# Just can’t get it perfect



## Marfmar (Aug 20, 2021)

So I am fixing up a side mount 8n here’s what I’ve done

New carb cheap Chinese but the old carb had the same issue 

New distributor, points cap rotor etc
Set the timing at 4 but have tried 
everything in the adjustment issue still occurs

new plugs

new gas

haven’t touched the valves , governer, or coil( it doesn’toverheat so I don’t think it’s this)

at idle and on decelloration the exhaust backfires but not violently like bad timing or incorrect fireing order like popcorn almost
On acceleration no issue at all


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## BigT (Sep 15, 2014)

Howdy Marfmar, welcome to the forum.

Do you have a strong Bluish-white spark? An orangish spark isn't good enough. 

I'm thinking that your timing gears may be worn enough whereby your timing is right for acceleration, but retarded too much when you back off???


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## Marfmar (Aug 20, 2021)

BigT said:


> Howdy Marfmar, welcome to the forum.
> 
> Do you have a strong Bluish-white spark? An orangish spark isn't good enough.
> 
> I'm thinking that your timing gears may be worn enough whereby your timing is right for acceleration, but retarded too much when you back off???


Haven’t checked the spark will do that after class , I read somebody else had a similar issue and it was cuz the distributor wasn’t grounding properly


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## SidecarFlip (Mar 25, 2021)

Considering it's age, I doubt if you will ever get it 'perfect'.


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## Joe.S.AK (Nov 26, 2020)

Marfmar,

"New carb cheap Chinese but the old carb had the same issue " which means that you probably should thoroughly clean and rebuild the old (MUCH better quality) carb when "things" settle down a little. Later take that shiny Aluminum Chineseium Carb, polish it up, mount it on a board and turn it into a lamp for the garage. I have one just like that :~) 

You mentioned all the things you replaced (hopefully one at a time) but you didn't mention spark plug wires. Forgot to mention you did it, perhaps? If you're replacing everything with Chineseium then .............

Simple things sometimes work - all fuel line fittings tight, not cracked and looking good? GOOD fuel flow from the tank to where the fuel line goes into the carb? No leaks, all filters clean, ? Good, solid BLUE 1/4"+ spark on every cylinder? All electrical connections clean, tight and without any sort-a marginal contacts? Plug wires and coil wire making good contact? Battery and it's ground to the frame OK? Key switch doing well?

Just a general look-over sometimes finds a really unexpected OOPS.

- Joe -


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## Marfmar (Aug 20, 2021)

Joe.S.AK said:


> Marfmar,
> 
> "New carb cheap Chinese but the old carb had the same issue " which means that you probably should thoroughly clean and rebuild the old (MUCH better quality) carb when "things" settle down a little. Later take that shiny Aluminum Chineseium Carb, polish it up, mount it on a board and turn it into a lamp for the garage. I have one just like that :~)
> 
> ...


It coul very well be the carb but I don’t think it is 
Spark is are orange so I think I need a coil
Wires are ford replacement and not dryroted but tried some of my mustang and no 
difference 
So I think it’s the coil is a weak and small orange spark


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## SidecarFlip (Mar 25, 2021)

Anything Chineseum is ALWAYS suspect. Bought a Chinese carb for my K241 Kohler and had to clean up the poor machining on it to get the float bowl to seal properly.

Your spark needs to be BLUE and sharp. I'd change the condenser first and make sure the connections are clean and tight and the points are flat and free of any metal transfer and CLEAN too.


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