Carburetor trouble

jp1961

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Jul 22, 2013
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Hi Jerry,

You're testing the compression with the choke open, right? You have 20 more PSI than before, I wouldn't be too disappointed. You'll get her running.

The only top end restore I've done was on a 3hp Tanaka outboard. I replaced the piston and rings, but the cylinder jug is no longer available. I did lightly hone the cylinder with a 3 arm hone purchased at NAPA, actually designed for brake cylinders. It has about 103 PSI after the new piston and ring, but Mr. Brainiack here didn't do a compression test before, so I'm not sure how much (if anything) I helped the compression.

Regards

Jeff
 

viperv10

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Oct 7, 2016
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Oh the sweet smell of success and 2 stroke exhaust. Saturday evening after work I got back to it and put a new coil and spark plug in the old R7070.
After about 5 pulls it came back to life. I didn't let it run too long at 10:00 P.M. to upset the neighbors, but I shut it off and restarted it with one or two pulls.
That's a good sign. I also backed the little screw out a couple turns on the carburetor. I'll try to fine tune it tomorrow.
Jeff I don't think this carb really has a choke. It has a primer bulb and the throttle lever just above the air cleaner for low or high speed. No cables. A very simple engine. Thanks for you input.
Jerry
 

viperv10

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Hey guys , here is an interesting story I forgot to tell you. Last week I was talking to the guy I got this R7070 from. He said that when he first got it, it would run wide open and way too fast. He told me that he looked at the carburetor and said that there was no butterfly disc in it. He told me he had a different plastic carb and put it on. Well I told him that I know where that little disc went to. When I cracked the engine apart the other day, I found a piece of what looked to be a little brass tag or something inside the intake of the engine. I thought to myself, how did this get in here? So I told Darin that it must have come loose and got sucked into the engine. It was folded and bent up but now I can tell that that was what it is. It is hard to believe something that big could go through the reed valves and not damage them but they looked perfect. We both had a good laugh about it. I have noticed that some are held in with a little screw and some just slide into a little slot on the shaft held in with little notches. I could make out the little notches on the damaged throttle disc. Well I just wanted to share this odd story with you.
Jerry
 

Dixieboy

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Jul 19, 2017
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Love that little story, and yes the plastic carb throttle plates just clicked into place.
 
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