8 replies to this topic

[Craig Tett]

Have just taken the head of my 1275, replaced a valve top cap and changed from 1.5:1 roller tip rockers back to standard and now it won't start.  It cranks over ok for a few turns then slows down almost to a stop before then putting out a big puff from the carb (HIF44) breather.  I've had the head on and off loads of time in the past and can't think of anything I've done differently this time.  I've double checked the tappets and none of the timing or electrics have been touched.  It's almost like it's not exhausting the gas down the normal exhaust route so that pressure builds up so much that it forces it way back out the carb breather.  Any ideas??  I'm stumped. 

[Northernpower]

Have you checked the plug leads are back in the correct order? Plug gaps ok?

[Craig Tett]

Yep, I'm pretty certain (might just go check again though!), always take a photo and they match up.  Plug gaps haven't been touched so should be fine.

[Northernpower]

Yep, I'm pretty certain (might just go check again though!), always take a photo and they match up.  Plug gaps haven't been touched so should be fine.

If you've had the plugs out there's a chance you may have dropped one on the tip and or somehow closed the electrode up. If you left them in the head you may have caught them with the spring compressor. For what time it takes it may be worth checking.

[Craig Tett]

True, I'll whip them out and get the feeler gauge on them.  Fingers crossed.  Thanks.

[Craig Tett]

Plug gaps all at 0.8mm, leads on correct order 1-3-4-2.  Same scenario. I feel like it must be something obvious but I've no idea what!

[panky]

You sure the fuel line is on the inlet and not the float chamber vent.

Edited by panky, 17 July 2017 - 08:58 PM.

[Craig Tett]

Fuel line goes in at the lowest inlet. Breather goes in at the upper and most forward one and the overflow is in between.

[Craig Tett]

And it does have fuel, just checked that after having a sudden panic