372XP/OE - Fix RWJ4 or Swap for 390XP Carb?

[XP_Slinger]

Howdy gents,

Looking for some experienced opinions on the subject line. I currently have an RWJ4 on my 372 and was thinking about trying out a 390xp carb because the tune doesn’t seem stable with the RWJ. Saw passed pressure/vacuum test with flying colors. My question regarding this...is the juice worth the squeeze? Would be interested to hear what any of y’all think that have run one or both. Thanks.

 

[huskyboy]

390/395xp carb if your doing a straight bolt on. Straight bolting on the rwj... it runs finicky. If you drill the jet in the rwj it runs very well though and tunes like the stock HD12. I ran a 2171 that had a rwj that was modified and it behaved very well.

 

[XP_Slinger]

390/395xp carb if your doing a straight bolt on. Straight bolting on the rwj... it runs finicky. If you drill the jet in the rwj it runs very well though and tunes like the stock HD12.

That’s where I’m at Mason, tune wanders with the RWJ and the jets are out what I would consider an excessive amount. Something isn’t right. Guess I should’ve put that in the original post.

Never heard that drilling the main fixes it, heading to the barn now to mess with it.

 

[huskyboy]

I really like the tillotson 296/298/300 carb. If you can find one they are a well behaved carburetor. That said either the walbro or tillotson works well with the boot turned, you just have to ditch the carb screw adjustment boot. I can’t remember if I modded the throttle cable or not. I think I took some material off the cable holder on the carb so it would return to idle. All this said, I really think the standard equipment HD12 is just fine on a worksaw if you are not racing at a gtg.

 

[XP_Slinger]

I really like the tillotson 296/298/300 carb. If you can find one they are a well behaved carburetor. That said either the walbro or tillotson works well with the boot turned, you just have to ditch the carb screw adjustment boot. I can’t remember if I modded the throttle cable or not. I think I took some material off the cable holder on the carb so it would return to idle. All this said, I really think the standard equipment HD12 is just fine on a worksaw if you are not racing at a gtg.

I agree, Joes XPW has the standard HD12 and his saw doesn’t seem to lack anything compared to mine with the RWJ4. Mine was an XT conversion, that’s why I have the RWJ.

And this is definitely a work saw

 

[Steve]

I agree, Joes XPW has the standard HD12 and his saw doesn’t seem to lack anything compared to mine with the RWJ4. Mine was an XT conversion, that’s why I have the RWJ.

And this is definitely a work saw

I did the xt to xpw conversion on mine. Im running a Zama C3 EL2. Im not a walbro fan. Mine is also ported and runs very well and holds a tune very well.

 

[XP_Slinger]

I did the xt to xpw conversion on mine. Im running a Zama C3 EL2. Im not a walbro fan. Mine is also ported and runs very well and holds a tune very well.

Thanks for the input Steve. Much appreciated.

 

[Steve]

Thanks for the input Steve. Much appreciated.

They where used on the early 372xp before the walbro hd.

 

[huskyboy]

They where used on the early 372xp before the walbro hd.

On early 365/365 special they used the zama I believe, then later changed to HD12. The 371 used a HD6 walbro (basically a earlier non - epa HD12 with a tiny bit smaller venturi and no limiter caps).

 

[dustinwilt68]

I dispise the rwj4, hd12,hd6, 390 walbro carbs and the Tilly's or the Zama from a 7910, all work well for me

 

[Steve]

I dispise the rwj4, hd12,hd6, 390 walbro carbs and the Tilly's or the Zama from a 7910, all work well for me

This!!!

 

[NPKenny]

I dispise the rwj4, hd12,hd6, 390 walbro carbs and the Tilly's or the Zama from a 7910, all work well for me

I’m no stickler on grammar, but I can’t follow your punctuation. Which do you despise and which work well?

 

[Onan18]

Tilly 296 or 298, they can be had new from the internets for considerably less than Husqvarna wants for a HD12.

 

[Steve]

I’m no stickler on grammar, but I can’t follow your punctuation. Which do you despise and which work well?

Walbro carbs just suck. Period.

 

[beaglebriar]

Good timing on this. I'm on the middle of a XPW build, waiting on a intake boot actually. I plan to use a 296 but the RWJ hasn't been ruled out. I'd like to know what size folks are drilling the main jet to??

 

[huskihl]

In my experience, if the tune wanders, I think there’s something else wrong. The RWJ does seem finicky and weird, but it’s more a matter of mid range RPM that it acts weird to me. Likes to run rich from 1/8 - 1/2 throttle. Be careful drilling the jet. I’ve done it and at .1 MM larger, the saw will barely clean up in the cut. Wants to four stroke all the time. They still continue to deliver more fuel even at 3.5 turns out on the H jet. At 4 turns the jet starts to get sloppy. Most of the 372’s I’ve done that have the RWJ are at 2 - 2.5 turns out. I’ve also used the 390 and 395 carbs on them. And honestly, they do tune easier and act more normal. I can’t tell the difference between them and the RWJ as far as performance

 

[huskihl]

This one has the RWJ

This one has a 296 or 298

https://youtu.be/qMaDUjbI5h4

 

[beaglebriar]

In my experience, if the tune wanders, I think there’s something else wrong. The RWJ does seem finicky and weird, but it’s more a matter of mid range RPM that it acts weird to me. Likes to run rich from 1/8 - 1/2 throttle. Be careful drilling the jet. I’ve done it and at .1 MM larger, the saw will barely clean up in the cut. Wants to four stroke all the time. They still continue to deliver more fuel even at 3.5 turns out on the H jet. At 4 turns the jet starts to get sloppy. Most of the 372’s I’ve done that have the RWJ are at 2 - 2.5 turns out. I’ve also used the 390 and 395 carbs on them. And honestly, they do tune easier and act more normal. I can’t tell the difference between them and the RWJ as far as performance

My 371 is running the RWJ without issue. Takes patience to tune for sure though and it seems more sensitive to temp change than other saws.

 

[Lightning Performance]

Can the 395 carb be stuffed into the 64xx?

 

[huskihl]

Can the 395 carb be stuffed into the 64xx?

Not dependably without making some sort of mount to hold the carburetor down and provisions for a V stack and a different type of air filter. The stock Dolmar air filter needs to be carved up and it still pinches the impulse and hits the high idle mechanism