21.5 HP surging problem

Pochie

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I have a 2002 I/C Intex Platinum engine. I have to modulate the engine with the choke when running without the PTO engaged...it runs 99% and when I engage the PTO...she cuts at about 85% but I have to fool with choke on and off. I use seafoam in every tank of gas....Today I dismantled the carb....cleaned it with laquar thinner and put a pin through all the orifices I could find. I couldn't get the two screws loose on the bottom of the carb but did slosh lots of thinner in it. Actually got it back together, with the help of pictures I took while taking it apart. NO CHANGE in performance. My question: can the armatures (iginition coils) have any effect on the surging? There is a full gas flow to the carb. Any other ideas. I hate to buy a new carb ($300+) and then find out I should have checked other areas. Pochie
 

Mudface777

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Sounds like a fuel pump problem but first check that all the line fittings from the tank are tightly clamped. A loose hose will allow air into the system. Also check the impulse hose between the crankcase and pump for deterioration. It may also be a ignition coil problem when it gets to hot.
 

Rivets

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You don't give us engine numbers so I am guessing here with a couple of suggestions. When you had the carb apart, did you notice if the float needle was solid metal, or had a viton tip. If it was solid I think the viton seat may have swelled, not allowing enough fuel to enter the bowl before shutting off. If that is the case, I would recommend that you disassemble the carb and replace the float needle and seat. If you do this, I can provide you with a step by step procedure. Another possibility is that the float level is set to low and again you are not getting enough fuel in the bowl.
 

Mudface777

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Yea I would listen to Rivets. He has the experience.
 

Pochie

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You don't give us engine numbers so I am guessing here with a couple of suggestions. When you had the carb apart, did you notice if the float needle was solid metal, or had a viton tip. If it was solid I think the viton seat may have swelled, not allowing enough fuel to enter the bowl before shutting off. If that is the case, I would recommend that you disassemble the carb and replace the float needle and seat. If you do this, I can provide you with a step by step procedure. Another possibility is that the float level is set to low and again you are not getting enough fuel in the bowl.

Hi Rivets. I ran the engine a moment with the fuel hose off the carb and plenty of gas poured out, so I don't think it is a fuel pump.The tractor model#: 917.272452. The engine model number: 445777, Type #: 0154-E1. The surging starts immediately upon start up and runs the same whether it has run 1 minute or 30 minutes. I couldn't get the float bowl plate off. The 2 screws were TOO tight and I used all my might and the screws were then rounding out. Being unfamiliar with the carb, I didn't try to unscrew the nut at the bottom end which might be a fuel solenoid as per the small pictures as I didn't know if a spring would pop out. My other question: this just started happening few days ago. After running the mower 20 minutes or so, it abruptly shuts off, which makes me suspect a separate issue that I need new armatures. When these armatures wear out, do you need new ones or can you somehow repair them? Any new ideas appreciated. I will then dismantle again and then get back to you.
 

Rivets

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Sorry, but you may not like my advice. With the carb on your engine, I would stop now and have it rebuilt by a good repair shop. That is one of the more difficult carbs to work on and unless you feel really qualified, I would look in a different direction to solve the problem.
 

Pochie

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Hi. Advice noted and appreciated. I am a 'tinkerer' and think I'll fool with taking the bottom of the carb off, as I think I can do it without removing the entire carb. If no luck, I'll then call some lawnmower shops. I figure I can't really hurt it and they can replace any parts. Thanks and have a good day.
 

ILENGINE

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Just don't mess around with it too much, and then take it to the repair shop. Nothing pisses off a tech more than customers screwing up stuff before the fact. I have even gotten a 5hp briggs in the shop a few years ago in a box with the valves, piston, flywheel, crankshaft removed. Guy said it wouldn't run. I had to reassembly the engine to find out the guy had a bad spark plug.

Just remember that a good techs time is worth over $1 a minute, and can really add up if the tech has to figure out what you did to get to this point.
 

Pochie

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Hello and I appreciate your advice . The more I read re these carbs being complicated I decided to buy a new one from Sears for $124.00. I figure a repair shop would want close to that. I'll get back on after I get her on and try her out. Thanks again.
 

Pochie

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Just don't mess around with it too much, and then take it to the repair shop. Nothing pisses off a tech more than customers screwing up stuff before the fact. I have even gotten a 5hp briggs in the shop a few years ago in a box with the valves, piston, flywheel, crankshaft removed. Guy said it wouldn't run. I had to reassembly the engine to find out the guy had a bad spark plug.

Just remember that a good techs time is worth over $1 a minute, and can really add up if the tech has to figure out what you did to get to this point.
Hi. I have a question for you: My 21.5 hp is a twin cylinder. The two magnetos..are they the same on both sides? They look to fit on either side. I am going to buy 2 new ones and there is only one part # listed so I am assuming they work on either side, but would appreciate your opinion. Thank you.
 
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