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Help me diagnose the loss of starboard power!?!

Posted: May 29th, 2017, 10:51 pm
by Shipfaced1
Here are the facts:
I'm sorry for the wall of text!
1982 3007 Aft Cabin. 220 crusader motors.
Not a single issue all last season or this season including both short and long trips recently
Starboard side motor died

Ok, spent all weekend on the boat. Went out each day for small trips, long trip today. We ended up cruising about 25 miles one way for lunch. On the way back it got a little choppy as we left the river area we were at onto the big lake so I slowed down from 3400 to 2200 rpm. Normal cruising speed for my boat is anywhere in that range depending on weather and waves. If it is smooth I cruise at 32-3400 rpm which will get me around 21mph. I just made a 5 hour/90 mile trip cruising the whole way at those speeds 3 weeks ago.

So here is where it gets weird. I was trying to beat some weather and it had calmed down a little before it looked like it was going to get worse so I started to throttle back up from 2200 to the 3200 mark and when I got to around the 3000 mark (give or take 100) my starboard motor completely died. I didn't notice it sputter at all, just gone. I throttled the port side down and told my father in law who was with me that we just lost the starboard side. I ended up getting it to start right back up after checking under the hatch and seeing nothing out of the ordinary. Started right back up like normal. I got back up to the 2000 rpm mark and felt it out. Ran like nothing was wrong. Throttled back up and it died out again after giving it some power. This time I was able to feel it starting to go since I was on alert and throttled both down right away and it stayed running. Attempted one more time with the exact same results, sputtered, but stayed running after throttling down quickly. Ran the rest of the 8 miles at 2000rpm and it ran like nothing was wrong, sounded and handled great. So what is going on? My father in law says check the contacts and condenser.

Here is my theory but I am just winging it... my gauges (original 1982) were reading around 1/4 tank on each side. Where is the pickup line for the tanks in this model? I am wondering if when I throttled up, and the bow lifts up, am I starving the motor by moving the fuel away from the pickup line? I just put 20 gallons in each side yesterday. I almost always fill up, and have prepaid fuel at my marina already waiting, but someone recently told me I should stay around half way if I didn't plan on going far to save weight (now that I think about it saving 500lbs doesn't probably matter enough to chance running empty). It ran perfectly fine the rest of the way at 2000rpm, and back at the dock it throttled right back up to 3500 rpm with no problem and held there. Am I lucky enough it's just low fuel?

Re: Help me diagnose the loss of starboard power!?!

Posted: May 29th, 2017, 11:30 pm
by km1125
I'd be thinking fuel filter problem and you're trying to consume more than the partially-clogged filter can provide.
If that'
Are you saying "back at the dock it throttled right back up" when it was in neutral? If that's the case, then there's no real fuel draw there.

Re: Help me diagnose the loss of starboard power!?!

Posted: May 29th, 2017, 11:37 pm
by bud37
There are two things that stand out from your story.....one it started to get a little rough, so with the tank down could have stirred up the bottom and your anti siphon valve could be plugged, remember between 2000 rpm and 3200 that is a very high load zone ( loads of fuel needed ).....so the rest at 2000 where your fuel needs are much lower would make sense.
I don't think I would consider the fact that you could rev it at the dock to 3500, that would require very little fuel ( no load)....your father in law could be right as well, but check the anti siphon anyway, that will cross it off the list......thats all I got,there will be others along.... good luck with it.....

Re: Help me diagnose the loss of starboard power!?!

Posted: May 30th, 2017, 7:48 am
by Shipfaced1
km1125 wrote:Source of the post I'd be thinking fuel filter problem and you're trying to consume more than the partially-clogged filter can provide.
If that'

I had considered that as well and they haven't been changed since last season anyways so it will be one of the first things done regardless. Thanks for the input!

bud37 wrote:Source of the post it started to get a little rough, so with the tank down could have stirred up the bottom and your anti siphon valve could be plugged,

That honestly never crossed my mind. This is why I come to the forum, this is my first larger boat and there are plenty of things that I am still learning. Thanks and I will definitely check out both valves while I'm at it.

Re: Help me diagnose the loss of starboard power!?!

Posted: May 30th, 2017, 8:39 am
by waybomb
Agree with filters and anti siphon valve, but I disagree with pops
You never know what can happen.i top it up. After every trip.
I doubt you could measure the difference in fuel burn based on weight with a normal instrument.
Even a small carver weighs 8000 pounds. Fifty gallons of fuel weighs 300 or so.
I'd rather be safe than trying to save a few dollars.
Plus, there is no condensation in a full tank.
A boat sitting for days with a partially full tank will have condensation forming every morning