Intermittent Start - Starflite 75

[wdirnbeck]

Evening all,

I am at the end of my line here. My 1961 Starflite 3 75HP (with unicharger) has been having some issues getting started and running well. It was a boat anchor when I got it from some ol' boys' barn last summer and ended up tearing it all the way down to the powerhead for the next several months. I got the engine freed and cleaned up the guts really well. New rings, honed cylinders, wiring harness, etc. I was throwing parts at it because pretty much everything was f'd.

It never did run well at the end of my time rebuilding last summer and the best I achieved was 2 moments where it started up and ran for all of 1 minute cumulative in a barrel. Compression is 80 PSI in all cylinders which seemed low but since it had fired off for me I went with it. Fast forward to this summer and all signs point to fuel delivery issues. I have spark, the timing is right on, and there is some level of compression so I went into the carb again and really got in that sucker. I took the boat out to the lake today and backed down a desolate ramp to try and test the engine with no luck getting the engine to start. I pulled the boat up getting ready to give up and for the hell of it tried to start it out of the water on level ground and it fired off and ran! I let it go and it did not seem to want to die so I shut it off, put my boat all the way in, and then...nothing. It wouldn't start back up. I was thinking maybe it just wouldn't start at an angle since I had it on the ramp while trying to get it to start up.

Does this still sound like a fuel delivery issue? The engine definitely leaves its telltale mark with the lovely rainbow in the water. Or am I just getting lucky starts due to low compression?

 

[racerone]

You might need a new impeller now.-----Is the belt timing correct?

 

[jimmbo]

Are you advancing the Throttle off idle when trying to start in the Water?

 

[F_R]

Belt timing was my first thought. But certainly not my only thought. On that note, carb would be very low on the list unless you are flooding the daylights out of it.

 

[jimmbo]

Those engines are quite Tolerant of Flooding, they burn about the same amount of Gas at Idle as they do at WOT

 

[F_R]

Speaking of carbs, that hot water automatic choke never won many prizes in my opinion. Use the manual choke-on, choke-off feature at least till you get everything set up correctly..

 

[wdirnbeck]

Are you advancing the Throttle off idle when trying to start in the Water?

I feel like I tried every throttle position when attempting to start it.

 

[wdirnbeck]

Belt timing was my first thought. But certainly not my only thought. On that note, carb would be very low on the list unless you are flooding the daylights out of it.

If I followed the manual right the timing should be right, flywheel boss aligned with boss on the top of the powerhead where the water cover is, then the notch on the distributor pulley aligned with the mark on the unit that holds the distributor. I couldn’t find any info about it anywhere but I set the timing with no advance.

 

[jimmbo]

I am going to assume because you said Unicharger, it has the Battery Ignition

 

[wdirnbeck]

I am going to assume because you said Unicharger, it has the Battery Ignition
View attachment 381869View attachment 381870

Yes, it does.

 

[racerone]

Correct the unicharger has the battery ignition.----Weak spark is the major reason for hard to start issues.----So does spark jump a gap of 5/16" or more on 4 leads ?

 

[wdirnbeck]

Correct the unicharger has the battery ignition.----Weak spark is the major reason for hard to start issues.----So does spark jump a gap of 5/16" or more on 4 leads ?

I’ll check tomorrow. My spark plug wires aren’t solid core and are the carbon core type which were fabricobbled together last year from some I had lying around from another project. I was able to remove the screw terminals from the old chewed up original spark plug wires and re crimp them onto the carbon core ones. I read somewhere that these types of leads may also have enough resistance to lead to a shorting condition within the distributor or from the spark plug wires to the block. So if the spark jumps a 5/16” gap I’ll replace those wires with metal ones before I look at the ignition coil.

 

[racerone]

Install wire core sparkplug wires first.

 

[oldboat1]

Wire core, then test ignition strength with one of these spark testers:

 

[wdirnbeck]

Install wire core sparkplug wires first.

Would you happen to know a good source for these?

I found these that look like they’d work, I guess I can deal with the blue clashing with my fire engine red block haha.

Sierra 18-5229-9-1 Wiring Plug Set (5Pk)

Sierra 18-5229-9-1 Wiring Plug Set (5Pk) available at Wholesale Marine. We offer Sierra Marine products at lowest prices with superior service.

www.wholesalemarine.com

 

[Crosbyman]

I have used similar ones on my oldies and they work fine.

 

[wdirnbeck]

I have used similar ones on my oldies and they work fine.

Are you saying you’ve used the carbon core wires or are you referencing the set of wires I sent in the link?

 

[racerone]

Carbon core wires on your motor is a mistake.

 

[Crosbyman]

Are you saying you’ve used the carbon core wires or are you referencing the set of wires I sent in the link?

always use solid wire ... never carbon

 

[wdirnbeck]

Correct the unicharger has the battery ignition.----Weak spark is the major reason for hard to start issues.----So does spark jump a gap of 5/16" or more on 4 leads ?

Tested this evening, the spark does indeed jump a 5/16" gap. It also now has metal core wires, I bought the ones I posted earlier in the thread. Checked compression with a different gauge and this one is reading 70psi on all cylinders, 10 psi less than what the other gauge told me. Also gapped sparkplugs to .030.

I double-checked the timing and everything seemed in order if I did it all properly. Lined up the flywheel and engine block mark, then the distributor pulley mark, distributor housing mark, and bracket mark. The test light from ground to the insulated side of the breaker point was on so I backed it off to the point where the light just went out, then rotated the flywheel so the pulley was at the next mark at 90 degrees then did the same for the other set of points, then gapped at .020. Every once and a while I get a shudder or what sounds like a single cylinder firing but most of the time it's just cranking, not wanting to start at all.