifolds) both sides of both engines. The good news is I now know what took out my 02 sensors. 20 years ago or so my wife and I took a ride with a salesman on PQ 290. When he came off plane, he would hit the throttle (maybe 1500 rpm or so) when the wave hit the back of the boat. He said it would keep the water from getting up into the exhaust. Made sense at the time and I have done that ever since. Fast forward to this year and the first time out with the new straight through tips I loose both of my 02 sensors. Don't think much of it as everything is new this year and I guess things like that can happen. The new 4" tips have the rubber reversion tabs in them and NOW I understand what probably happened. The first time I came off plane I of course hit the throttles to keep the water out not thinking that that action also moves the rubber reversion tabs up and out of the way and water got in. With the stock muffler tips installed for the first part of this season I didn't have any problems. These new tips will accept muffler inserts however that defeats the purpose of the new tips. I am thinking I will look around and get some rubber hose and clamp onto these tips for turn downs. Anybody running rubber hose turn down's and if yes, (I feel your pain) where did you get them?
10-03-2023, 02:33 PM
#2
Registered
Rather than completely closing the throttles when coming down off plane I stop them at 1500 rpm until the wave catches up. When it dissipates I proceed to lower rpm, that way it doesn't "blow the flaps open."
The following 2 users liked this post by Tractionless:
Indy (10-03-2023), PQ290Enticer (10-07-2023)
10-03-2023, 02:41 PM
#3
Driver-441
Racer
People who "rev" their engines can cause reversion. You slam the throttle plate shut at 3k plus and the vacuum shoots to the moon. Ittl suck water up that exhaust like a pump.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
The following users liked this post:
PQ290Enticer (10-07-2023)
10-03-2023, 09:11 PM
#4
Registered
People who "rev" their engines can cause reversion. You slam the throttle plate shut at 3k plus and the vacuum shoots to the moon. Ittl suck water up that exhaust like a pump.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
10-03-2023, 09:12 PM
#5
Registered
People who "rev" their engines can cause reversion. You slam the throttle plate shut at 3k plus and the vacuum shoots to the moon. Ittl suck water up that exhaust like a pump.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
CMI recommends on shut down bringing engines to 25-3500, turn the key off with the throttle still advanced. It will clear any water out of the exhaust. Its a great prractice to get into ESPECIALLY for people whos exhaust gets buried pulling the boat out of the water.
