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dpcsar
08-05-2011, 07:16 PM
Hi all,

I have been reading through these forms and have found a lot of useful information. I am having a problem and could use some advice and next steps.

My motor will only idle... I can not get it to do anything else.

Here is the background and the things I have tried.

Background: I bought the boat with a bad block. I had a friend build me a new block, which is now a 393 (was a 351w). So it is a stroker now with a prized 1969 block and all the upgrades. We put everything in the boat and I guessed at the wiring, and got a few things wrong, so it didn't have spark. I took it to a shop and they got the spark back (new points and condenser). I still think there is a problem with the wiring and have found to wiring diagram on the form (one is for my boat year). It seem they did not connect a purple wire to the correct spot, so I am going to fix it tonight. I have a new coil, new solenoid, new plugs, new fuel pump and rebuilt carburetor.

What I have tried:
I have played with the timing. No real affect.
I have check the fuel pump by taking off the fuel line and seeing if it will pump. It does.
Of course I have tried the throttle. It still idle at full throttle (when warm, otherwise it dies).

So any help is appreciated! Any suggestions on things to try.

Here are my main questions.
1. Would putting a fuel bulb between the fuel filter and the fuel pump affect anything?
2. How would I know the carburetor is bad? (it was just rebuilt).
3. Are there any vacuum line to the carburetor? I don't remember any and don't know where I would connect them.

Thanks for the help,
Dwane

1redTA
08-05-2011, 08:01 PM
How does it idle? smooth rough what rpm
did you check the fuel pressure?
if you are using the spark arrestor is it clean?
what is the timing set to?
do a compression test in all the cylinders
what does the ballast look like? and get a petronix conversion with coil

j.mccreight@hotmail.com
08-05-2011, 08:28 PM
Fuel bulb won't do anything for you, no vacuum hoses to hook up, only hoses are for the pcv system.
Basic mechanics here, you need spark, compression, air and fuel to run. Sounds like you have all these, timing set at 10*, firing order 13726548 good compression and if you cant get the engine to come off idle but its runs then you have a fuel problem, verify all the basics , you need to check fuel pressure with a gauge and not by just looking to see fuel coming out of the line, carbs use a lot less fuel pressure than fuel injection iirc about 6-8 psi if this is good then most likely a faulty carburetor, btw what carburetor do you have on this engine

dtm
08-05-2011, 08:51 PM
Contaminated fuel? I've had bad fuel create a similiar condition in a 4 stroke motorcycle (XR 650L).

JimN
08-05-2011, 09:23 PM
[QUOTE=dpcsar;778406]Hi all,

I have been reading through these forms and have found a lot of useful information. I am having a problem and could use some advice and next steps.

My motor will only idle... I can not get it to do anything else.

Here is the background and the things I have tried.

Background: I bought the boat with a bad block. I had a friend build me a new block, which is now a 393 (was a 351w). So it is a stroker now with a prized 1969 block and all the upgrades. We put everything in the boat and I guessed at the wiring, and got a few things wrong, so it didn't have spark. I took it to a shop and they got the spark back (new points and condenser). I still think there is a problem with the wiring and have found to wiring diagram on the form (one is for my boat year). It seem they did not connect a purple wire to the correct spot, so I am going to fix it tonight. I have a new coil, new solenoid, new plugs, new fuel pump and rebuilt carburetor.

What I have tried:
I have played with the timing. No real affect.
I have check the fuel pump by taking off the fuel line and seeing if it will pump. It does.
Of course I have tried the throttle. It still idle at full throttle (when warm, otherwise it dies).

So any help is appreciated! Any suggestions on things to try.

Here are my main questions.
1. Would putting a fuel bulb between the fuel filter and the fuel pump affect anything?
2. How would I know the carburetor is bad? (it was just rebuilt).
3. Are there any vacuum line to the carburetor? I don't remember any and don't know where I would connect them.

Thanks for the help,
Dwane[/QUOThe

If you move the throttle lever manually, does the RPM increase? If it does, you may have a bad throttle cable.

dpcsar
08-06-2011, 02:41 AM
How does it idle? smooth rough what rpm
did you check the fuel pressure?
if you are using the spark arrestor is it clean?
what is the timing set to?
do a compression test in all the cylinders
what does the ballast look like? and get a petronix conversion with coil

I have not checked the fuel pressure yet. That will be the next thing to do.

The timing is not completely set. It is currently at 12*.

I will look into the petronix conversion with coil. It sound interest.

dpcsar
08-06-2011, 02:44 AM
Fuel bulb won't do anything for you, no vacuum hoses to hook up, only hoses are for the pcv system.
Basic mechanics here, you need spark, compression, air and fuel to run. Sounds like you have all these, timing set at 10*, firing order 13726548 good compression and if you cant get the engine to come off idle but its runs then you have a fuel problem, verify all the basics , you need to check fuel pressure with a gauge and not by just looking to see fuel coming out of the line, carbs use a lot less fuel pressure than fuel injection iirc about 6-8 psi if this is good then most likely a faulty carburetor, btw what carburetor do you have on this engine

Thanks for the help. I am running a holley 4160 that was rebuilt. I found a missing retainer pin and am going to fix it in the morning. I am not able to get it off idle. It take a little throttle to run and RPM doesn't change much. Checking the fuel pressure between the pump and carburetor in now on the list of things to check.

dpcsar
08-06-2011, 02:45 AM
Contaminated fuel? I've had bad fuel create a similiar condition in a 4 stroke motorcycle (XR 650L).

Can't be that. I clean and dried the tank. It has fresh fuel.

dpcsar
08-06-2011, 02:47 AM
[/QUOThe

If you move the throttle lever manually, does the RPM increase? If it does, you may have a bad throttle cable.[/QUOTE]

I have moved the throttle lever manually. It doesn't do a lot. I also check the to make sure the throttle cable was moving. Thanks for the idea.

dpcsar
08-06-2011, 02:50 AM
I got lucky tonight. The neighbor came over to check out my PS 190 as he just got done restoring a '85 stars and strips. He is a ford mechanic. We messed around and he thought the carburetor look fine and was getting enough gas. We pull the plugs and three of them were wet, so I got new plugs. No difference. So tomorrow I am off to buy a new cap and rotor and see if that will get the three cylinders firing. :) More tomorrow.

Kyle
08-06-2011, 03:06 AM
If 3 holes are bad check the wires too if the cap and rotor don't fix her.

Kyle
08-06-2011, 03:08 AM
Also if 3 holes were dead the idle could not be that smooth. Once you have all 8 holes firing you may want to re time it.

ahhudgins
08-06-2011, 10:01 AM
How did the engine run before your friend rebuilt it? I hope he got the timing chain in the correct position.
Plugs wet with gas or oil?

Others have already asked and it would help to know, does the engine idle smooth or is ruff?
You say you have gas at the carb, but when you pump the throttle at the carb, do you see a nice smooth stream of fuel coming out of the jet?

If you are doing cap and rotor, do the wires as well. And double check that you have the firing order correct.

Kyle
08-06-2011, 10:54 AM
You say you have gas at the carb, but when you pump the throttle at the carb, do you see a nice smooth stream of fuel coming out of the jet?



I'm dealing with the same issue on a rebuilt 4160 on a buddies boat. I had to send it back because when throttle was added there was a 1 second of no fuel and then it trickled and then sprayed. The spray should be nice as soon as the butterflies open.

Don't be cheap get some good wires too.

JimN
08-06-2011, 11:18 AM
I got lucky tonight. The neighbor came over to check out my PS 190 as he just got done restoring a '85 stars and strips. He is a ford mechanic. We messed around and he thought the carburetor look fine and was getting enough gas. We pull the plugs and three of them were wet, so I got new plugs. No difference. So tomorrow I am off to buy a new cap and rotor and see if that will get the three cylinders firing. :) More tomorrow.

After a rebuild, the compression and vacuum should have been checked. Also, if it has been cranked for any length of time, sniff the oil to find out if it has much gas in it. If it does, time it and verify spark with the fuel line disconnected and the throttle open so no gas can be drawn into the cylinders.

dpcsar
08-06-2011, 01:27 PM
Also if 3 holes were dead the idle could not be that smooth. Once you have all 8 holes firing you may want to re time it.

I don't know how to tell if it was smooth. I never heard it run before.

I got wire also. :)

dpcsar
08-06-2011, 01:29 PM
How did the engine run before your friend rebuilt it? I hope he got the timing chain in the correct position.
Plugs wet with gas or oil?

Others have already asked and it would help to know, does the engine idle smooth or is ruff?
You say you have gas at the carb, but when you pump the throttle at the carb, do you see a nice smooth stream of fuel coming out of the jet?

If you are doing cap and rotor, do the wires as well. And double check that you have the firing order correct.

There looks to be a good stream coming out. The plugs have gas on them.

I did get wires. :)

johnlanguab
08-06-2011, 03:21 PM
I would look into hot-spark.com for electronic conversion. It's cheaper than petronix ($59), and works great.

dpcsar
08-07-2011, 12:20 AM
Update. The rebuilder looked at the motor and check the compression. The values are out of adjustment. He had to guess at the adjustment. He wasn't able to start the motor because he didn't have all the items for a marine engine. Normally he does car engines.

Anyway, now that it will start and the new hydraulic lifter are pumped up, he can adjust them. This should solve the problem.

Thanks for all the help and I should be in the water next weekend.