5hp still not running

[backdraft341]

ok i know yall are getting tired of my post but my 5hp model#130202 still will not start. it will fire a few times then backfire some of the times. it has good spark. i has a pulsa jet #2 carb. i have replaced both pick up tubes jet and needle valve. cleaned the carb inside and out many times. new diaphram. doulble checked the timing. cam and crank dots are lined up. trying to start without air breather make a diffrence? compression is 90. im getting frustrated.

 

[C9H13NO3]

Did you check the fuel line?

 

[Big Boi]

Are u getting a good spark? And adjust the fuel ratio and see if that helps.

 

[backdraft341]

it has pick pick up tubes and there new. also it has good spark and i have messed with the fuel ratio from one end to the other. dont know where to turn next.

 

[Ibanez616]

Just an idea, I am guessing that somewhere in the carb there is some debris that cannot be removed for some reason, So take of EVERYTHING possible from the carb and soak it in some gas or something like it for a few days, then try to blow through it with compressed air.

 

[badtec]

Make sure that the long tube isn't bottomed out in the tank. Good luck.

 

[Bill Ellerby]

Personally if it backfires that is a timing issue. It wouldn't hurt to ensure that you haven't partially sheared the flywheel key thereby throwing off the timing? This has happened to me twice.

 

[The Restore Kid]

Personally if it backfires that is a timing issue. It wouldn't hurt to ensure that you haven't partially sheared the flywheel key thereby throwing off the timing? This has happened to me twice.

That or the valve lash... Sounds like it might be a worn down motor and needing the vales done... Can't pull fuel for crap, then it does get some in there and explodes it back out the intake valve.. :doah:

 

[cxbra]

I dont think he means its backfiring, more like a lean firing situation. I had the same issue for a while w/ my Briggs when the long pickup tube was clogged. Cleaned it and never had the issue. He said his are clean tho.

Backdraft, I know what sound you're talking about, like it gets gas for a second and ignites and then sputters (higher pitched kinda popping, like a 2 stroke huh?) Mine has done that on occasion, i've always traced it down to it running lean from the carb malfunctioning. Here's the major test; pour gas down the opening of the carb, pull a few times to prime it. Pull a few good pulls and if it starts, that means you're carb is malfunctioning and fuel if the direct pour of fuel into the carb works as a bypass.

 

[backdraft341]

is doing a valve job consist of getting new valves lifters and springs? when i took the side cover the dots on the cam and the small gear on the cam were still lined up. can i still have a partally sheared pin? are you talking about the pin on the crank for the flywheel?

 

[Bill Ellerby]

Yes the key for the flywheel to crankshaft.

 

[funky ole]

at 90 psi,the engine should fire.if the cam timing was off a tooth,compression would not be that high.each tooth is about 7.5 degrees of cam timing.
have you tried what someone else had said?supplimenting fuel or starting fluid to see if it would run at all? or does it backfire and stall when this is done? if it backfired and died,then you have an ignition timing issue,sheered key,fouled plug,ect.
if your engine ran then died when the supplimental fuel was gone,you have a carb issue.

 

[jeep2003]

got good spark? See if it starts with starting fluid? carb should be set at about 1 1/2 turns out.

 

[Cyanide]

turn up the idle screw:shrug:

 

[Tom S.]

Yes the key for the flywheel to crankshaft.

Like this:

 

[jeep2003]

Yup thatll show good spark but backfire and kick back or just not run at all

 

[cxbra]

Make sure the engine ground wire (the killswitch wire) isnt touching the engine.:shrug: