30 hp fuel problems? help!

[bullcity101]

good morning!

I will start with, I am very furstrated that I can't figure this issue out. ugh! I will start with the issue and then tell what I have done already to try and solve the issue.

I have a 1985 envirude 30hp. The issue is, it will run for a few seconds after I pump the manual primer (not the primer bulb, the primer that is ran via tubing off the float bowl). and after that fuel is consumed it dies. After that I have to pump the primer bulb till firm and the pump the primer, and then have the same results.

Now here is what I have done. I have rebuilt the carburater, and cleaned the entire thing with carb cleaner and compressed air. I did a thorough job, taking out every plug and blowing out every oriface and every jet. After doing this and having the same results, my thought came automatically to the fuel pump. I took off the fuel line to the carb and turned the engine over and the fuel shot out two or three inches, so this tells me the fuel pump is working correct? Is two or three inches enough pressure? I took off the cover to the pump and check for blockages in the screen and it is very clean. I have also, put in a water sperater filter, this is after the fact so i don't think that is the issue. And i don't think bad fuel is the issue as it purs like a kitten for 10+ seconds with the primed fuel. Compression readings are great, ingnition is working properly. Any ideas?

Also another question is, is there a bearing for the low speed needle deep in there on this model carb? Also what is the stock setting, I took it to firm and took it 1 and a half turns out. Is that enough? Could that be the issue? I also thought that the float needle is getting stuck, nope I can hear the float move when i shake the carb, I also just had it open and put brand new stuff in.

If you would like me to post a video, just let me know.

Please give me all the suggestions you all have.
Thank you in advance, you all are so helpful!!!!
John

 

[kbait]

Re: 30 hp fuel problems? help!

Sounds like your fuel pump is fine.

I'd have a squirt-bottle of premix fuel handy and try again w/carb silencer off (if applicable) so you can have access to the carb throat. Start w/primer and lightly spray premix into the carb throat. If you can keep it running by adding premix, you obviously have a fuel delivery issue.. and it pretty much has to be the carb, as you tested the pump. Make sure your carb's link/sync is correct (throttle valve just starts to move when cam roller hits mark on cam). If your throttle plate is completely closed when you're trying to start, this could be your issue. The primer shoots a bit of fuel behind the throttle plate, and it's available to enter the cylinders, and that'd explain why it runs w/prime, and not when that fuel is consumed. If the link/sync is correct, and the throttle plate is indeed open a bit upon starting, you likely have a carb issue. The float 'rattling' doesn't tell you the needle is opening.. You can check that prior to installing the carb by blowing through the carb fuel inlet(air should pass) w/carb upright. Then invert carb and blow through inlet(air should not flow through).

Good luck!

 

[jasper60103]

Re: 30 hp fuel problems? help!

good morning!

...

Also another question is, is there a bearing for the low speed needle deep in there on this model carb? Also what is the stock setting, I took it to firm and took it 1 and a half turns out. Is that enough? Could that be the issue? I also thought that the float needle is getting stuck, nope I can hear the float move when i shake the carb, I also just had it open and put brand new stuff in.

If you would like me to post a video, just let me know.

Please give me all the suggestions you all have.
Thank you in advance, you all are so helpful!!!!
John

Good advice above.
Regarding the bearing.
I have the same motor and carb, except it's '88.
I've been told the carb low speed needle has a bearing. Also, the carb kit includes one, but I didn't change it.
I think its worth checking especially in your case.

 

[bullcity101]

Re: 30 hp fuel problems? help!

Does anyone know the stock setting for the low speed needle? I didn't change the bearing that comes with the kit, as I have heard it's a *$"&$( to get out.

Kbait - I am pretty sure the needle on the float is letting fuel in as the primer works off the float bowl, but still something to check. I will try to run it at different throttle settings to get different reactions, I have been trying at what it has liked in the past, throttle vavle slightly open. Also It does run with just premixed being squirted in.