Distributer troubles

[BRTate]

Boat was very weak on hole shot, someone on here told me to see if I was hitting on all cylinders. While checking this I pulled off my dist. cap it was very gummed up and the rotor was very worn so I decided that was a good place to start. Replaced both today, swapped one wire at a time and have gone back and checked firing order multiple times now. Will not hit, just turns over. Used firing order 18436572. Gone back and checked all wires for loose connections. Have I missed a step, or am I just missing something simple. Messing up my 4th weekend, need help. Thanks

 

[putback]

Had a lot of experience w chevy small blocks, Don't understand what you mean by "gummed up dist cap"? Oil? exterior or interior? & worn rotor, how so? One gremlin these engines had was the distributor hold down would loosen over time allowing the distributor to rotate a few degrees. 1st usual symptom is low rpm power loss due to retarded timing. Also check to see if a spark plug wire fires a nice blue spark to ground when cranking over.

 

[BRTate]

Inside the cap had heavy build up on each point and the rotor was worn pretty good. Should I check for spark at plug or at dist cap or does it matter. The engine would crank right up before this. I'm at a loss on this one.

 

[putback]

This will be brief, site keeps dropping out. Common snafu we all make when changing wires and caps. One wire off at start meaning they're all off one. To check turn engine to top dead center on timing mark on crank shaft. Remove cap, is rotor pointed to the #1 cyl plug wire. If not its probably pointed at #8 or #2, you're off 1. Just move them around 18436572. HOWEVER, your cam & distributor makes TWO rotations for every ONE the crank shaft makes. This means you have a 50% chance of getting it wrong by 180 degrees on the distributor. So if your 1st check the rotor is pointing in the area of 180 degrees opposite from #1 cyl wire your crankshaft IS NOT at top dead center [piston is full down not full up]. Its really obvious and no problem. Solution is to rotate the crank shaft one revolution agian to 0 degrees on the timing marks. Definition of top dead center. Timing marks are at 0 degrees and # 1 piston is at top of cylinder. Oh, if you reposisition wires make sure you go 18436572 in the direction the rotor turns.

 

[putback]

If our boats ran like this site we'd all be swimming........................................

 

[Silvertip]

This will be brief, site keeps dropping out. Common snafu we all make when changing wires and caps. One wire off at start meaning they're all off one. To check turn engine to top dead center on timing mark on crank shaft. Remove cap, is rotor pointed to the #1 cyl plug wire. If not its probably pointed at #8 or #2, you're off 1. Just move them around 18436572. HOWEVER, your cam & distributor makes TWO rotations for every ONE the crank shaft makes. This means you have a 50% chance of getting it wrong by 180 degrees on the distributor. So if your 1st check the rotor is pointing in the area of 180 degrees opposite from #1 cyl wire your crankshaft IS NOT at top dead center [piston is full down not full up]. Its really obvious and no problem. Solution is to rotate the crank shaft one revolution agian to 0 degrees on the timing marks. Definition of top dead center. Timing marks are at 0 degrees and # 1 piston is at top of cylinder. Oh, if you reposisition wires make sure you go 18436572 in the direction the rotor turns.

Absolutely incorrect. The camshaft and distributor makes ONE revolution for every TWO crankshaft revolutions. If all you did was replace the cap and rotor there is no doubt you messed up the firing order and quite possibly by more than one position. When tracing plug wires, #1 cylinder is the front left plug on a small block Chevy. #1, 3, 5, and 7 on the left, #2, 4, 6, and 8 on the right. (Right and left are facing the same direction as the engine).

 

[Fishermark]

A couple of quick notes - Silvertip has it right that the distributor makes one turn for every two turns of the crank - but the point that putback makes is valid - your rotor either points at #1 at TDC or 180 degrees off.

But since you are going to check anyway, instead of TDC, go ahead and put the timing mark where it should be - probably around 8 degrees before top dead center and make sure the rotor is pointing at #1, and go clockwise from there.

Also, "left and right" can be confusing, so here's a picture that should help:

 

[BRTate]

Ok as Putback said I was off one, moved wires and Crunk right up. Went to the water and still no hole shot. I still have the same top end speed when I finally do plane out. The engine has no audible missing, and isn't running rough. It's just weak on hole shot. Also related or not I have a very strong gas smell in my exhaust. Left that out in my first post.

 

[Bondo]

Went to the water and still no hole shot. I still have the same top end speed when I finally do plane out. The engine has no audible missing, and isn't running rough. It's just weak on hole shot.

Ayuh,.... Is the boat new to you,..?? has it ever had Good performance for ya,..??

Has the fuel filter been changed,..?? was the contents of the old one checked for crud, 'n water,..??

Is the flame arrester Clean,..??

 

[BRTate]

Bondo, I have had the boat for 4 or 5 years now and it ran great when I bought it. I developed a little sputter and changed the fuel filter, I didn't check the contents. That was 2 summers ago, it has all gone downhill from there. The boat has never left me stranded, it just doesn't run like it did. Not sure on flame arrester, where would I find that?

 

[Fishermark]

....Not sure on flame arrester, where would I find that?

That is the "air cleaner" that sits on top of the carb.

 

[BRTate]

Ok. No the arrester isn't bad either.

 

[putback]

My apoligies to you, and thanks to Silvertip for picking it up. P Oed at site and didn't proof read. Thankfully my temper didn't cost you due to Silvertips catch. You should check the compression on all 8 cyls, when you do notice the condition of the plugs and which cly they came from. Lot of info to be gained there. Did you notice an increase or decrease in idle rpm when these symptoms begin? And yes gas smell in the exhaust means either to much fuel or its not burning the right amount properly.

 

[BRTate]

Ok, today I changed out all plugs. None were damaged, no single plug looked any different than the next. Headed to the lake in the morning, hoping for the best. Putback I didn't notice a change in idle speed. There could have been. This has been going on long enough now i don't remember. What would the reasons be if there were. Could the gas smell be a symptom of whatever is going on.

 

[achris]

You need to do a compression test. If the problem has been getting progressively worse, that could indicate things inside wearing like rings, and valve seats.

Chris.....

 

[Silvertip]

I didn't see where you actually checked ignition timing through all of this. Ignition timing can make a perfectly good engine perform in lazy fashion.

 

[BRTate]

Well we hit the water again today. As usual, with just me comes out of the hole fine runs great. Load up riders or try to pull skiers or tubes weak, weak. Had to move all weight to the front of the boat to get on plane and still took way to long. New distributer cap and rotor, new plugs, wires are good. I guess I am heading over to fuel issues now, or just a wore out engine. Achris, I will do a compression check this week maybe. Otherwise I am at a complete loss. Anyone have anything?

 

[BRTate]

Silver tip I have not checked timing. Put that on this weeks project list along with compression.

 

[NHGuy]

Fuel smell might be running rich...is the yellow tube from the fuel pump to the carburetor full of liquid? If so it will be rich. That's what happens when the main fuel pump diaphragm quits and you switch to the backup.
You also want to check your timing.

 

[BRTate]

NHguy I will add that to this weeks list. Since this is fuel injected will I have the same lines?