SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: throttlejunkie on June 16, 2020, 12:24:07 PM

Title: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 12:24:07 PM: I’m having a big issue, I got an 85 carrera 205 that will run fine on a hose, but as soon and it’s in the water it runs like total shit then not at all. This is with it on the trailer still just backed up far enough that the pump and exhaust are in. The motor was just rebuilt last month as a long block and hasn’t even been broke in, Heres the specs:
454 BBC roller motor w/mild cam
Weiand intake
Quick fuel 750 dp marine carb
DUI marine HEI distributor (timed 10-12 initial, 34-36 total)
Ac delco plugs gapped at 50
Indmar through transom exhaust
High torque mini starter
Rebuild Berkeley 12JG with ride plate and electronic jetovator

There doesn’t seem to be any wires touching the water or anything when I back it in the water on the trailer, it seems to me like the ignition shorts out when in the water somehow, but I’m completely perplexed on how that could be a thing, I thought maybe the starter is shorting internally causing it to somehow short through the block when the exhaust tips or grate are in the water? I can pull it out on the launch ramp, wait a minute or so, then it runs normally, but the second I back into the water ( even when still running) it idles like shit, has no power and eventually just dies then can’t be restarted til I pull it out of the water. If anyone has any ideas or has been through this before please let me know, here are some pics
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 12:26:39 PM: What does your oil look like

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: eliminatorbuild on June 16, 2020, 01:30:11 PM: So I’m imagining that when your boat is on the water hose your boat is on flat ground but when your on the launch ramp you boat is at an angle. It makes me wonder if your float in the carb is stuck or something and your starving the engine of fuel.
Just my thoughts and possibly something to look at.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: Tikotiko on June 16, 2020, 01:44:44 PM: A buddy of mine described the same problem and i dont know how but it was his starter solenoid. It made no sense to me but thats what he said. Im calling him now. Brb

Sent from my SM-G975U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 01:49:17 PM: So after I first put it together the intake was poorly sealed and leaked water into the oil when I first started it on the trailer, but I realized very quickly, and pulled and resealed the intake and drained the milky oil and cranked what was left out with the oil filter off, then put new oil and filter, so there’s probably a tiny bit of that milky oil still in it, but otherwise it looks pretty damn clean. I probably should have mentioned that. As far as the float level is concerned, I have glass sight bowls in the quick fuel carb and they’re adjusted right to the middle and still look good on the launch ramp, fuel pressure is at 6.5psi at idle. I don’t think it’s flooding
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 01:49:45 PM: Is it a mechanical or electric fuel pump

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 01:59:15 PM: Holley mechanical pump with regulator and gauge on rail
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: mobboss on June 16, 2020, 02:01:16 PM: is it cranking over , fine in the water???? or does it crank slow??

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 02:32:26 PM: Seems to crank the same in and out of the water
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 02:35:25 PM: Check the fuel levels in the bowels by removing the sight screw after cranking it until you get pressure

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 02:36:19 PM: Duel should dribble out if they are set correctly.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 02:37:18 PM: You may have to shake the boat side to side to get the fuel to dribble

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: mobboss on June 16, 2020, 04:58:57 PM: i maybe completely wrong but the common denominator here seems to be your jet. when its loaded???

Sent from my iPhone using SoCal Jet Boats
Title: Runs fine on hose, won’t run in the water. HELP!
Post by: mobboss on June 16, 2020, 05:01:07 PM: if its not that id check to make sure your NOT dumping fuel, down the carb!!

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 07:26:51 PM: It’s not a fuel issue, floats are adjusted correctly and fuel pressure is at 6.5 psi running. I don’t believe it’s a pump issue either since it cranks fine in the water and can’t be restarted once it dies leads me to believe it’s a electrical short but that’s why I’m scratching my head, doesn’t make sense that it would short when touching the water
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: eliminatorbuild on June 16, 2020, 07:47:24 PM: Quote from: throttlejunkie on June 16, 2020, 07:26:51 PM
It’s not a fuel issue, floats are adjusted correctly and fuel pressure is at 6.5 psi running. I don’t believe it’s a pump issue either since it cranks fine in the water and can’t be restarted once it dies leads me to believe it’s a electrical short but that’s why I’m scratching my head, doesn’t make sense that it would short when touching the water
So this doesn’t make sense to me and I might get shit for saying it but here we go. I was talking to a buddy of mine about your problem. He seems to remember a friend of his having the same problem. He thinks that guy had his water lines crossed or something. There was another guy at the lake that rerouted the lines and it fixed his problem. I’m just throwing options out there.

Sent from my iPhone using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 07:55:40 PM: Just double checked water lines, they’re routed correctly, also runs fine on the hose
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:00:58 PM: It’s a fuel thing. More load on the motor with the pump in the water. Check your float levels

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: eliminatorbuild on June 16, 2020, 08:03:06 PM: I wonder if you took a second water hose and sprayed the pump and exhaust tips with the boat running if that would make the boat stall out.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:10:26 PM: Also what rom is it idling at on the trailer and hose?

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:10:37 PM: Rpm

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 08:27:16 PM: It’s idling at around 1200 on the trailer, throttle response is super snappy and sounds mean as hell
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:29:18 PM: Ok idles fine then. Float check time. Crank it with the coil wire off for a few revolutions then check

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:32:49 PM: Also do you have flaps on your exhaust tips

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:43:12 PM: The only other thing I can think of is that the pump is putting more water pressure into the motor and you have a breach either in the intake manifold gasket or the head gasket.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 08:45:39 PM: Check the oil

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 427 wilder on June 16, 2020, 08:52:15 PM: When starting it on a hose in your driveway, is the pump running or do you disconnect the driveline?

You can stick a floor jack underneath the trailer hitch and jack it up in your driveway to simulate a launch ramp.

Sent from my iPhone using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 09:15:48 PM: Float levels are set correctly, it’s a quick Fuel carb and has the glass sights for the bowls, they’re adjusted to the center of the glass as specified, fuel pressure is 6.5psi on the rail while running.

I have the pump connected while running it on the trailer, but only because of the style of bellhousing I have and the bolts to the flex plate are Allen heads makes it basically impossible to disconnect without unbolting and jacking up the motor first, definitely sucks. But I don’t run it long that a few minutes at a time to keep from getting the pump real hot.

I don’t have flaps on the exhaust, never have though since I got the boat in 2002
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 09:21:24 PM: And what does the oil on the dip stick look like?

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 09:21:55 PM: Also it will start and run fine out of the water on the launch ramp on the angle, it’s only when it’s put in the water that the problem happens

The oil looks good still, if it were a bad enough breach that water was getting in the cylinders wouldn’t I be seeing steam? Had a water breach from a cracked manifold on another boat I had and was getting white steam pretty bad out of the exhaust, but the thing still ran great, it was a 460 though, might be different.
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 09:35:36 PM: Perplexing it is...

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 09:38:23 PM: Have you checked the carb nuts

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 16, 2020, 09:51:57 PM: I did think maybe there was a vacuum leak. I was using bolts for the carb before but replaced them with studs and nuts and did a vacuum leak check when I resealed the intake. I have caps on all the ports of the carb. It’s hard to believe it’s a load issue too because of how great it runs on the hose, and the fact it’s probably pushing close to 400hp
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 16, 2020, 10:01:38 PM: Hopefully someone pipes in. I can’t think of anything else

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: Bradbear12 on June 17, 2020, 05:49:21 AM: I had the same issue after I feshened up my motor and pump was super bummed in the driveway fine in the water fell on its face, my timing was off after doing some research with no vaccum advance you have to run between 28 and 32 degrees on the timing, this worked on my set up with a stock 454.

Sent from my SM-G965U using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 17, 2020, 07:12:33 AM: It did cross my mind that it could be a timing issue but it’s very odd that it would run fine out the water then not at all in the water because of timing being off, given that it doesn’t really have a huge load on it at idle.

I’ll walk you guys through exactly what happens:
I back the trailer in the water to just where back starts floating. I’ll leave to front still hooked up, I’ll start it up, it’ll idle normal for a few seconds, then like shit almost like it’s missing, if I try to give it gas, it’ll stutter and have a total lack of power, if I shut it off or if it dies, I won’t be able to get it started again until I pull it out (just to where it’s out) then after about a minute, it’ll start back up normally out of the water and run fine. If it’s hooked up on the hose at my house it also runs fine. It seems like through the exhaust tips or pump/intake grate being it the water causing a short to the 12v ignition wire, but the wiring is completely intact and that also just doesn’t make sense to me. :banghead: :banghead:
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 17, 2020, 08:16:00 AM: Where is your ground attached?

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 17, 2020, 08:22:06 AM: Here’s a thought, disconnect that choke and try it in the water...

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 76Mantra455 on June 17, 2020, 09:11:22 AM: Could it be the alternator grounding out the electrical? Is it a marine alt?

Sent from my LM-V405 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: FordLover on June 17, 2020, 09:51:13 AM: Just want to say it is super cool how you are all putting your heads together to figure this out. Very cool.

Jet boat community for the win!!!

Good luck figuring it out

Sent from my LG-TP450 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 17, 2020, 10:14:52 AM: I would do the Ford vs Chebby thing but I’ll wait till he fixes it.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 17, 2020, 11:47:45 AM: The ground cable from each battery has its own cable that attaches to the bell housing bolts, i suppose I can take off the alternator belt next time and see what happens, it’s not a marine alternator, but it’s virtually brand new. Oh and my choke is not wired lol it’s adjusted all the way open.
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 76Mantra455 on June 17, 2020, 12:14:58 PM: Quote from: throttlejunkie on June 17, 2020, 11:47:45 AM
The ground cable from each battery has its own cable that attaches to the bell housing bolts, i suppose I can take off the alternator belt next time and see what happens, it’s not a marine alternator, but it’s virtually brand new. Oh and my choke is not wired lol it’s adjusted all the way open.
Just un plug the alternator and then try it

Sent from my LM-V405 using SoCal Jet Boats mobile app (http://r.tapatalk.com/byo?rid=201)
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 17, 2020, 12:20:13 PM: Well we are narrowing it down at least.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 427 wilder on June 17, 2020, 01:18:56 PM: Is your feed point to the engine, the same from the hose as the pump?

When you rebuilt the engine did you change any of the coolant feeds?

Just wondering if some how you are back feeding water though the exhaust into the cylinders to cause it to shut down.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: mobboss on June 17, 2020, 01:45:09 PM: just for shits and giggles!! pull the distributor cap and look for a crack!! and that theres no water in there

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 19, 2020, 03:01:22 PM: Alright everybody, semi successful day out as we were able to actually run it on the water, the pump being freshly rebuilt with only one trip out since we rebuilt the motor seems to put a big load on it (also had an induced put in, maybe that’s why?) after starting it up and turning up the idle to around 2200 rpm out of the water on the launch ramp id be able to back into the water and it would stay running around 1200 rpm. So we putted it around in the marina at idle and checked timing, it was at about 19 degrees at 1200 rpm. If we tried to give it gas it would sputter and have no power, only after advancing it to around 36 degrees at 1200 or so rpm did it seem to run pretty damn good off idle, this of course means the total timing is something crazy Like 50 something degrees. And also the only way to start it back up after it’s turned off was to disconnected the batt wire from distributor, have my dad crank it, then plug the battery wire in. Any ideas why it would need so much time to run even decent in the water? It wouldn’t even stay running in the water at 16 Btdc. I does have a gnarlier cam than I originally thought and it’s got some big ass valves in the heads.
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 19, 2020, 03:29:50 PM: Too much timing. You’ll do damage if you keep it there and run it. Are we sure the distributor is in correctly?

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 19, 2020, 04:04:36 PM: Just got off the phone with my engine builder, old hot rod guy that owns a machine shop building dragsters, he told me the heads on my motor are like 62cc chambers and my compression is probably close to 12:1, I guess this motor is way more bitching than I originally thought. He told me those high compression motors love timing and around 50 degrees total isn’t going to hurt anything if it’s running good and not missing or pinging or anything. He said in a jet boat it’s not uncommon to have a lot of time, which sort of sounded weird to me. I know for sure the distributor is installed correctly and firing order ect. Is good
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 19, 2020, 04:10:30 PM: Well if you’re 12:1 I would highly advise using AV has or race gas. Pump gas will detonate your motor. Believe me I know

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 19, 2020, 04:23:21 PM: I’m still confused why you have to unplug the dizzy ground in order for it to refire.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 19, 2020, 04:58:38 PM: I’m running 91 octane in it now. I have to get it cranking first then give it spark or else I get starter kickback and hard start with that much timing
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: throttlejunkie on June 19, 2020, 05:00:10 PM: I’ll put 100 octane in it next time I take it out, does that octane booster stuff work? I still have like 1/2 tank of 91 in it now
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: angermgmt on June 19, 2020, 05:24:05 PM: I don’t use it.

Sent from my iPhone using SoCal Jet Boats
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 96Laveycraft21Xt on June 20, 2020, 10:57:16 AM: Quote from: throttlejunkie on June 19, 2020, 04:04:36 PM
Just got off the phone with my engine builder, old hot rod guy that owns a machine shop building dragsters, he told me the heads on my motor are like 62cc chambers and my compression is probably close to 12:1, I guess this motor is way more bitching than I originally thought. He told me those high compression motors love timing and around 50 degrees total isn’t going to hurt anything if it’s running good and not missing or pinging or anything. He said in a jet boat it’s not uncommon to have a lot of time, which sort of sounded weird to me. I know for sure the distributor is installed correctly and firing order ect. Is good

No offense here but you really need to be careful what you listen to with that guy!!

- if he built the engine he should know the exact compression ratio (maybe he gave you paperwork with it listed? )

- If he built a motor with 12:1 compression he should have told you to run race gas from the get go.

- No way on the 62cc chambers. he must have been in small block world. your 454 will be somewhere between 98cc and 122cc chamber size. What casting # are your heads?

- smaller chambers and higher compression typically takes less timing to achieve a proper burn so no, 50 degrees of timing will definitely hurt something. keep running it that way if you want to lose a piston.

- the fact that it is a jet has nothing to do with timing, the engine has no idea what its attached to. Yes, it is uncommon to have that much timing in any motor. thats why it sounded weird to you haha

i had my dominator jet rebuilt 2 years ago, made no difference in the idle adjustment. (i did not install an inducer though) i dont think the tight pump is an issue. a 1000rpm drop going into the water would be pushing your boat around like crazy, that would be a lot of pump pressure!

Keep hunting, you will find it.
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: 96Laveycraft21Xt on June 20, 2020, 11:06:15 AM: To rule out a short/wiring issue. disconnect all of the distributor wires and just run a positive jumper wire straight off the battery maybe and see if that helps
Title: Re: Runs fine on hose, won’t run in the water. HELP!
Post by: Flusher on June 30, 2020, 06:54:11 AM: The spark plug gap seems wide to me. I would try tightening it up to .032. The more cylinder pressure you have, the harder it is for the spark to jump the gap. The impeller doesn't put a tremendous amount of load on the engine, but it is a noticeable load, it may be enough to overcome the limits of your ignition.

Another thing you might investigate is the hot wire to your ignition. If it is small gage, corroded connectors, and an ignition switch that has seen better days... Try running a hot wire straight from the battery as a test.