Carb replacement for 218

[wings515]

I have had my PT81 for about 25 years and after the last engine re-build this Spring all seemed to be good.  I looked at the tail pipe and noticed it was black and I think it should be gray.  Another indication it is running rich happened this weekend.  I returned from a show and had to shut off the engine to enter my home.  When I went to restart it it seemed flooded.  I did finally get it started but now I am wondering if I have the correct carb for this engine.  It is a D6G1 that was rebuilt two years ago.  I have also replaced the vacuum advance and set the timing at TDC.

 

I read on this forum about replacing the Carter with a W1 carb from a Chevy.  Is that a good alternative?  There are some W1's on ebay for under $100 but they would have to be rebuilt.

 

Regards,

wings515

[jeffsunzeri]

No, the Chevy W1 is not a good alternative.

Some better diagnostics are in order other than a hard-starting incident and sooty tailpipe.

If the carb was rebuilt two years ago, how did it perform then? There are about 70 quadzillion things that might account for hard starting, and black soot in the tailpipe is not a concern at all for a carbureted engine. It should not be gray.

 

[Adam H P15 D30]

The fuel now days tends to boil over easily so some here slightly lower the float level to combat this.  Fuel today burns differently then when these engines and carbs were spec'd out, I would put a few 4-5 degrees of advance in and see if starting / driveability improves.  I think the happy spot on my 230 is about 6 BTDC.

 

Adam

[wings515]

To answer the first question, even before the new rebuild the tailpipe was always black.  When I re-assembled the engine this Spring I could only get the distributor to time at TDC with the wires in the cap the way there were originally.  The adjustments on the base of the distributor are at the extreme end of the travel. Since the show time is nearing the end of the season, next year I think I'll rotate the wires in the cap and reset the timing.  I'll take the suggestion to advance 4-5 degrees to see what happens.  

I'll also look into lowering the float level, probably 1/32".

 

The suggestion not to use a W1 Zenith carb will save about $450.  I have seen this carb on ebay for under $50 but it does not have the correct throttle mechanism.  I have multiple other Carter carbs to mix and match but I will try the timing first.

 

Thanks for the suggestions.

Dan

[Los_Control]

nothing wrong with experimenting with the wires.

I learned the hard way to put it on TDC and then check.  Mine actually would not start when rotated one position either way.

Is actually pretty easy on these engines, Pull the pipe plug over #6 cylinder, rotate engine by hand, when compression comes out ... then use a wire to get piston at TDC.

Now you have #6 on TDC, your rotor should be pointing at #6 wire. Just start wiring it from 6 instead of 1.

Just simple on these engines, just pull the 1/8" pipe plug and use something to tell where the piston travel is. Do not even need to pull a spark plug.

 

Just my experience, maybe your engine is in better condition and will run if the wires are rotated one position off, mine wont.

[Fernando Mendes]

I always use this tire measure thread instrument inside the #6 cylinder hole.Under this #6 spark plug hole is the #6 intake valve.When the instrument begins to rise the #6 intake valve begins to open or the end of the exhaust stroke(TDC).In this same moment #1 cylinder is in FIRE stroke(TDC).

[Merle Coggins]

That's a great idea. I've got a couple of those tread depth gauges laying around.

When #6 intake starts to open, and lifts the gauge, line up your TDC mark on the pulley and your distributor rotor should be pointing at #1 plug wire.

[Fernando Mendes]

42 minutes ago, Merle Coggins said:

That's a great idea. I've got a cou, ple of those tread depth gauges laying around.

When #6 intake starts to openand lifts the gauge, line up your TDC mark on the pulley and your distributor rotor should be pointing at #1 plug wire.

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