b20 AQ130 stalling when warm **Now With Pics & Vids**

[Grizzlybear]

Had the problem for a while now.

Basically stalls after about an hour of use, then wont start again for about 20 mins. Renovated the double overhead Solex carbs this winter, problem persists. I have read a fair bit on here and deduced the following:

# Heat causing ignition coil/cables to fail
# Heat causing fuel line to get screwed up
# Rubbish in the fuel
# Poorly ventilated fuel tank
# Condenser not working properly

Gonna work though those one by one, but if anyone has anything to add to CSI Penta, they are more than welcome.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Just want to update.

Vapour lock. If I am getting vapour lock will the carbs be completely empty? As when I checked after stalling they were full of fuel and when I pumped the throttle while trying to restart, fuel dropped down into the carbs. Some white smoke popped up from the carbs when this happened.

I checked the plugs too and they were bone dry, no sign of flooding. I filled the chamber with start gas and turned it over again, nothing. And then after 20 mins cooling down she springs into life. I just want to rule out vapour lock.

If anyone could elaborate a little more on vapour lock I would be much obliged.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Hmmm I can see penta's are not iboats motor of choice

 

[captmello]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Hmmm I can see penta's are not iboats motor of choice

Speak for yourself.

If the vent is clogged, simply loosening the gas cap should relieve the vapor lock.

Feel the coil when it dies to see if it is overheating.

Next time it dies, check for spark. Try to narrow it down a bit. Bring a spare plug with you, remember it needs to be grounded the fire.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

*Haha thanks Capt!

Testing the plug, you just disconnect, reapply the HT and hold it near metal no?

 

[PiratePast40]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Hmmm I can see penta's are not iboats motor of choice

Griz, you haven't really been asking many questions, just pointing out your proposed course of action. Like the Captn' is tellling you, perform tests to verify your suspicions of each area and then either eliminate that as a problem or go deeper to resolve it.

If you think it may be a fuel issue, you can dig deeper into that as well by using a portable can to identify posssible issues with the anti-syphon valve, junk in the tank clogging the pickup, water in the fuel, improper vent, degraded fuel lines, or a bad fuel pump.

Also let us know if this boat has run successfully in the past, if this is a new problem, or if the boat has been sitting for years.

You're right in that it could be any of the issues you first mentioned but you'll need to be specific about what has or has not been resolved and why you think that. The "Adults Only" section http://forums.iboats.com/showthread.php?t=468285 has a ton of information on how to test systems and can give you a good idea of what to look for.

I think the issue of a bad coil is a good place to start but until you start actually testing, there is no way to know about any specific system.

Edit - your on the right track with testing a plug by seeing if you can get a spark to jump across the gap. Might want to hold it with an pair of insulated pliers though. Getting "bit" by a spark plug is an experience you won't soon forget! You can also measure the resistance of the coil when it's hot to see if it's shorted out or open after it gets heated up. I don''t remember the numbers but if you google "testing a coil", you'll find out how to do it properly.

Good luck and let us know how things are progressing.

 

[PiratePast40]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Another suggestion regarding your observation when pumping the throttle after the engine has quit: The accelerator pump discharge squirts out of the "candy cane" at the top of the carb (emulsifier jet). The chamber is fed from the main fuel bowl. If you weren't getting any gas to the carb, you would have a limited supply available to the accelerator pump, i.e., limited to that fuel still in the accelerator pump chamber. If you're only getting 1 or 2 squirts, it's a good possibility that you aren't getting fuel to the carb for some reason.

A few other things to consider, if the rubber components of the fuel system are 35+ years old, there's a good chance they have deteriorated. Again, using a portable fuel tank and bypassing the installed system will tell you quite a bit and help isolate or rule out that part of the fuel system. You might want to pull the strainer out of the fuel pump to see if it's clogged although I would think that's either a go or no-go as far as the boat running at all.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Great guys. thanks for the answer. Yup gonna be a boat load of trial and error on this one. For the record the boat has always had this problem the whole time I have had it. The ignition coil just gave out on me last year, so I have replaced that, but still could be getting too hot.

I have an outboard tank can I prob port into the motor bypassing the main tank. I am hoping that will give me straight answer on the fuel. The fuel line, which I am told is a bit of penta b20 flaw runs right along the block. It's no great leap of faith to imagine the fuel cooking off in there. but the full chambers on the carbs is suggesting otherwise, but they could be partially full, i wouldn't know. So even if it dies with the outboard tank, I will poor fuel into the cards (cold fuel) and check that way.

Plus, gonna run it with the fan on, see if that makes any difference.

Will come with results after the weekend.

 

[PiratePast40]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

I haven't heard people complaining about vapor lock with this engine. Doesn't mean that it doesn't happen - just haven't heard about it. The engine temp shouldn't routinely run much over 160*F and the doghouse temp shouldn't be too bad. At least mine isn't. Also wouldn't think that running trhe bilge blower would have any affect either but if you're thinking it does, wouldn't hurt to check.

I'd be setting the multimeter up with clips for checking the coil primary and secondary sides after the engine quits to find out one way or the other. It's a pain in the rear to get back there on your hands and knees with the boat rocking but it's the only way I know of to check the coil. You might also go through and check voltages at the distributer with the key in the start position and at the run position to see if the resister is still in good shape. With a resister in the circuit, you DO NOT want a coil with built in resistance. Again, go through the points ignition troubleshooting section for some excellent pointers.

Might want to check the points to see if they're burnt or have buildup on either side. It doesn't sound like the condenser is the issue but might as well find out for sure. I believe that if it was the condenser, the engine would run rough or not at all. Sounds a little funny but take a look to see if there is a hole burnt in the side of the condenser as well. If you need a new one, I'm getting the impression that those are matched to the coil so you should be able to bypass the $27 and $50 OEM ones if you can find others with the pigtail to match your coil location.

Of course, new plug wires, cap, rotor, and points are allways a good idea if yours are of unknown age. You can use automotive for the wires and it's even better if you can find a shorter coil wire as the automotive version is quite long.

Good luck. I know how frustrating these problems can be.

 

[captmello]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

I'm thinking the resistor wire, or ballast resistor is by passed/bad causing the coil to overheat. It may have been wired improperly by the previous owner. Do you have points or electronic ignition?

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

Yup this is where I confess grotesque ignorance. I don't know if it's points or electronic (ignition), I am guessing points as the entire boat is from 64'. Guys thanks so much for your help.

it was points**

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm

Re: b20 AQ130 stalling when warm

I am based in Sweden, and here every other boat is a b20/b18 and while i noticed vapour lock is not a problem generally asked about tin the states, it seems more prevalent here.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

A long evening at the boat. Took it out for a long run this evening. Installed a small coupe fan in the engine compartment just to try and cool down the electronics.

Checked the tank ventilation and lines, all seems well.

It stalled again, but it seems to be a little more stable in the sense that you can return it to idle, but when you try and push it into gear (normally reverse) it stalls.

Same story, it wont start for 20+ mins. Anyways. As you can see we got a spark (kinda funny)

And this is the state of the plug, immediately after stall:

Note: the plug was very white and very hot. I mean, it feels like it's flooding due to the non start afterwards, but that plug is is bone dry. I think the plugs look in bad shape, they have only had maybe max 20 hours running time.

We also got white smoke rising up from the carb when we pushed fuel in.

Any ideas?

 

[captmello]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

I'm not sure, that plug looks okay. Did you try any other tests? loosen the fuel cap? pour a little fuel into the carb perhaps. I'm guessing its a fuel delivery issue. I would go through the fuel system. Its old it may be clogged/rotted.

Did it start when you put fuel in?

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

We focused just on electrics/ignition this evening. Gonna go back tomorrow evening to mess around with fuel and carbs. So we should just pour fuel into the carb when it dies? Sorry to sound silly but like how much? I don't know if it is being blocked, as the fuel is still dropping down into the carbs when you push the throttle forward, maybe it's just dropping enough to kill the engine. Would a lean/rick fuel mix do it?

 

[captmello]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Not much gas, maybe 1/8 cup, 30ml in each carb.

If it is running out of gas, it will lean out the engine as it is stalling.

The fuel should spray, more than drop when the accelerator pump is pumping.

This still doesn't explain why it takes 20 minutes to get fuel again. this is why I think it is a clogged vent line.
Next time it quits, open the gas cap and see if it sucks in air when you do. I would do this before pouring gas into the carb.

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Yeah the quitting for 20 mins after stalling is what is confusing the hell out me. As it it was a fuel shortage, then just pouring gas in should solve it. Gonna run it with an outboard tank, see if that changes.

 

[captmello]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

if the breather hose is pinched or collapsed, 20 min could be enough time for the air to slowly leak past.

I liked the spark tester you used in the first video. was that you or your buddy who felt the test?

 

[Grizzlybear]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

I held it, my buddy took care of the laughter.

**one thing is that it really is running nicely at top revs and crusing around. Would a pinched fuel line not cause problems all round instead of just at idle and gear engagement?

 

[captmello]

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Re: b20 AQ130 stalling when warm **Now with pics and vids**

Well, it was funny. I think you're close to figuring out your problem.