Engine bogs

[HuskyDavidson]

I just bought a fuel injected 240 Hp 2001 Islandia, Pretty nice shape for 20 year old boat. Before taking it out I had a service done. plugs, filters, gearbox.
First time I’m filled it up fuel shot out the filler hole when it got near the top. The service station attendant said the fuel should had come out the vent hole..Vent hole? There is what looks like a vent near the filler.
So I’ve taken out 3 times for about 15 gals each time.
when I crowd the throttle the engine bogs..
my question is does the fuel tank have to vent to run properly?
Show I try running it with the filler can loose or is something else wrong (Head temp sensor or something)
Thanks for responding ahead of time.

 

[abnwayne]

yes the vent needs to function in order for the boat to run as designed think about the engine as if you are drinking from a sealed container eventually vacuum will become so strong you wont get any more fluid out same principals apply. tank vent needs to let in fresh air or the engine cannot suck fuel out of tank

 

[HuskyDavidson]

Thank you! That’s seems to be common a sense thing that was in the back of my mind after the first fill up.. But I was blaming it on bad gas since the boat had sat a year. I’ve put in Sta-Bil fuel conditioner and Mercury’s system cleaner along with 91 ethanol free gas..
I’m going to take it out in a couple of hours again with the cap loose to see if that’s the issue.. I believe those vent tube end caps have a ball valve. the breather side hole in it is not pointing down.. it’s about 45 degrees pointing towards the bow.. I wonder if that could be a cause of it not venting?(easy fix just rotate a little)..
But now my main concern now is have I over heated and damaged the power head because of a lean condition?? Finger crossed.
It was smoking a lot.
Any thoughts Wayne?

 

[abnwayne]

its tough to say a good compression test will tell you the general state of the powerhead along with a good plug reading. bog could be fuel or air pressure

running without gas cap will tell you if its a venting issue though

 

[HuskyDavidson]

Yea thanks I’m up here in Parker Az. (Just south of Lake Havasu) (shops have a min of 30 day waits) .. I’m going to the ramp in 30 min.. just hoping it runs smooth with no bog.

 

[HuskyDavidson]

Took it out.. no difference.. guess I’m going to have to wait to get into a certified mechanic..
thanks for your help Wayne.
Jeff.

 

[Tim75]

Took it out.. no difference.. guess I’m going to have to wait to get into a certified mechanic..
thanks for your help Wayne.
Jeff.

Have you done a compression test? All spark plugs out, WOT.

While the plugs are out, change them.

Check fuel pressure at the test port (tire valve on top of the vst)? Should be 36psi.

Have you tried running with the hatch open? Some boats starve for air. Just a test.

Good luck finding a mechanic that will work on your boat. That's why we are all here.

 

[HuskyDavidson]

Thanks Tim, I had the boat in a shop in Havasu. I had called round up there and most wouldn’t touch it. And most shops were booked out at least a month anyway. I found a shop and After a 2 week wait, they had it for 10 days. I asked for it to be serviced. Supposedly plugs, filter and gearbox oil was changed...I should had asked them to take it on the lake and run it, then give me the news. I did ask for a compression check which I didn’t get...so not happy with the results.
I did find a shop in Parker close to me, the guys shop has been here over 20 years, and he said he was “mercury certified”, And had no problem working with the “Sport Jet”..so he’s next..
One of my neighbors up here had died and his kids held an auction, I bought this boat with no knowledge of the sport jet.. I just thought It looked in good shape and I wanted a Jet powered boat for the River.. Lotta guys use I/O’s these days but they also run over stuff.. Jets are the best bet in my book.
Right now it’s looking like a good looking nightmare.
I’m going to be gone for 2 weeks on business so I’ll have to deal with it when I get back.
Thanks again Tim.


Have you done a compression test? All spark plugs out, WOT.

While the plugs are out, change them.

Check fuel pressure at the test port (tire valve on top of the vst)? Should be 36psi.

Have you tried running with the hatch open? Some boats starve for air. Just a test.

Good luck finding a mechanic that will work on your boat. That's why we are all here.

 

[HuskyDavidson]

@Tim75 I will I’ll be coming here a lot trying to acquire knowledge. I appreciate your contributions.
I’m coming from a place of zero experience and knowledge of these hulls and power plants.. I haven’t power-boated in 40 years. Most of my water experience is sailing.
I’m looking forward to enjoying this boat. And meeting new people here.

 

[abnwayne]

One more thing to check is to make sure all of your fuel pumps are turning on when key on engine off I found a bad low pressure pump in my boat would start and idle great couldn't get it above 3k rpms though without that pump

 

[HuskyDavidson]

One more thing to check is to make sure all of your fuel pumps are turning on when key on engine off I found a bad low pressure pump in my boat would start and idle great couldn't get it above 3k rpms though without that pump

Thank you Wayne, I will check into that.
Jeff.

 

[Jcmetz]

My 06 sportster 4 TEC did this. Change the coils too. It runs like new now. No more bogging down and engine surging / rev like it had a mind of its own.