Won’t start unless primed

[ThatOneGuy1968]

I have a Briggs 18.5 Intek..
Model 33R7770003G1..
I replaced to decompression mech with a new cam.. Then replaced the head gasket.. my intake set at .004.. my exhaust at .005..
The flywheel key is good.. it has good spark at the plug..
Everything was going fine until you try to start it and it will not start unless you prime it with carb cleaner but will not stay running..
I cleaned the carb completely to no avail.. I got a used carb from my old mower which appears to be the same carb called a Nikki..
Still no start.. cleane that carb too .. still no start..
Am I missing something..

 

[SeniorCitizen]

Is it getting supplied with gas to the carburetor ?

 

[Rivets]

Are you sure the fuel solenoid is opening? Grab the solenoid with one hand and turn the key to the run position, not start. You should feel it kick in and/or hear it click.

 

[ThatOneGuy1968]

Are you sure the fuel solenoid is opening? Grab the solenoid with one hand and turn the key to the run position, not start. You should feel it kick in and/or hear it click.

Well no not exactly.. I did put a different one on the carb.. I’ll have to get back to u on this one..

 

[Rivets]

I did notice that two different solenoids were used on that engine, depending on if you have a Nikki or Ruixing carb. That can not be interchanged. Look here. https://www.partstree.com/models/33...uretor-fuel-supply-kit-carburetor-overhaul-3/

 

[ThatOneGuy1968]

I did notice that two different solenoids were used on that engine, depending on if you have a Nikki or Ruixing carb. That can not be interchanged. Look here. https://www.partstree.com/models/33...uretor-fuel-supply-kit-carburetor-overhaul-3/

Both carbs are Nikki..
I ordered a new one this morning..
The reason I have an old one is because about three years ago before I understood and worked on lawn mower engines myself we to it to jacks power equipt after I had tried everything that was suggested by a mower tech and they replaced the carb with a new one and that lawn tractor ran just fine after that..
I couldn’t find but one 3 letter number and I think one additional number on the carb, so I looked it up on the Briggs online store and got a part number..

 

[ThatOneGuy1968]

Is it getting supplied with gas to the carburetor ?

Yes.. I took the gas tank off and flushed it because there was all kinds of crud it it.. I just don’t get it so I’ve ordered a new carb..
not sure what difference it’s gonna make being I thoroughly cleaned the original carb..
Guess we’ll see..

 

[Craftsman Garage]

Both carbs are Nikki..
I ordered a new one this morning..
The reason I have an old one is because about three years ago before I understood and worked on lawn mower engines myself we to it to jacks power equipt after I had tried everything that was suggested by a mower tech and they replaced the carb with a new one and that lawn tractor ran just fine after that..
I couldn’t find but one 3 letter number and I think one additional number on the carb, so I looked it up on the Briggs online store and got a part number..

They are a bit finnicky, make sure you are choking it when starting, because it will make the mixture richer and almost simulate starter fluid. Sometimes it's just time for a new carb, and make sure you are starting it a lot. That seems to keep the carb clean. Good luck, that is a great machine you got there!

 

[ThatOneGuy1968]

Well no not exactly.. I did put a different one on the carb.. I’ll have to get back to u on this one..

It doesn’t click and neither does the one I had and put on it..
New carb is supposed to be here today..

 

[bertsmobile1]

here are 2 types of solenoids.
One has 2 wires and the black wire will go to a small bolt on the engine some where
These do break off or fall off
The other kind have 1 wire and ground through the carburettor body
If the carb is mounted to a plastic manifold there will be no ground so they have a small jumper to ground the carb body
The wire usually gets lost when the carb is removed .