Still having power issues - Round two

[Oaktown27]

I am back. I started with an overheating problem coupled with a no power problem. I did a tune up, rebuilt the hot riser on the exhaust, new impeller, and raw water valve to diver the cooling water. (thanks to everyone that helped me through that)

The engine starts right up, cooling water is flowing, the engine rev's easily and can be sustained up to 2800 RPM (or higher).

The reverse was not working, so I tightened the reverse clutch. I took it out, and in forward could only get the engine up to 1200-1300 RPM's. It was pushing me, but when I apply more throttle, there is no additional power. I feel like I am at 1/2 power. Tough when motoring into the wind.

I did pull the carb while troubleshooting my first problem. Cleaned it, including the jets. I just finished backing off the adjustments to the reverse clutch, thinking I might of over tightened this and this was the source of the problem.

Nope, still cannot get it over 1200-1300 RPM while in forward. Have looked over the other posts, and since the new riser has a new water inlet, this isn't the problem.

I have checked the advance springs during the tune up. I was thinking of pulling a plug to see if it was sooty, perhaps it is to rich? The only other thought is that the prop is fouled? The water is cold (SF BAY), so not anxious to try to check that.

Any ideas? I am at a loss.......

[joe_db]

1. Suffer the cold and check the prop
2. Check the firing order. If you swap the wrong two wires the engine is still relatively smooth but only has 1/2 the power.

[Dave Neptune]

Joe makes a couple of good points, do check the wires for proper order.

Whenever I have a power loss issue the first thing I check are the plugs. The power comes from the combustion in the cylinders and the plug color/condition can often give a clue as to where to start.

I bought a "Go-Pro" on a stick just for checking the bottom and prop of my boat. I could easily see if the diver was doing a good job or if anything was amiss re growth or something tangled in the prop.

What RPM's did you get before she lost power?

Dave Neptune

[edwardc]

… I took it out, and in forward could only get the engine up to 1200-1300 RPM's. It was pushing me, but when I apply more throttle, there is no additional power....

It is my understanding that unless you have an Indego prop, or a 2:1 reduction, this is not unusual for a direct-drive A4.

[joe_db]

It is my understanding that unless you have an Indego prop, or a 2:1 reduction, this is not unusual for a direct-drive A4.

It actually is pretty unusual. That equates to about 5-6 hp. I could get over 2,000 RPM with my old 2-blade and get at least 2400-2500 with my Indigo.

[Easy Rider]

Confirming what Joe says. My sweet spot for cruising is around 1750 rpm but could push 2000 for short bursts and that was with a two blade prop

[Oaktown27]

Thanks, I did check the plugs and the wires.

Wires are in the correct order. Wish it was as simple as that. Also, the plugs looked a little "sooty", so might think this is also a function of pushing the throttle without getting additional power. Thinking more fuel than it can handle.

Dave Neptune, funny thing is my wife said I should get a camera on a stick, and I replied no such thing, so I stand corrected. Thanks. Will look for a cheapy.

In the mean time, I am wondering if a weak spark could be a contributing factor. When I tuned it I replaced the usual, plugs, wires, condenser, Points.

The coil is probably original.

Think I should do this as a potential remedy?


Thanks.

[Dave Neptune]

Check the spark, if it is snappy and a crisp blue traveling 1/4 ~ 1/2" your fine, yellowish and "dusty" replace the coil. Do you have points or an EI ignition? If points it could be the gap or even dirty points. And while your checking give the rotor a twist to be sure the C-advance is functioning smoothly.

Also if you have points how old are they? It can also be a bad condenser giving a weak signal and thusly a poor burn.

Sooty plugs are indicative of an over rich condition. First look to the choke to be sure it is opening completely, an easy check.

Dave Neptune

[joe_db]

A fouled prop will produce the exact symptoms that you have - FYI.

[tenders]

A fouled prop will produce the exact symptoms that you have - FYI.

…and the situation happens so often that I would suggest definitively ruling it out before expending further mental energy on other possible causes! Seems like you’re not sure when the prop was last cleaned. That’s a symptom….

[Oaktown27]

All good advice, going to take a look at the prop and check the choke plate before I do anything else. Will let you all know the outcome.

[Jo Ross]

Similar issues

I'm having very similar issues as of yesterday so I'm anxious to hear if your solutions worked.

Started the engine after a two month sit and a berth shift (towed). Normal warmup with good coolant flow. Got it out into the channel and noticed I had a capped throttle response. Normally I can get very good RMP out of forward gear if I open the throttle. Wouldn't run it that hard for more than a few seconds but this time I had no further response out of the throttle. I forget the max RPMs I was getting but it was low. Eventually the engine started to overheat. I couldn't just sit in the channel with high winds so I ran it out and hoisted sail as soon as possible. Checked spark plugs and fuel filter while out and then just went for it on the inbound. By the time I was near my slip I had basically no power out of the engine and it was hot to the point where I think all of the coolant was steaming off before it made it to the exhaust.
Not super happy about that. I'm going to do some troubleshooting today but any update on your situation would be appreciate.

Cheers.

[joe_db]

Usually any bottom paint on the prop is removed by the time you motor a mile. If I let my boat sit for a month the prop absolutely would be foul.

* my buddy used special zinc prop paint. He launched, motored about a mile down the channel, discovered a bad leak, and turned around to haul back out. The zinc paint was gone

[Dave Neptune]

Jo Ross, sounds like you have two issues, over heating and lack of power.

The lack of water exiting the exhaust was probably due to "flow" causing the over heating not the heating evaporating the water. You will need to check the intake for flow and if it is clear then the pump, block restrictions etc..

The power loss could be many things. Since you pulled the plugs, what color were they. Were they white, sooty or an even brown? Fuel flow (pressure) can really be a big limiting factor as well as bad fuel. How long since your last tune up and what was done?

A dirty prop can really cause a loss of power and RPM's but should not cause a heating issue as with low power there is not much heat to dissipate and a hot engine can also loose power as it begins the seize .

Dave Neptune

[W2ET]

Have we done a thread on all the interesting things applied to props to keep them clean?

Bill