engine will not reach speed

[boston_jake01]

I had some problems and I have fixed them thanks to this forum... I took the boat out today and got to test drive it in a lake when I accelerated<br />it did not reach more than 2700 RPM I don't know if the lack of trim tabs use (they are not working I need a pump) would be the reason I was never able to plane the boat out.<br />sorry the boat is a 1989 23' altura powerplay cuddy cruiser with a aq271c volvo penta and duoprop. <br />please help...<br />Thanks

 

[Don S]

Re: engine will not reach speed

Did you use the drive trim? If you have the drive trimmed all the way down, you will be pushing the bow of the boat down in the water. Trim it up a little at a time so the bow comes up and see if the rpms and speed picks up. When the speed starts going down and the rpms up, trim it back down just a bit. Trim tabs should only be used to level the boat side to side.

 

[boston_jake01]

Re: engine will not reach speed

I noticed that the secondaries on the carb don't open when i accelerate what could cause this it is a edelbrok it's not a marine carb.. and could this be a reason for not coming to speed. it does accelerate good when it's not in the water / under load.

 

[boston_jake01]

Re: engine will not reach speed

also when I was returning to the ramp I notice when I pressed the tilt button it seemed to increase speed not alot but alittle. I did it a few times to make sure it wasn't a coincidence and it did it every time.

 

[Haut Medoc]

Re: engine will not reach speed

If that carb. if not a marine rated carb., <br /> Get rid of it now & get the proper marine rated carb. for your engine! <br />You are playing with fire....<br />The wrong carb. can blow you to smithereens from unwanted vapors.....<br />Look in the search function under marine carb. & explosion & you will see what I mean....<br />I would not run it at all until it is replaced.....<br />Please heed the warning! ......JK

 

[Don S]

Re: engine will not reach speed

Once you get a proper marine carb on there, report back about how the rpm problem is doing. <br />My guess is the problem will be cured.<br />Not sure what intake manifold you have on there, but you also need to make sure the throttle plates on the new carb will clear the holes in your manifold.<br />The original carb for your engine was a Holley 4bbl.

 

[KRS]

Re: engine will not reach speed

Originally posted by boston_jake01:<br /> ..it does accelerate good when it's not in the water / under load.

That must be some prop!!! <br /><br />Seriously though, I wounldn't be throttling the boat unless it's under load in the water, otherwise ONLY idle or just above.

 

[boston_jake01]

Re: engine will not reach speed

ok

 

[boston_jake01]

Re: engine will not reach speed

I took the new carb (auto) out and put in the old one holley which I rebuilt and it really flooded. I was so pisst that I had to get away from the boat so I haven't had time to get back to it I will try looking at it tommorrow if the rain lets up, any ideas.....

 

[boston_jake01]

Re: engine will not reach speed

I have some other info on this problem, when I was returning back to the ramp I was just running at idle spped and when i pushed the trim button the engine speed icreased whether i pushed it to rise or lower. what could htis be and could this be a clue for the problem?

 

[ron7000]

Re: engine will not reach speed

the secondaries not opening IS your main cause of not getting over 3000 rpm.

If you know what the secondaries are, then hopefully you'll be able to tell whether they are mechanically actuated or vacuum actuated. If they're vacuum secondaries then it's probably the diaphram that controls them, if they're mechanical then look to see what's holding them up and also make sure when your throttle goes wide open that it's working the linkage at the carb all the way.
And before you even take the carb off, you can have someone manually open the secondaries and see if the motor takes off when you have the throttle down but are limited at ~3000 rpm. If it does then you know.

for the flooding holley, you said you rebuilt it. You probably have the float setting too high or have a bad needle & seat. With that carb off the engine, turn it upside down and blow into the port where the fuel line would attach. If you can blow in continuously or can hear air flowing thru the bowl then it's a bad needle & seat. If it doesn't then it's probably a too high a float setting, but it may also be a leaking or improperly installed power valve.

I don't know what you mean by trimming and engine speed, how fast were you going and how many rpms did the engine increase? I doubt this has anything to do with your current problem though.

 

[boston_jake01]

Re: engine will not reach speed

thanks for all that info, I have rebuilt the holley carb again ( I was just going to look inside then I broke one of the gaskets) I installed it on again and tryed to start her up, after numerous attemps I looked in the carb to see if there was gas coming out what I noticed is the there was tons of gas in the manifold and none coming out of the top jets... I'm not sure where the carb can leak from underneath so I'm lost could not installing the thick gasket under the carb do this I lost mine but did use two standard gaskets? In reply to the secondaries not working they are vacuum. I will chck the diaphram.
This boat is really starting to tick me off....
I would appreciate any and all advice
Thanks
Rich

 

[bjcsc]

Re: engine will not reach speed

The "thick gasket" is a riser that is supposed to help thermally isolate the carb from the manifold. I would think that you would want to replace it, but don't know what, if any, problems may arise without it. The rebuild kit should have had a new secondary diaphragm in it. If you are dumping that much fuel trying to start your secondary problems are just that - secondary. Did you install the new needles and seats from the kit? Did you check upside down as ron7000 suggested? Check the powervalve? A backfire can blow a powervalve. Boats run relatively low number powervalves. Mine is a 2.5 and I think that is the lowest you can get. In fact every carb. on every gas engine in 1997 (the only year for which I have a fuel system manual) uses a 2.5 with the exception of the 5.7GL which uses a 4.5. Check your spec. and make sure it hasn't been replaced it with a higher one by someone attempting to soup it up. The rebuild kit should have included a new powervalve, too. You only have two options: 1) Learn and check everything very carefully and be sure it is 100% correct or 2) Pay someone else to. Shop time for carb rebuilding at the VP dealer here is 3.5 hours ($315 labor)... may be able to post specs if you can post the Holley list number for your carb.( the number you ordered the kit with) What manual are you using to rebuild it / set it up?

 

[boston_jake01]

Re: engine will not reach speed

"Did you install the new needles and seats from the kit? Did you check upside down as ron7000 suggested? Check the powervalve? A backfire can blow a powervalve"
I did install the new needles and seats, I didn't check the foat level, and I don't know how to check the power valve I replaced it with the kit one, I got the kit from the auto parts store, is this a problem or are they the same?
the carb is a holley 4 barrel with dual feed single pump from a 1989 volvo penta gm 8 cyl. I will post the #'s off the carb tomorrow.
Thanks
Rich

 

[bjcsc]

Re: engine will not reach speed

Did you get a Holley marine kit? I don't know what the differences are but I know Holley makes marine kits as that's what I used. Someone here probably knows the difference from the auto kit if any but I don't.

You may have found your problem. You can check the old powervalve by sucking on it. If the rebuild kit you bought is not specifically for the exact carb. you have it is unlikely that the powervalve supplied is correct. Check the number on the new vs. the old.. I bet you'll find they are different. The powervalve supplies additional fuel to the main metering circuit at a certain level of manifold vacuum. That number is stamped on the valve and runs from 2.5 to 10.5 inHg.. Additionally, if the kit came with new jets and you used them it is also unlikely they are correct, too. The float level is unlikely to be the problem unless you bent something doing the rebuild which is also unlikely. Holley marine carb floats are correct if the bottom of the float is parallel to the bowl base when inverted, or held up (needle seated). They are adjusted by bending their linkage.

 

[boston_jake01]

Re: engine will not reach speed

ok here is the latest I removed the carb from the engine and found about 3-4 tablespoons of gas in the manifold.
I took the carb and flip it upside down and i was not able to blow so the floats are working. i checked the secondaries since it was off the engine, by taking the the diaphram case off the carb and appling vacuum to it and the rod raised and remained there as long as vacuum was applied, so that works. the butterfly valves also are not stuck. I cleaned out the gas in the manifold and replaced the carb I had my girlfriend turnit over while I watched with a flash light in the carb pimary and held it open to see where the gas was coming from I noticed that it was comin from the lower area, there are two little holes that are in the primaries tubes maybe it's coming from there? I didn't get a marine one. here are all the numbers on the carb. list 80158, 3457. on the choke butterfly 388. on the base 12R4608. 10911, 6R3385B
I don't know which one will help.
Please let me know where I can find the carb kit for this carb.
Rich

 

[bjcsc]

Re: engine will not reach speed

Were the gaskets in your kit blue and rubbery? If so, good as that's what's in the marine kit and you should be OK. Did you check your powervalve to see which one is in there? My fuel system manual does not list the specs for the Holley number you are reporting ( 80158 ). Not really a surprise as my manual is for '97 models. Maybe one of the VP techs here can post the specs for that one. However, your new powervalve should have the same number as the original.

If all this flooding occurs while cranking, there has to be a problem with the floats or the seat and needle, or mixture adjustment. How many turns out ( 1= 360') are your idle mixture screws? Count them as you screw them into the seat, don't screw them in hard, just lightly until they stop. Post your results. If you had the good float results upside down, the next thing to check would be the floats themselves. Hold them down in a mason jar of gasoline and make sure they don't leak. If that proves OK, check your fuel pump output pressure. Should be between 4.9 and 8.5 psi. at idle. No changes were made to the fuel pump, right? (meaning at some point in your ownership of this boat it ran fine as is) Although I have never experienced it, it seems possible that if your fuel pressure is too high it could force its way past the needle...

 

[boston_jake01]

Re: engine will not reach speed

Ok today I tryed it again and no change on the carb. so I removed it and replaced it with a quadrajet a friend gave me from his boat. I put it on and haray no flooding but, that was short lived it only ran about a minute at part throtle then when i returned the throttle to idle it stalled. I figured maybe the idle was set to low so I tryed again and this time i brought the throttle back slower and when it got around 1000 rpm it stalled this time I could not get it started again I checked for gas and spark and had both I'm not sure if the gas is shitty I drained the old gas and refilled it about 2 - 3 weeks ago I had replaced the feul water speporator should I replace this often since the boat was under water( it was in a storm in virginia before i got it ). I also did a compression test and it was good all around 150 psi to 160 psi. Something else I noticed today when I sterted the boat I turn the key to crank it and it wouldn't start until I let the key go not sure if this is always happening.
I continued try until the batteries died.
not a great day of progress....

 

[freddyray21]

Re: engine will not reach speed

Don't know on your boat, but on mine there is a wire running from the starter solenoid to the coil to give it more voltage when you are cranking the starter. Sounds like yours is off or has a break in it. If it stalls and dies at an idle your idle mixture screws are probably set wrong. If when restarting it starts like it is flooded they are probaly too rich. If not too lean. I run mine all the way in till they just stop then turn them out about 1.5 turns for a start.

 

[bjcsc]

Re: engine will not reach speed

boston_jake01: don't take this the wrong way, as I am only trying to help out, but no matter how many different non-adjusted carbs you try you are very unlikely to make a difference. I know how frustrating it is, everyone on this site does. Holleys are fantastic carburetors, the reason they are so popular is because each one can be set up many different ways. But they have to be set up right. They have to have the right choke setting, the right idle mixture adjustments, the right jets, the right powervalves, i.e. they are tuned to your engine. If you set yours up right, you can then eliminate it from your troubleshooting. If you don't start systematically eliminating systems you will be chasing your tail all summer.

What do you mean when you say the boat was under water? Do you mean the engine was submerged?