1980 ss440 help!

1

14reamdalton

New member
Joined
Nov 16, 2014
Messages
4
Location
Findlay, Ohio
I have a 1980 SS440 that I just rebuilt, and it ran fine for the first few minutes I ran it, but then it seemed to want to bog and not do anything after that, just before I parked it, I held the throttle down and it just bogged and stayed the same speed. Tried to start it again this morning, but I cant keep it running, it will run about three cycles, then it will backfire and kill itself. I just ordered a service manual but was wondering if anyone else would know what is happening with it???
Thanks
 

Check the basics - spark, compression, and fuel. Why was it rebuilt, just time or was there a meltdown? I ask because I have seen debris from a meltdown in the crankcase and if not removed can take out a fresh rebuild.
 
when i got the sled, the fan side piston rings were rusted into the cylinder wall on one side of the piston, the other side was fine, I was able to hone out the cylinder a little to make it functional again, I looked in the case while rebuilding it and didnt see anything, I cleaned the carb out and rebuilt the fuel pump, took the oil injector to a local dealer and they said it was fine. I figured maybe its running too rich, but I don't know how lean to run the engine without it burning up the pistons. The original owner is a family friend and he had it rigged up for drag racing in the early eighties, i think he tried to set everything back to stock before selling it, but he never changed the main jet, i managed to find a stock one and put it in, but that didnt seem to change much.
 
The little bit it runs does it run on both cylinders? Is there fuel in the carb bowls? Spark look ok? If you've got good compression and spark looks ok dump about a teaspoon or so of premix down the throat of the carbs and see if it runs. If so maybe that rebuilt fuel pump isn't working good or just needs some priming. My summit after sitting all summer wouldn't start, same thing ran for a little bit then nothing. I dumped fuel down the carbs 3 times and the 3rd time it lit and stayed running.
 
Throttle over ride switch activating? That could be from a misadjusted throttle cable or sticking throttle. Instructions will be in the manual.
 
Might be a long shot but if it was sitting for some time, check for a mouse nest in the muffler.
They seemed to like the muffler on my SRV for some reason, they had a stash of sunflower seeds stowed in it one year.
 
After I got the engine built, I started it and let it run for about ten minutes, and it idled there with no problems, then I got on and took a couple laps around the yard with it, ran like a dream. I started it and ran it off and on the rest of the day and it got worse with each time I ran it. The next morning I decided to start it and put it back in the barn, but it wouldn't stay running like the night before, like I said, it would cycle about three times, then quit. I got it started about ten short times before I gave up on it and walked away. Both of the pistons still look really clean from what I can see and the plugs don't seem to be fouling out. I am thinking maybe the problem is in the carb or the fuel mixture being too rich....... Thank you for all of the suggestions by the way, they are very appreciated.
 
Also, I have been trying to mess with it off and on for about three years. I rebuild it the first year with a cheap set of pistons I got online. The next year it only ran one day and I noticed some grayish colored mist coming out of the muffler, so I took the heads off and the clutch side piston was black on top, I was told this means it is running rich on that side, but it is only a single carb engine. The next time it ran, I started across the field by my house with it and ended up shattering the fan side piston, It exploded from the bottom up (The head of the piston was still in perfect shape). All I can figure is that it blew because the pistons were cheap, I couldnt see anything else wrong with it
 
I would check the compression. If that checks out, I would then disassemble the bottom end and replace the crank seals. Running lean on one side of a single carb twin points me to the crank seals. Also I would check the piston clearance. If you shattered a piston skirt, your cylinders could be out of spec and need to be bored.
 
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cranks seals and piston clearance ..........the way you explain the way the piston burnt up was from too much clearance
 
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