YT3000 won't start without starting fluid...

omerta14

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Hi.

Baffled by why my YT3000 21hp ohv(model 331977) won't start without a squirt of starting fluid. Over winter I replaced the head gasket as it was blowing smoke. I reset the valves clearances according to specifications and buttoned it up.

Went to start it this past week and it slowly cranks but will not start. (Battery fully charged). I eventually ended up spraying a bit of starting fluid into the carb and it fired right up. Stays running and runs smooth as silk. Shut it off and come back...same issue...will not start without a hit of spray.

No idea what it could be....It always started fine last year, just smoked like crazy.

Thanks for any guidance!

Mike
 

sgkent

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did it start after you worked on it, or is this the first try?
 

omerta14

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did it start after you worked on it, or is this the first try?
Thanks for the reply. This was the first attempt since I worked on it. I thought it maybe that I did not adjust the valve clearances correctly...went back and checked/re-did them....still same issue.
 

omerta14

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One other observation....when starting with no fluid the motor will turn slowly, stopping sometimes before resuming. When spray is applied, the motor turns very quickly and starts...

Thanks in advance for any help here.
 

StarTech

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While adjusting the valves did you check for the ACR bump of the intake valve rocker? If not present then the camshaft's ACR has failed. Quite common for the 793880 camshaft ARC to fail in the 31, 330000 series
 

slomo

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I bet a wooden nickel it's a fuel delivery issue. This time of year people are dragging out mowers with stale E-10 fuel from LAST YEAR.

Clean the cooling fins while you are at it.
 

omerta14

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While adjusting the valves did you check for the ACR bump of the intake valve rocker? If not present then the camshaft's ACR has failed. Quite common for the 793880 camshaft ARC to fail in the 31, 330000 series
Thanks, that does make sense. I did not notice that. I set TDC and then backed off 1/4" before setting clearances. The ACR bump you mention is when the valve opens a bit to relieve compression...at what point in my example here would I start to see that open.. thanks for your help!
 

SeniorCitizen

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Thanks, that does make sense. I did not notice that. I set TDC and then backed off 1/4" before setting clearances. The ACR bump you mention is when the valve opens a bit to relieve compression...at what point in my example here would I start to see that open.. thanks for your help!
With a maybe 0.002" feeler gauge between the rocker lever and valve stem and on compression stroke you can tell if there is an ACR bump and at what time in the stroke .
 
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