Trailfire Intake restricter

[Derfo]

I was looking at the parts catalog to find the part number for the boot between the airbox and the carburetor on an ‘80 Trailfire 440 and noted there is a restrictor (item 3 on the illustration) installed in the airbox inlet. I have owned 2 440’s and 2 340’s and don’t recall any of them having a restrictor installed. Now it could be that they were removed at some point because all of my sleds have led hard, neglected lives….. Anyhow all I can figure is that the restrictor could possibly be installed to keep it a bit rich at high power. Any thoughts? Should I be concerned about it not being installed?
Also, any workaround for the carb / airbox boot?

[snowmoer]

I checked the one on my 84 and there is no restrictor. It could have been a 1979 thing and JD determined that they did not need it. They just did not update the parts fiche.

There is someone on E Bay that had a new boot that looks like it would work. There are photos of one between the airbox and carb on a trailfire. Just search John Deere Trailfire and see if he has one up for sale. If not, keep checking back.

[10kTrailfire]

PM'd you.

[TwoDeereSleds]

While browsing the forum, I saw this and discovered my 1981 Trailfire 340 is missing Tube #5, but has the plastic Restrictor. I’m worried about it running too lean, so I’m hoping someone can tell me the material (aluminum/rubber?) and dimensions so I can try to find something that should work. Any info would be greatly appreciated!

Also, I can post photos of the restrictor, if interested?

Thanks!
TwoDeereSleds

1981 Trailfire 340
1975 John Deere 300

[AirborneX4Special]

Post pictures when you have a chance. I've never seen one.

[TwoDeereSleds]

It looks to me like it’s basically a reducer tapered down from approx. 2” down to 1.25” I.D.

Here’s a few photos:

TwoDeereSleds

1981 Trailfire 340
1975 John Deere 300

[jdsledhead]

Interesting. My '82 340 Trailfire does not have the restrictor, but I'm pretty sure my '84 440 does have it. I will double check tonight if I remember.

[AirborneX4Special]

It's like a tractor PTO shield. They get removed and never replaced.

[TwoDeereSleds]

I’m not sure I would use a PTO shield as a comparison as there are potentially fatal consequences of it’s removal. I’m sure millions were removed, but ours were not & I still have all of my limbs!

I could be way off-track here, but I presume the restrictor is designed to “meter” the air intake to sustain an ideal air to fuel combustion ratio. If removed, this could be compensated via the Carburetor Air Mixture setting, but I’m sure there is a very good reason it was included in the design by the original engineers.

As there was a different restrictor for the 440’s, it would make sense that the taper would not be as aggressive (perhaps down to 1.75”?) to supply a larger engine, so it may not be such a big deal if it is removed.

However, I suspect it would be much more noticeable for the 340’s if the air intake was 2” throughout. Again, this could be compensated via the Carburetor Air Mixture setting, but would not align with the original recommended setting of 1.5 turns out.

Thoughts?