help with ignition / carb

[mh11]

Hello 1978 galaxie 22xl with 350 chevy crate motor 100 hrs on it.

A gentleman that i met who taught auto shop for years says to get rid of the points ignition that I have, and put on HEI system off a chevy motor, and that I can get this from any pick and pull place.

Can I do this and be ok?

Also, said scrap the bad clogged up Q-jet I have on there, and put edelbrock carb on there. Which model is the Edelbrock that I need?

I am hoping these two things are going to get me back up around 4200-4600 rpms that you all have said is where I need to be.

Thanks!

 

[ziggy]

Re: help with ignition / carb

A gentleman that i met who taught auto shop for years says to get rid of the points ignition that I have, and put on HEI system off a chevy motor, and that I can get this from any pick and pull place.

Can I do this and be ok?

to me, that's just throwing parts at it. + that might not be the problem. and if your conversion don't go well, then you'll have the original issue + the conversion that's a problem. but you won't know which one to approach. besides. car parts don't belong on boats. most peripherals on a boat are marine rated by the uscg. car parts don't meet this rating.

R&Ring the carb. same thing. just throwing parts at it.

have you done any tune up work to this engine? like point's, plugs, condenser, cap, rotor, dwell and time it. have you checked compression. have you replaced fuel filters? these types of things. or go to the adults only sticky and find the one that says, can't reach wot. some things that cause you to not obtain wot aren't even mechanical in nature. like a dirty bottom of your boat.. there's a list there that's helpful.

 

[Maclin]

Re: help with ignition / carb

I am not sure of your symptoms, but don't do both things at once.

More random thoughts....

A points type ignition system that is set correctly will not limit your rpms, they are good to 5,000rpm or even more. Is electronic better? Usually, the dwell does not change and parts last way longer but your engine should run just fine on a points system that is in good working order.

Carbs can be unclogged, and a good old school mechanic can spruce up a QJ to be like new inside and out.

Maybe it became easier to teach than do after a while for the gentleman. It seems to me that fixing what you have is the best approach and should be the least expensive route as well.

 

[mkast]

Re: help with ignition / carb

Maybe it became easier to teach than do after a while for the gentleman. It seems to me that fixing what you have is the best approach and should be the least expensive route as well.

If the class in question is an auto technicians class, when was the last time a car was sold in this country with a carburator?
The only way you can run into a carburator in school is in a basic engine class usually at night. Then, only remove and replace (R&R).
That technology is a tad old.

 

[180shabah]

Re: help with ignition / carb

Tell that "gentleman" to keep away from your boat, and your wallet. He is going to cost you a fortune and possibly kill someone(suggesting auto distributer on maring engine, it will work but is not safe, boats go boom).

Rebuild your existing carb, you already know it is right for your engine and you have all the correct brackets, then do a full tune up. That "old" points type distributer will work just fine for you if it is set up properly.

Only got a few hundred spent and you don't have the headaches of "making it work".

Of course this assumes that the engine is still healthy, when was the last time it was compression/leakdown tested?

 

[mh11]

Re: help with ignition / carb

Well here goes, been to the sticky for WOT rpms.

Last thing I did was change the water seperating fuel filter. Tell me this, I took it off, it was full. Left it a week or so, and about a maybe 6 to 8 tablespoons of fuel poured out of it. Was the rest water that evaporated?

Then I changed the filter at the carb.

What about blowing out the anti-siphon valves? It seems if the boat comes out of the hole decent, that would mean they are not clogged, and the carb is getting enough fuel, would that stand to reason?

Took to lake, only pulled 3100 rpms and started backfiring, when I had it up around 3900 before. Got home, discovered a plug wire had fallen off. Guess that's an issue

Anyhoo, I already bought nice plug wires to replace the old crappy ones. Should I just buy a rebuilt q-jet, about 300 on ebay, they said they would put jets in for my altitude, and make sure timing is still correct?

I just had the ignition set to stock in October right before I winterized.

The boat comes out of the hole pretty good in my opinion, it just won't get past 3900 rpms without backfiring to me sound either valve problem or running lean, correct?

One more question, the exhaust bellows from the riser to Y pipe cracked, can I get that bellowsin there, without having to remove the riser? Seems it can be done, please let me know.

Thanks again for all of your help!

 

[dan t.]

Re: help with ignition / carb

first of all, the gm HEI is a great ignition system,but,it doesnt have the spark suppression system or screened venting nessasary for marine use,nor does it have the proper advance curve. these things can be overcome,but,only if you know exactly what you are doing. if you want to get rid of the points get a Pertronics conversion kit. stick with the q-jet, in my opinion it is the best carb out there,but,you need a good mechanic to overhaul it, some one over 50 who grew up with them,final thought, it sounds like you are leaning out at higher rpm check yte fuel pump volume and pressure.
good luck

 

[mh11]

Re: help with ignition / carb

Ok, so after the advice, basically I should buy the rebuild kit for the q-jet, or buy a rebuilt one, clean out the anti-siphon valves at both tanks, replace the fuel pump, put my new plug wires on, make sure ignition is still in spec, replace my cracked exhaust bellows at the riser, and take her to the lake to see if she will pull more rpms, would that be correct?

Then fine tune the jetting, on the secondary metering rods, correct?

Thanks again for all the help!

 

[fishrdan]

Re: help with ignition / carb

So, is the boat new to you, has it run at the proper WOT before, at the altitude you are running it at? You mentioned Reno, are you running at Tahoe or higher?

Yeah, it does seem like you have a lean/starved for fuel condition and need to go through the fuel delivery system, but it looks like you might be trying to "shotgun" it, fuel pump, carb, etc, etc.. Could be putting a lot of money and time into it when the problem could be something as simple as a split fuel line sucking air,,, not delivering enough fuel at high RPM.

You said you will need to do some carb tuning, so I assume you are at high altitude, do you need to re-prop for high altitude also?

 

[mh11]

Re: help with ignition / carb

The boat is new to me, came with 5 blade 23 pitch prop if I remember right. Pulled 3000 rpm, thats it.

Replaced with 3 blade prop
Got it to 3900 rpms, but it backfires full throttle up at those revs.

Don't know if it ever ran 4200-4600

I am running at 4000 ft to up at Tahoe.

I hope there is no split fuel line, as that would probably be big fire causing time, correct? Would I not smell fuel very strongly?

 

[fishrdan]

Re: help with ignition / carb

5 blade 23 pitch does seem pretty steep for your area and size of boat/engine. What's the pitch for the 3 blade prop and where were you running the boat with the 3 blade prop 4000 or 6200'. Sounds like you might need to do some prop tuning along with the fuel problem, but I'd get the engine running soundly before messing with props.

I did have a split fuel line that caused the same problem, that's why I pointed it out, though I'm not saying it's your problem. Mine didn't smell or leak since the split was at the highest point of the line (fuel tank high in bow) only symptom was hard starting at times and running carpy at high RPM. It was an easy fix that seemed like it could have been a lot of other expensive things, fuel pump, carb, etc...