OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Masport 2 stroke Iron horse

Hi Grumpy,
OK i have done all of the above.
The float needle is coming out when the float drops down and then reseals when up the float level seems OK very close to 15/16th".

The Engine however is still "Hunting" no matter where i adjust too.
as it is Hunting i have done tiny adjustments until its probably 2 more turns past the original 2 then it seems to stop.
Strange thing is the neighbors mower was doing hunting yesterday i was tempted to go and tell him what he needed to do but wasn't sure if he had a 2 or 4 stroke and whether its different for each.
I'm going to change the fuel/air mix needle to the one from the other carby. Reason is, is the original one when i cleaned it had some black stuff on it and when i was cleaning it i may have damaged it. I don't know grasping at straws now.

Anyway Mate if I don't hear back from you till after Xmas, Thank-you very much for all of your help and patience. And I would like to wish you and your family a very merry Xmas and A happy and healthy 2011.
1 month and 16 days we have been at this. I'll tell you this Grumpy I didn't know anything about small engines and now I'm fluent in just about all the parts, how to break down and reassemble, so if i never get her running at least Ive learnt a lot of stuff.
Take care
Pete

Compliments of the season to you and your family too, Pete. Trying the mixture adjustment needle from the other carburetor is worth a try - damaged mixture needles can be very difficult to adjust. If any metal has been removed from the tapered part, the "2 turns" rule won't apply. You might also check that no dirt or metal filings has found its way in between the mixture needle and the jet it partly obstructs. Sometimes when there is dirt involved, the mixture adjustment doesn't seem to work, until you adjust it way rich, then the engine suddenly becomes over-rich and you have to adjust the mixture back to where it was in the first place. If that happens, it means that whatever crud was obstructing it has been sucked past the restriction and has probably gone forever, into the engine. Unfortunately there may be more where that came from, so the whole cycle can repeat. It's very annoying.

If you still find small engines interesting now that you are getting the hang of them Pete, you may find yourself with a new hobby. It seems to happen to a lot of us.

Hunting happens with both two and four stroke engines if they have governors, and it always means either lean mixture, or the governor mechanism is a bit sticky. Bent links that bind at the ends where they pivot, can cause the same problem.

Hi Grumpy,
OK I changed the needle and it did make a difference but she is still Hunting. it was running for about 3 to 4 minutes (longest run so far )but then stopped and has only had short runs since.
remember i cleaned the whole carby out with carby cleaner so there shouldn't be any crud in there now. Should there ??.

I will ask one thing about when i cleaned the exhaust port holes if you remember 2 of the 3 holes were blocked but as i was carefully removing the stuff some fell into the piston hole. so when i finished cleaning i made sure i cleaned out the piston hole with carby cleaner. Is it possible for it to get to the carby from the piston hole ?(i would have thought not because it would either go back out the exhaust or out the spark plug hole. I did give her umpteen good pulls to blow out anything that might be left(with the plug out)
Pete

Pete, carburetor cleaner contains some pretty aggressive chemicals and was not a good thing to put into your cylinder. (Personally I wouldn't put it into a carburetor either.) It is possible for materials to get from the exhaust port back into the crankcase through the transfer port, but your Lawnboy engine has a reed intake valve, not a piston-controlled port. The reed valve is normally-closed (that is, it springs closed unless it is sucked open by incoming air/fuel mixture), so it should not pass anything back into the carburetor. It would take a lot of carburetor cleaner anyway, to slosh around in the crankcase enough to find its way to the reed valve. Long before that, it would have eaten your lower crankshaft-to-crankcase seal and made your engine run poorly, if at all. Did you ever check your crankshaft seals? This is normally done by putting each end of the crankshaft in turn in a vertical position, and trickling a bit of fuel onto the seal, while watching to see if it vanishes into the crankcase. Meanwhile having run the engine a bit since the horrible stuff went in there, chances are it has all been washed away by air/fuel mixture.

So far as crud in the carburetor is concerned, carburetor cleaner contains powerful solvents that should remove all the gum, oxidised oil, and any other sticky stuff. However it does not dissolve dirt or metal particles, which can sometimes lurk in the corners of drilled passages. The solids are normally removed in a second operation after using the cleaning agent: every passage is blown out with compressed air. This requires completely dismantling all kinds of tiny bits first, because otherwise the compressed air can destroy them.

I suggest you confirm that there is a lean mixture problem, by slightly choking the air intake. That will make the mixture as rich as you like. If the speed keeps cycling even when it is obviously running rich, you have a sticky governor, not lean mixture.

Hi Grumpy,
I suppose you must be wondering whats going on with the old Iron Horse.
Well I have been pottering away quietly and in the process i think i pulled the carby apart 6-8 times cleaned it adjusted the float, changed the needle and seat then changed it back,fiddled non stop under the flywheel with points, cant remember if i told you i got a second hand coil, got frustrated and left it alone over xmas had other stuff to attend to like buying xmas pressys and writing cards etc and putting on a kilo from eating to much pavlova and cream lol,spent 3 days in Hospital with breathing problems i'm ok now, then i saw a guy on Trade me(NZ site for buying and selling)who had a brand new champion J14J spark plug which you cant get anymore and swapped it with the one my idiotic local mower shop guy sold me a J19LM plug which i found out is for 4 strokes and a couple of primes and pulls of the cord and away she went no hunting, revs a bit high i think but that maybe because it's inside the laundry echoing(dont have a garage)so after nearly 3 months its alive.
so i would like to say a big thank you to you Grumpy and the other guys that chipped in with advice because in the end it paid off.
Thanks again
Take care, maybe now i know more about mowers i might be able to comment on someone else who is having problems, you never know
Cheers
Pete

That's great news Pete except for the breathing problems - you need to listen to some expert advice on that subject by the sound of it.

You are the second person in a week to report a defective new spark plug on this site. However I do not think that was a big part of your original problem because I recall that you could hold onto the plug lead while your daughter pulled the starter cord. If you could do that with the plug lead disconnected from the plug and your other hand touching the engine, the ignition system was totally ineffective at the time: the machine should have been producing about 15,000 volts and that is more than enough to spoil your day. However you've been over that mower and fixed several problems, so I hope there aren't any left now. Even if there are, you are fairly well placed to fix them after the experience you've had by now.

I'll close this thread Pete, but if anything goes wrong please start another one, and of course join in the fun when someone reports a problem that you can relate to. It's a pleasure to have someone with your consistent good humour and determination on the site.