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Joined: Oct 2008
Posts: 43
Novice
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Trouble with carby, I changed all the O rings, engine ran ok but not on full throttle, suspect rich mixture. Added new fuel needle and daiphram, no go, throttle not moving freely, removed steel retainer on diaphram/popet valve, engine seems to run perfectly, suspect lack of lubrication, perhaps some sewing machine oil on cam, carby moving parts, etc. would have been a good idea, have other folks run these engines without the steel retainer on the diaphram in the carby? I have the poppet valve set at C, and removed a restrictor brass fitting, on the vacuum line from the carby to the flywheel, any ideas guys? happy new year, Cheers. 
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Joe Carroll
Unregistered
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I generally throw out the steel retainers on the poppetvalve, they cause more problems than they solve.
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Joined: Dec 1999
Posts: 5,384 Likes: 34
Repair Junkie
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I agree with Joe as soon as I see them I get ride of them too many problems over the years with them when you leave them in. 
Regards, ![[Linked Image]](https://www.outdoorking-forum.com.au/forum/images/members/mower-monsterw.jpg) Bruce Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.
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Joined: Feb 2011
Posts: 3
Novice
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A big hello to all.Happy to be aboard.I am a bit of a mower nut.I am new to the forum. I have a 160 cc Bronco Victa with the what now seems "infamous" plastic carbie.( They were metal in my day !)Who makes a carbie out of plastic ??? Same carbie troubles.Goes full boar,no rev range and won't idle."It seems someone could make a full time living on their own just fixing these blighters" A real engineering masterpeice it would seem.Please help. Many Thanks Fozz ...
Last edited by Fozz; 20/02/11 10:55 AM.
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Joined: Oct 2010
Posts: 1,819 Likes: 6
Junior Technician
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Fozz, i think you might be blaming the baker for something the milkman did.
High revs and no rev control usualy means there is an air leak somewhere. O-ring under the pull start on a power torque. Or the inlet O-ring on the manifold, or the one on the other end the carb seats on. Split broken or melted vacuum line to the decomp. Stuffed decomp (to check swap it out for an old spark plug) Hole rubbed through carb body under fuel tank, ditto with the rear cover. Of the diaphragm i nthe carb is not seated right.
And last of all, the bottom crank seal (bearing) is shagged.
If they can suck air anywhere, they run lean and rev to the moon.
I only throw out the steel bit if the carbs not working right. Generally thats if ive put one together from bits. 90% of them i just strip the carb, clean it all up and put it back together and its fine.
Most important thing to check is that the throttle cable gets you the full range of movement. On some of the cables the plastic bit up in the air cleaner can be screwed up and down the outer adjusting the length so you can get full throttle. If this is wrong you cant adjust it up in the air cleaner to get full song.
Bob.
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Joined: Mar 2011
Posts: 7
Novice
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Gomower,
How did you go with your carby problem? Did you solve it?
Definatly sounds like its sucking air somewhere after the carby. When you replace the inlet o'ring and the starter o'ring, put some oil on you finger and rub it around the o'ring before you install it, it will help it go in without any crimps, see it all the time.
Josh
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Joined: Oct 2010
Posts: 1,819 Likes: 6
Junior Technician
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For the starter you need the right O-ring too.'
The imperial ones are too thin.
Bob.
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Joined: Apr 2011
Posts: 6
Novice
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Hi mower nerds, I repaired my 2 stroke mower, I think its a v40 or Vortex. I replaced almost everything, all 'O' ring seals, carby intake manifold inner and outer seals. Crank-puller seal, bottom & top crankshaft bearing. Now the problem I am having is that its running too rich, too much fuel is going through the carby, drowning the motor. I positioned the white poppet valve on C pointing to the spray hole. Problem remains, tried it on A position, same problem. I compared two plastic carbs, one is off a mustang and the other is the standard that came with the mower. I put the mustang one with the black poppet that has no A,B,C postion marks on and it then made it worst pouring too much fuel into the motor. So I took it off and put the standard one on after cleaning it. I didn't mix up the carb body with the mustang one. The diaphragm seems working well... I put in new primer, floater and valve in the carby too. I can't think of anything else to replace. Why it is still pouring too much fuel through. I removed the air filter. It runs well at start up for 5 secs & then runs rough low idle at full throttle, when I turn off the fuel tap it runs smooth then revs high and stops which is normal. If I control the fuel flow with the fuel tap ,it runs smooth. What did I miss. I even have the Gregory's manual book with me. Hope you can help as will appreciate it really. I am a hearing impaired car mechanic and auto electrican and I do very well with team work. Am surprised with my self that I & workmates know nothing about victa plastic carbs. Here is a pic of the mower very similar to mine. Thanks ![[Linked Image]](https://www.outdoorking-forum.com.au/forum/uploads/usergals/2011/04/full-4905-872-victa.jpg)
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Joined: Oct 2010
Posts: 1,819 Likes: 6
Junior Technician
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Running rich???
Its a fixed jet. The poppet really does stuff all.
I have a rule with Victas. Well a couple.
No ethanol, not ever. That includes the crap unleaded from Shell. After 60 days tip the fuel in the car and mix up fresh stuff. Metal tins are out, 5L plastic containers are better.
If the engine is not running the fuel tap is off.
Im not sure what you are saying about how its running. Some of them do not appear to run the best when just at free rev. Start it, full song and shove it into some grass, how does it work then??? Ive had them running pretty rough, 4 stroking and what not but when you load them up they sound sweet and grunt into it perfectly. Thats what they are meant to do, be jetted right and run sweet under load.
It could be rich if the fuel level in the carb is too high. I assume you set that right, and got the right length needle. And put the needle in under the float the right way round, rounded end out. No air filter will make it run rich.
How it cuts grass is a lot more important than how it sounds and looks
Bob.
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Joined: Jan 2009
Posts: 6,926 Likes: 10
Pushrod Honda preferrer
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It is normal for cheap 2-strokes to run better at no load if you make them leaner, but then they won't pull much load.
There is something you didn't tell us about your substitution of the Mustang carburetor: how did it run on the Mustang (both before and after trying it on your Vortex)?
If you establish definitely that a good carburetor will make your mower run to your personal satisfaction, we should be able to get you there with your original carburetor, but you, and we, need to know that we aren't chasing a chimaera here. Getting your mower to run much better at no load can easily be achieved just by reducing the size of the main jet or lowering the float level, but then it won't mow grass.
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Joined: Apr 2011
Posts: 6
Novice
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Thanks for your fast reply Bob. I meant that It runs well at start up and fuel tap turned on for about 10 secs then it hunts for 2 mins then to very low idle at full throttle. I checked the cable and it moves the throttle inside the carby very well. It just pours too much fuel into the motor drowning it washing the lubrication off the piston which can damage it. I dont want to do any more damage. There was a full tank and ran down to 3/4 in just 5 minutes. I checked the needle and floater and seems to work well to me. The needle length is about 10.70mm and I rang my local mower if they have other types of needles and they said they didnt have as theres just one type of needle for all victa carbys. I dont know what else to do, I might just give up and look for another 3rd second hand carby and try it out later. Thanks Pro
Gregg
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Joined: Apr 2011
Posts: 6
Novice
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Thanks again to grumpy. I got the mustang one off ebay. It was worst pouring too much fuel into the motor with the mustang carby on the vortex so I removed it. How do you lower the level in the victa plastic carby. I cant seem find anything how to lower it. By Puting in a longer needle. I appreicate your help.
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Joe Carroll
Unregistered
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I would be making sure the needle and seat are sealing correctly, if you leave the fuel on and have it not running does fuel run out of the primer bulb?
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Joined: Apr 2011
Posts: 6
Novice
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No leaks Joe, It a brand new non geniue Primer, Floater and Needle. I have replaced almost everything. Oh well. Thanks for your wonderful help guys. Ill just try and find another one later on. Cheers
Rhino77
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Joined: Jan 2009
Posts: 6,926 Likes: 10
Pushrod Honda preferrer
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Rhino, just to clear up the question of flooding, can you do a simple test please. Fill the fuel tank, turn on the fuel, and walk away for 15 minutes. Then remove the spark plug and pull the starter cord a couple of times. Does liquid fuel come out of the spark plug hole? If it does, your problem is carburetor flooding. We can talk then about how to fix it.
Do not worry too much about piston damage from flooding with a mixed-fuel 2-stroke. There is always quite a bit of oil on the cylinder wall when you have flooding or when you over-prime it. (It's quite different with a 4-stroke: keep the priming to a minimum with those, because it washes the oil off the cylinder wall.)
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Joined: Apr 2011
Posts: 6
Novice
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Grumpy, Thanks for the tip, will get around to it this weekend & get back to all of ya this Monday.
PS I never pump the primer at all. I just turn it on and let it flow into the craby and it starts. Also will try replacing the top crankpuller seal again.
Thanks again guys.
Rhino
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Joined: Apr 2011
Posts: 6
Novice
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Hey guys I was told if I have replaced the Crank P/T starter seals that I did not know of. The one inside the Crank starter part. I don't know the name of that part. There is a big seal that sits on the motor housing AND tiny one inside the pin. I have checked the flooding and nothing came out of the spark plug hole. I replaced the fuel floater needle with the genuine needle (orange) instead of the after market needle (yellow) Will do run test it soon and get back to you if problem remains. Thanks for all of your help and tips guys!
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