Honda HRB 476c -Will not start, only runs for 2/3 Seconds??

[bilabonic]

Yes everything seems free tbh, i can't figure out how the throttle valve assembly actually works tbh with the spring etc and the screw on the rev limiter that it will NEVER hit?
I made a note of the direction of the EM, it's in the correct way, i noticed the large hole going through it at the bottom.
Thanks

 

[lostinthelight]

If you input your engine model in the search box you can download a cut down version of the shop manual which may help.
https://www.honda-engines-eu.com/shop-manuals

 

[Burnerman]

Hell this is getting worse
Did you manage to get the gaskets and plastic heat insulating block back in the correct order?
The throttle needs to be held in the open position when the engine is off.....the throttle stop screw and spring only get contacted when the engine is ticking over.
John

 

[bilabonic]

Yes all, gaskets in order, insulating block/plate all fine. The throttle stop screw is back as it as it should be (barely visible/1 or 2mm protruding).
In no way can i see how the throttle would fully go around and hit the stop screw though, it's not moving at all, i would have to pull on it manually to fully rotate it looking at it....

 

[Burnerman]

The throttle should be free to move......is it jammed solid?
John

 

[bilabonic]

It's all free.

 

[Burnerman]

I'm stuck now!
All I can say is that if it was mine I'd consider a replacement carb from GHS or whoever but I'd also check that the flywheel key is intact.
I'd also take the rocker cover off to check out the valve operation. Neither of these faults are typically Honda but Briggs engines do suffer.
How does the engine run now?
John

 

[bilabonic]

Where is the flywheel key?

Everything operates as it should though, i just have to keep the choke on/handle pushed fully forward, then i can engage the blade and the roller drive.

I'm at a loss as well tbh, how many turns should the idle screw be out? Think it's called the idle screw, it just pokes a small brass pin into the carb.

I think i will take it to a friend who has an air gun to clean it......

Cheers

 

[lostinthelight]

If this issue appeared following a period of storage after working ok the previous season, personally I wouldn't have thought it was flywheel shift related

 

[bilabonic]

Tbh, the last couple of seasons it's been hunting but nothing like this, why has it altered from only running from 3 seconds to running all the time just by cleaning the carb? (Albeit with full choke on).
What is the reasoning for it to be the flywheel?? The clutch/flywheel etc must be ok as i can engage the blade and self propel if need be.....
Am i missing something here.....
Thanks

 

[Burnerman]

The idle mixture screw should be 1 1/4 turns out from fully in. As you adjust it the engine revs will change slightly, but not immediately.
Symptoms of a flywheel key failure- the engine won't run but it will fire once or twice.
I don't think this is your problem but you have done everything else!
If the engine runs on full choke there has to be a restriction on either the float valve or the main jet.
John

 

[bilabonic]

The stupid thing is i am not able to adjust the screw whilst it is running, the pull start cover needs to be removed to gain access. (unless i can bodge a flexible driver of sorts onto it).
Plus i have tried from 1/2 turn out all the way to 4 turns out in 1/2 turn increments.
Blowing a gale today and next few days so can't fiddle with it.

 

[Burnerman]

The idle speed screw is indeed hellish to reach.....I have a long philips driver that I can just about get in.
When you have time, post up a few carb pics if you will, we'll identify all adjustment screws just to make sure we're referring to the same thing.
John

 

[bilabonic]

Stropped the carb down again today and replaced ALL the gaskets.
I did find one tiny hole blocked in the emulsion tube (where it has 4 squirting out just one was blocked).
Cleaned EVERYTHING again, put back and runs but again only when i physically push down on the choke handle.
I can even engage the blade/self drive like this.

I'm at a loss here now tbh as to what happening, it's spotless, bowl is filling fine, float fine, carb spotless, needle screw is out 1 1/2 turns although where this is makes NO difference as it needs full carb.

All linkages/cables are working fine?

Where do i go next guys, will any carb part numbers or pics help?

I'm determined to get this running and get some stripes back in my VERY neglected 'lawn/jungle'.

Thanks

 

[Burnerman]

Three points, if I may!
The part of the carb that the emulsion tube and main jet screws into....did you notice a drilling in the side that allows the fuel into the main jet?
Next, the idle mixture screw on these has a lead cap on it that only allows you to turn it a few degrees before it comes up against a stop. Did you manage to remove this?
Next, the gaskets must be the correct way round so as not to block some of the passages. Are you happy enough with these?
(Not sounding to be patronising, mate!)
John