1450 difficult to start - Page 3

Terry C · #21 03-26-2015, 07:59 PM

Quote:

Originally Posted by sundown

Looked at the points today, had some buildup on them and there was barely any gap even after cleaning. I set it to recommended clearance. But I think I have bigger issues. After removing carb to get ready to rebuild I could see carbon buildup on the underside of the intake valve. I removed the head and its ugly. Lots of carbon on the valves and there is a thick buildup that hangs out past the cylinder wall that appears to have worn the top of the piston in that spot. Time to make some decisions about the future of this rig...

I would like to see a pic of that

sundown · #22 03-26-2015, 10:42 PM

Across from the exhaust valve there is a heavy carbon deposit around the top of the cylinder. You can see more of a gap between the piston and wall when the piston is down right in that spot. The other picture shows the intake valve

Terry C · #23 03-26-2015, 11:03 PM

I think you might need more than a carb rebuild. Jon will access those pics much better than I can but I think I can see the top ring in the one pic. That's quite a lot of piston to cylinder clearance

sundown · #24 03-26-2015, 11:12 PM

The top ring can be seen when looking down at the piston. The rock hard buildup wore the edge of the piston right off. I was trying to decide what was going to get a crazy repower, this one or my 1811. I think it will be this one...

cubby102 · #25 03-26-2015, 11:14 PM

I think it was more the piston was slowly eaten away by the head and the carbon built up from the oil getting past the rings. But eather way at bare minimum a hone new piston and rings... they are cheap enough to rebuild I think id stick with that engine

J-Mech · #26 03-26-2015, 11:15 PM

Definately not a lean condition..... just as I suspected. More than likely it was: weak spark, incorrect timing, and low compression.

More pics would help.
Need to see:
~One of the entire deck area prior to cleaning.
~Better ones, closer to the piston, and with it at the top.
~Pic of the exhaust valve with it open just like the one of the intake. Before cleaning.
~Pic of the cylinder head before and after cleaning.
~Clean it all up, and post a pic of the piston at TDC showing the whole deck.

Well go from there. Engine may be toast. One step at a time, and don't do anything besides take pics and clean it.

J-Mech · #27 03-26-2015, 11:17 PM

Quote:

Originally Posted by cubby102

I think it was more the piston was slowly eaten away by the head and the carbon built up from the oil getting past the rings.

I don't see how you can tell that from the pics he posted. Piston looks fine from my seat..... But it's awful far away in that pic.

Terry C · #28 03-26-2015, 11:20 PM

How did that build up get on the bottom of the intake? Incorrect timing?

J-Mech · #29 03-26-2015, 11:28 PM

Quote:

Originally Posted by Terry C

How did that build up get on the bottom of the intake? Incorrect timing?

Most likely:
~Low cylinder temps along with poor fuel quality (dirty) and dirty air (no filter/bad filter dirt entering somewhere)
~Dirt

Other possible causes:
~Worn valve and guide along with plugged air filter causing it to suck oil past the valve stem. Possible plugged drain in the lifter galley.
~Dirt

That much crap on the bottom of the intake usually means dirt. You see it all the time on engines with EGR and crankcase vents that feed into the intake...... or engines that have intake ducting leaks (dirty air). Did I say dirt?

sundown · #30 03-26-2015, 11:33 PM

This is the only other pic I have, I can get more tomorrow. The dark line between the piston and cylinder wall on the exhaust side (right side of pic) is not a shadow, its a gap with the worst part being right in line with the exhaust valve. The other half of the piston is tight to the wall. When the piston is at TDC the gap is gone, it is tight to the thick area of carbon at the top of the cylinder. It really looks like the edge of the piston is eaten away.