carburetor help on a fd620

[Bazooo guy]

Thanks John
That's the info we should be giving to someone who admits he is not "mechanically inclined".
If we look back at the original post he obviously had the carb off. That being said I wonder if the springs and rods were assembled properly. I know on most small engines there are multiple holes for the rods and springs and if the governor is hooked up incorrectly it can cause the problem he is experiencing. Now for someone to tell him over the phone that he needs a new fuel pump sounds crazy. I hate to replace parts without confirming the part is not functioning as it should. Diagnostics is not replace with universal parts cause you could end up with more problems than you started with.Lets look at the easy fix before we send him to the parts store for parts that nobody is sure he needs. Does anyone have a diagram of the carb and governor linkage? It could be as simple as moving a spring

http://www.smallenginesuppliers.com/shop/html/governor_adjustment.html

[Bazooo guy]

Ok Nick is this what you are working on?

http://www.smallenginewarehouse.com/images/manuals/FD620_Service_Manual.pdf

Page 34 is the fuel pump test

[hydromike]

I think he's all set.

there was believe it or not a hole in the carb right above the throttle shaft in the aluminum in a corner and that was allowing fuel drain down into the motor i used gas tank sealer(like jb weld)to seal the spot and havent had a problem since

[Bazooo guy]

Hope he didn't plug the bowl vent

[SixGunNick]

Ok guys I set up a gravity feed above the c arb after unhooking the fuel pump and it still surges I tried running richer and leaner and still .have the same results I cleaned the whole carb again and still the same deal my jet is either a 110 or a 118 does that sound right its really hard to read even with the magnifying glass so I'm guess maybe my throttle linkage got bent when removing the carb or the anti firing solenoid is acting up?IM also makin a new gasket right now for the manifold, i don't know I'm goin in circles now.I know u guys can only help me so long thanks everyone for your time

[Bazooo guy]

Solenoid valve test is on pg 32 of the manual
Main Jet should be 112
Pg 31 explains how to set the float level.

[Bazooo guy]

Nick I have seen many carbs that have been "professionally rebuilt" come to me and the float is not properly set. It seems most rebuilders will set the float to maximize the amount of fuel in the bowl. IMO its better to have the inlet needle close a bit sooner to avoid the possibility of it not seating. Vibration can play havoc on a float that is on the verge of closing and unless your engine needs more fuel than the pump can supply the bowl will stay full at wot. If its full and the needle is not seated it will build pressure in the bowl and the engine gets more fuel than it should.

[SixGunNick]

Nick I have seen many carbs that have been "professionally rebuilt" come to me and the float is not properly set. It seems most rebuilders will set the float to maximize the amount of fuel in the bowl. IMO its better to have the inlet needle close a bit sooner to avoid the possibility of it not seating. Vibration can play havoc on a float that is on the verge of closing and unless your engine needs more fuel than the pump can supply the bowl will stay full at wot. If its full and the needle is not seated it will build pressure in the bowl and the engine gets more fuel than it should.

Ok bazoo if my main is wrong can this be the problem cuz its definetly not a 112? I have noticed some tinkering that the previous owner had done around the carb area and can see that the fuel pump was unhooked and carb screws were mashed and a couple springs were in the wrong spots so what I'm trying to say is that this problem may have been goin on for a while before I had the machine I wouldn't have noticed much cuz I haven't driven it really at all since I bought it in september
I will chec on the float level setting that's really just somethin I'm scared to mess with.

[Bazooo guy]

I don't think the jet size will cause the problem you are having. i can tell you I have no experience with elevation tuning but the difference in jet size shouldn't cause it to surge as you describe. Adjusting the float level is very important IMO.
It's easy if you follow the manual and makes a big difference if not set properly. The thing that worries me is fuel in the oil.
My neighbors lawn tractor filled the crankcase with fuel and it wouldn't even turn over with the starter.because the inlet needle was stuck open. Prior to that I saw Him cutting his lawn with black smoke coming out the exhaust like a diesel engine. Have you looked at your plugs to see if both cylinders are rich? If only 1 plug is fouled you could have issues with valves or rings on the fouled cylinder. Fuel delivery is important but the engine needs to breath and have good compression. If both plugs are soaked with fuel it's probably the carb.

[SixGunNick]

Ok I am,not getting any fuel in my. Oil anymore the oil is perfect since I fixed the casting defect in side the carb and I dont think I had any engine damage at all cuz I caught it early on and changed the oil about 8 times and made sure all fuel was out of the engine until I found the hole in the carb casting. I will try to check the valve adjustment would I need new valve cover gaskets to perform this task or will they be ok.I would say.My jet is a 110 I picked the machine up about a couple hours away on the P.A. line and when I test drove it drove great so now if I drive it I can barely even turn or push snow at all as soon as I put a load on the motor it surges and I lose power and not just meaning the brakes causing it,it surges throughout throttle applied under load

[Bazooo guy]

I thought it was running good before the carb rebuild.
Change the jet to 112
If the gasket is not crushed or torn you can reuse it but they are cheap & easy to replace.
If the previous owner changed the jet from standard because of his elevation it won't run clean.
Did you pull the spark plugs?
When you pull the valve covers check that the pushrods are not bent or off their rocker.

[SixGunNick]

Ok I will change the jet, can I get one from any small engine shop do u think? And I will check the rods it seemed ok before but I seriously have rode it very little before this was happening and this is my first argo! My previous machine was a 72 max 2 stroke 6x6 two completly different animals

I haven't checked the plugs lately,because I haven't really takin it out for a good ride because of the issue I'm having will the plugs tell me the truth so to speak even tho I haven't had it out wide open at all? By the way what r the plug gaps supposed to be at 020? Do u know? That's what I have them at now.Thanks

[Bazooo guy]

If you give the small engine shop the serial # of your engine they should be able to supply the jet. Any #s on the carb.
Bring the old one with you if it's out or bring the carb. I guess it depends who is working the counter on weekends.

[SixGunNick]

ok thanks Should I also just eliminate my anti fire solenoid do u think

[JohnF]

It's not your float.
It is running lean (if it's a 110) or really rich (if it's a 118) or really really lean (a 108 - the high altitude jet).
I bet it's a 110.
Don't run in circles. Some of us have this machine and have been here before.

Be careful with all of the gaskets - they are more expensive than you might imagine. The jet will set you back a bit too. And I had to wait a couple weeks for the jets.

It's not the solenoid. If that fails or (more likely) gets stuck, then it won't run on the main circuit. It will be so lean that if you get it to run at all then it would have to be choked.
You can just take the solenoid off to see if it runs. I happen to know that someone posted the bolt size if you choose to delete it.