SPITTING CARB - 914-6 all stock, Need assistance - please see latest post to this thread Options

[ctc911ctc]

1970 - 914-6 All stock

Got the car off the rack after a 1 year clean up documented here:

http://www.914world.com/bbs2/index.php?sho...3371&st=100

- tightened the lugs, check one more time for leaks.......

Car started first try, backed out of the driveway and went around the block

Drive strong.....very strong......

#2 cyl-carb is still 'spitting' definitely not backfiring. Chasing this through my trusty guide:

https://www.performanceoriented.com/special-procedures-1

See "notes" section

Seems that when I performed the Lean Best Idle procedure #2 failed during the procedure......the diagnosis within the document states that either the path in that carb #2 is blocked or the jet is the wrong size - my bet is a clog......though the carbs were very clean when I got the car.

There is a little noise from the right side, that in a 914-2L 4Cyl would be considered quiet, my hope is that it is not valve noise and may be exhaust leaking......did I tighten the heater manifold small nuts????? dry.gif

Carb advice sought from those that have chased a SPITTING Carb

[ctc911ctc]

Less than 1 hour of run time between now and this measurement earlier in the year.

1 - 162
2 - 167
3 - 166
4 - 165
5 - 166
6 - 161

I have the leak down numbers somewhere - but I recall them to be consistent as well,

The valves were all set when the engine was out and on the stand - there is a mention of this within the rebuild thread

Thank you!

ON to the carbs!

[Superhawk996]

Less than 1 hour of run time between now and this measurement earlier in the year.

1 - 162
2 - 167
3 - 166
4 - 165
5 - 166
6 - 161

I have the leak down numbers somewhere - but I recall them to be consistent as well,

The valves were all set when the engine was out and on the stand - there is a mention of this within the rebuild thread

Thank you!

ON to the carbs!

Just to clarify- with respect to spitting the location of leakage matters not the absolute numbers

Example: let’s say all cylinders are excellent with say 5% leak down.

But let’s say cylinders 1, 3-6 are primarily leaking 5% past the rings - great all is good and pretty normal due to ring gapping, cylinder sealing, etc.

But let’s say cylinder #2 is leaking 5% all past the intake valve seems great but not really - you will have spitting on #2 and more trouble tuning that cylinder.

Clearly I’m making up a pretty extreme example here to make a point. Not trying to imply this is what is going on in your case.

The point being - where the leakage is at matters in conjunction with the absolute leakage percentage. You’ve got to understand what is being measured, know where the leakage is at; that is the power of a leak down test Vs. compression test. There is more to it than looking at absolute numbers or leak down percentages.

Focus on the carbs but if you can’t get there - recheck assumptions.