Bigger carb ?s problems

[Jake Dykstra]

So I swapped a 359 carb assembly onto my 353 and have an issue of running out of fuel.
Starts and tunes good for a minute or so. If I Rev it up or put some load on it, it seems to run out of fuel.
Does the lean bog thing and requires the choke to get it started again even after being warmed up.
Press test shows no bubbles.
Tank vent and filter are good
Thinking it's not pumping enough fuel. Maybe need lighter needle spring or ??
Any thoughts?
Thanks

 

[Canadian farm boy]

 

[Jake Dykstra]

Thank you. Very helpful

 

[Hulpio]

Hda174 or c3-el42 ???

 

[huskihl]

If it’s the Zama, you need to tap out the main nozzle and drill the hole all the way through the nozzle so it pulls fuel through 2 orifices rather than just one.

Also, make certain that the impulse system from the cylinder all the way back through the carburetor is perfect. If the boot and nipple aren’t lined up perfectly on the intake, you’ll get a weak impulse signal and the fuel pump won’t work well

 

[Jake Dykstra]

If it’s the Zama, you need to tap out the main nozzle and drill the hole all the way through the nozzle so it pulls fuel through 2 orifices rather than just one.

Also, make certain that the impulse system from the cylinder all the way back through the carburetor is perfect. If the boot and nipple aren’t lined up perfectly on the intake, you’ll get a weak impulse signal and the fuel pump won’t work well

It's the hda 199. Currently waiting on some parts. Swapped in a fuel pump diaphragm from a 372 carb for fun...well let's just say it's getting plenty of fuel now. Lol

 

[Jake Dykstra]

Thanks for all the help gents. Saw is running pretty good now.
K20 kit parts and it tunes great.

 

[Hulpio]

That is a nice one. Did bigger carb bring any negative effects? Like narrow powerband or something.

 

[Jake Dykstra]

That is a nice one. Did bigger carb bring any negative effects? Like narrow powerband or something.

Not that I can tell. Was just in need of a rebuild. I used everything from a 359.
Dropped right in other than needed to clearance the plastic where the choke/stop levers are.

 

[Hulpio]

Thanks for info. I've been trying to find el42 copy but so far all have been 15mm.
It is going to be hda174 then.

 

[Ketchup]

Not that I can tell. Was just in need of a rebuild. I used everything from a 359.
Dropped right in other than needed to clearance the plastic where the choke/stop levers are.

Are you still using the 372 diaphragm?

 

[Hulpio]

So a question: I will have chance to compare 4 different 353 cylinders next week:
1. oem 45mm, worn out
2. Winzor 45mm
3. Duke's 45mm
4. Farmertec 45mm
Should I make a separate thread with detailed pictures and perhaps some measurements?
Would it be useful or interesting?

 

[Jake Dykstra]

Are you still using the 372 diaphragm?

Not the one from the HD128 carb that was flooding it out. New one from the kit shown in Pic. Also made small adjustment to the lever that moves the needle open. It was flush with housing and I bent it down just a whisker (how over thick a whisker is lol). Maybe that helped maybe not. But it adjust like it should now.

 

[Jake Dykstra]

So a question: I will have chance to compare 4 different 353 cylinders next week:
1. oem 45mm, worn out
2. Winzor 45mm
3. Duke's 45mm
4. Farmertec 45mm
Should I make a separate thread with detailed pictures and perhaps some measurements?
Would it be useful or interesting?

Yeah more threads is always cool

 

[Ketchup]

So a question: I will have chance to compare 4 different 353 cylinders next week:
1. oem 45mm, worn out
2. Winzor 45mm
3. Duke's 45mm
4. Farmertec 45mm
Should I make a separate thread with detailed pictures and perhaps some measurements?
Would it be useful or interesting?

Info is always good but I would chuck all those in the trash and get a 346 kit.

 

[Hulpio]

44.3mm? Not 45mm?

 

[Jake Dykstra]

44.3mm? Not 45mm?

Yeah but a much better design

 

[Hulpio]

Would it be 544142907

 

[Ketchup]

 

[Hulpio]

Yeah, with decomp that 08.
I'll take that too if available.