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Post by ladrigan on Aug 22, 2019 19:44:10 GMT -5
360 pro sn 582510263
i've replaced the fuel line, pulse line, oil line, carb boot. Cleaned and Rebuilt the carb. except for the check valve. New dj6j sparky. ive got the low set for 1 turn, the high 1.5 turns, the idle all the way in. thats the only way i can get it to start and run. those dont sound right at all. if you open up the low it dies out, if you open up the high, it spits fuel from the carb and dies. the piston looks ok, thru the intake and exhaust side. gas cap has a new duckbill check valve in it
it does get gas and run, but if you let it idle, within 30 seconds it dies. compression is right around 120 to 130. The air gap is set to around .24. it starts fairly easy
any ideas on what it could be, i am ordering a check valve for the carb. not sure how to get that out yet.
Thanks Scott
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Post by undee70ss on Aug 22, 2019 20:06:24 GMT -5
Seldom does the check valve need replacing. Did you pressure test the carburetor? I suspect it’s not holding pressure.
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Post by undee70ss on Aug 22, 2019 20:11:09 GMT -5
Also what model carburetor do you have?
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Post by ladrigan on Aug 22, 2019 20:23:55 GMT -5
no i havent tested that, guess im going to have to buy a mityvac
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Post by ladrigan on Aug 22, 2019 20:51:31 GMT -5
i used a turkey injector syringe, a clamp and 2 pieces of fuel line and a bowl of water to pressure test it. its all i had laying around, use the injector to put fuel in carbs for testing, cut the pointy end off of course.
screwed the low and high ports all the way in. I put it under water and held my thumb on the plunger and tested the fuel in and pulse side, clamping off the the opposite side whilst doing so. no bubbles and the plunger didnt move. not scientific i know.
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Post by ladrigan on Aug 22, 2019 21:04:58 GMT -5
I checked something else, i added a connector to the end of the pulse line and added a longer hose and put it in a cup of water. no bubbles when i pulled the starter, what does that mean
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Post by ladrigan on Aug 22, 2019 21:06:58 GMT -5
walbro 2 21-146 on top 5- 458 on side
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Post by ladrigan on Aug 22, 2019 21:07:21 GMT -5
hdc 39
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Post by undee70ss on Aug 22, 2019 21:10:47 GMT -5
I checked something else, i added a connector to the end of the pulse line and added a longer hose and put it in a cup of water. no bubbles when i pulled the starter, what does that mean If piston was at BDC when test started, pulse line would have sucked in water. This could put water in crankcase (not good). |
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Post by undee70ss on Aug 22, 2019 21:12:24 GMT -5
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Post by ladrigan on Aug 22, 2019 21:13:23 GMT -5
it didnt do anything, but good tip. i put the line next to my face and didnt feel anything before i did the water thing
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Post by undee70ss on Aug 22, 2019 21:14:11 GMT -5
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Post by ladrigan on Sept 14, 2019 22:23:36 GMT -5
Ok, I bought a pressure tester for the carb. it holds pressure with no leaks. reinstalled the carb, it ill fire up and run as long as you hold the throttle in, the idle screw is all the way in. if you let go of the throttle it will die out in 30 seconds or less. picked a another carb, rebuilt it, pressure tested it, reinstalled, same thing happens. I tore it all down again. the only thing i can find is that the spring garter that goes around the boot isnt real tight. you can move it easily. ive changed the fuel line, pulse line, spark plug. it gets fuel when you throttle it up. it sounds good at higher rpms. the one thing i havent tried is using a different circuit disk gasket in the carb. I used one like what was in there. all the kits i bought, even the homelite kit came with 2 different gaskets, with only 1 difference between them that i could see. the one i didnt use has a little cut out zig zag and from what i can tell goes to the lo setting on the carb. on the one i used it just had a hole there. Am i using the wrong one? I think im going to try using the other gasket and puting an o ring over the boot and see if that makes any difference. im close to throwing in the towel on it.
thanks
Scott
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Post by 5terrysupersaws on Sept 14, 2019 22:55:23 GMT -5
Ok, I bought a pressure tester for the carb. it holds pressure with no leaks. reinstalled the carb, it ill fire up and run as long as you hold the throttle in, the idle screw is all the way in. if you let go of the throttle it will die out in 30 seconds or less. picked a another carb, rebuilt it, pressure tested it, reinstalled, same thing happens. I tore it all down again. the only thing i can find is that the spring garter that goes around the boot isnt real tight. you can move it easily. ive changed the fuel line, pulse line, spark plug. it gets fuel when you throttle it up. it sounds good at higher rpms. the one thing i havent tried is using a different circuit disk gasket in the carb. I used one like what was in there. all the kits i bought, even the homelite kit came with 2 different gaskets, with only 1 difference between them that i could see. the one i didnt use has a little cut out zig zag and from what i can tell goes to the lo setting on the carb. on the one i used it just had a hole there. Am i using the wrong one? I think im going to try using the other gasket and puting an o ring over the boot and see if that makes any difference. im close to throwing in the towel on it. thanks Scott Sounds like the incorrect circuit plate gasket was used, compare to the one in this video; www.youtube.com/watch?v=fcwTadYYiz8 |
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Post by ladrigan on Sept 15, 2019 11:43:13 GMT -5
Watched the video and it seemed to describe my problem. Changed out the circuit plate gasket to the other one. there are 2 holes in the circuit plate over the high and lo settings. wet the carb down with fuel and pressure checked it, it held pressure. Fueled it up, after about about 6 pulls it started. fuel is spraying out of the top of the carb, and smoked a great deal. it ran, carb adjustments had no effect, had to keep the throttle in to keep it running rough.
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Post by ladrigan on Sept 15, 2019 12:51:40 GMT -5
the carb gasket on the left has the opening for the lo side, the one on the right just has the hole. but there are holes on both circuit plates for the lo side that makes me think the one on the right is correct, which it had originally. or is the circuit plate wrong
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Post by undee70ss on Sept 15, 2019 13:04:27 GMT -5
First, I would set the air gap on module to .015. What is the condition of the boot below carburetor? Although I don’t think it’s your problem in this case, some HDC39 carburetors were defective.
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Post by undee70ss on Sept 15, 2019 13:05:29 GMT -5
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Post by ladrigan on Sept 15, 2019 13:57:18 GMT -5
air gap is set. the boot is new
the carbs original hdc39 dated 6/78 spare hdc39a dated 4/83 spare hdc39a dated 6/83
so the original may be defective but the other 2 should be fine
with whichever circuit gasket used in any of them, they all do the same thing
the boot garter was bad so i used a viton o ring to test it out. interestingly, i used a band castrator for goats to put it on with. that worked out and made it easy to install! I plan on tearing it all down again and trying again
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Post by undee70ss on Sept 15, 2019 14:06:40 GMT -5
Next step may be to pressure test the crankcase.
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