Carburetor main jet drilling

[ft. churchill]

I've got a saw of my buddies (echo cs-8000) that after a base gasket delete, clean up of the ports, .030" off of the top of the exhaust port and a muffler mod, the carb no longer tunes in nice. I'm 4 turns out on the high side jet to get it to four stroke, and even then it not a good strong four stroke like it should be.
Here's my questions. Where do you drill to increase the flow through the high side jet to get it back down into the one to two turn off of the seat range? The carb is the walbro with/ the check valve in the main nozzle .
Or am I up against some limiter in the ignition coil?

Normally when I go too far on the muffler opening, I get into the saw will not idle well and low speed tuning jet issues, and that is not the case with this saw. It like it is starving for more fuel on the high speed, and the high speed jet is so far out that the main jet orifice is the restriction to more fuel flow.

 

[srcarr52]

You could have your metering lever set too low and it can't open up enough to let the fuel needed in.

 

[ft. churchill]

I will have to check for that Shawn, thank you. I the carb was fine before mods, but after mod I picked up quite a bit more RPM's and compression.

 

[Poleman]

I did one of those a couple years back and had to put a small air hole in the throttle plate to get it to Idle, other than that it was good and had a lot of adjustment.....I think tour on the limiter!!! I'm thinking their 12,8K. You should see lot better performance from what you've done....but limited by the coil....

 

[Redfin]

Have you tried to cut with it yet?

Edit: Just thinking if it is the limiter, in the wood you should be really rich with the H out that much.

 

[Poleman]

Redfin, your right....needs to be tuned in wood...

 

[ft. churchill]

I tuned in the wood, and it's not surging like the diaphragm chamber is running low. It just does not have a crisp definition between rich and lean and I'm an awful long way open on the high speed jet.

 

[Poleman]

Everything is out the window with any stock settings with a modded saw. My modded Dolmars will not run to lean and need a lot of fuel to run right. They would be waaaay rich if they were in stock form the way they are set now. They are tuned to about 14,4K no load ant turn a lot of r's in wood. They are tuned to best run ability and not anything close to stock nor would they even run that way.

It sounds like your running out of fuel and may need to raise you needle arm slightly to get more fuel. Where to drill would require a carb that would be compatible with jets to do....not sure what carb is on the 8000.

 

[David Young]

Any chance the impulse passage has been blocked or impeded?

Ive ported quite a few saws with more mods than that and they don't vary from stock settings that much.
maybe 1.5 turns out. more than that I look for a problem.