Export thread

Metal vs Plastic Body Carburetors

#1

D

DPI

Is the metal body carbs of the early 70's better than the plastic body carbs of the late 70's, early 80's. And if so, is it worth retrofitting an older metal carb to a late 70's lawnboy if you can find one? Has anyone done that?


#2

Fireman 123

Fireman 123

I've read that the plastic carbs have tendency to warp from exposure to heat from the engine. I've never had that problem myself though. If the plastic carb you are referring to works fine, I would leave it. But in order to change to the metal bodied one, you also need to change reed plates. That is on the older D series engines. F series engines came with plastic carbs, and the metal Walbro carbs.


#3

R

Rumrunner

Not really adding anything here, but I recently liberated a 8253 (1976) that has the ALL plastic carb. When I say all plastic, that's what I mean except for the altitude adjustment needle and throttle plate. Even the float and needle are a one piece element. It's a D481 engine. When (if) I finally get it running or determine if it's going to run, I'll be interested in the prospect of a swap too. I had no idea Lawn-boy ever made a carb like this one. blah!


#4

impalass

impalass

Fireman 123 said:
I've read that the plastic carbs have tendency to warp from exposure to heat from the engine. I've never had that problem myself though. If the plastic carb you are referring to works fine, I would leave it. But in order to change to the metal bodied one, you also need to change reed plates. That is on the older D series engines. F series engines came with plastic carbs, and the metal Walbro carbs.
Click to expand...

On the later lawn boy they install a large plate between the carb and the engine to stop the heat transfer.


#5

D

DPI

I was curious since I have a plastic body carb on mine and the plastic float has a crack in it and needs to be replaced. The problem is, they are discontinued and finding another is very difficult.


#6

WhyZed

WhyZed

Rumrunner said:
Not really adding anything here, but I recently liberated a 8253 (1976) that has the ALL plastic carb. When I say all plastic, that's what I mean except for the altitude adjustment needle and throttle plate. Even the float and needle are a one piece element. It's a D481 engine. When (if) I finally get it running or determine if it's going to run, I'll be interested in the prospect of a swap too. I had no idea Lawn-boy ever made a carb like this one. blah!
Click to expand...

That sounds exactly like the carb on the D409 engine I have. One piece plastic float & needle (except for the rubber tip), and the only metal is the main jet, butterfly and the altitude bolt.. Crazy stuff..:confused2:
I tried to get the main jet out to clean it and was unsuccessful.


#7

impalass

impalass

WhyZed said:
That sounds exactly like the carb on the D409 engine I have. One piece plastic float & needle (except for the rubber tip), and the only metal is the main jet, butterfly and the altitude bolt.. Crazy stuff..:confused2:
I tried to get the main jet out to clean it and was unsuccessful.
Click to expand...

Lawn Boy 681843 carb assy on ebay for 130 dollars. I checked for the float p/n 681208 but no luck. This carb has a spring under the float.


#8

O

oldboys

DPI said:
Is the metal body carbs of the early 70's better than the plastic body carbs of the late 70's, early 80's. And if so, is it worth retrofitting an older metal carb to a late 70's lawnboy if you can find one? Has anyone done that?
Click to expand...

The carbs on early d600 engines will work on later 600 engines with modular carbs. The only thing is, the reed plates have to stay with their respective carbs.


#9

O

oldboys

oldboys said:
The carbs on early d600 engines will work on later 600 engines with modular carbs. The only thing is, the reed plates have to stay with their respective carbs.
Click to expand...

Also, yes they are better and much easier to get parts for.


#10

B

bayoudonnie

DPI said:
Is the metal body carbs of the early 70's better than the plastic body carbs of the late 70's, early 80's. And if so, is it worth retrofitting an older metal carb to a late 70's lawnboy if you can find one? Has anyone done that?
Click to expand...
Have a M320 craftsman mower that developed a very high idle. Went through the governor linkage and couldn’t adjust the spring tension do change anything. Took the plastic carburetor off and low and behold the governor flap was halfway into the engine. Briggs and Stratton has finally broke me. They are selling worthless expensive crap now and whoever came up with the never change oil idea must have been on drugs


#11

J

jdwalsh

DPI said:
I was curious since I have a plastic body carb on mine and the plastic float has a crack in it and needs to be replaced. The problem is, they are discontinued and finding another is very difficult.
Click to expand...
I realize this post is so old, the OP won't be helped, but I would try to weld the plastic float back together with an electric soldering gun or dedicated plastic welding kit like HF sells


Footer Links 1

Top