how do I Change the main jet on a 346xp

[COWBOYJAKE]

I bought a non kalifornia main jet for my 346xp, I figured I could get a bit more fuel and hp out of it with this jet. And while I have things in pieces I am going to file off the adjuster stops. I can not seem to figure out how to get the main jet out. how do I get it out??

Thanks!

Jake

 

[striperswaper]

why change the jet?
ur in TX so?

 

[mtngun]

You don't need to change the main jet unless you are out of adjustment on the "H" screw.

 

[COWBOYJAKE]

I figured the non kalifornia jet would be a larger jet so when I do some mods I could pickup some more power. The CA saw comes with a different jet and the adjuster limits, I figured it was to run leaner to limit emissions


:chainsawguy:

 

[COWBOYJAKE]

I have been topped out on the H screw and the saw still runs more on the lean side than I would really like it to. I want to mod the muffler and I am afraid if I do I wont be able to get more fuel to it

 

[mtngun]

I have been topped out on the H screw and the saw still runs more on the lean side than I would really like it to. I want to mod the muffler and I am afraid if I do I wont be able to get more fuel to it

Topped out on the limit tab ? Then get rid of it.

I have no experience with that particular model, but most saws have plenty of adjustment on the H screw once the limit tabs have been removed.

 

[komatsuvarna]

Topped out on the limit tab ? Then get rid of it.

I have no experience with that particular model, but most saws have plenty of adjustment on the H screw one the limit tabs have been removed.

+1, If you cut the tabs you should have plenty of adjustment.

 

[COWBOYJAKE]

Well I have the carb apart due to needing new pump and seals. It looks like it was pressed in from the outside. Does the carb need to be warmed to get it to come out it looks like an interference fit

 

[longbar]

I just cut the little interference tabs off and leave the rest of the plastic cap on my adjustment screws.

 

[sunfish]

You do not need to change the jet on a 346xp.

 

[blsnelling]

You do not need to change the jet on a 346xp.

What he said.

 

[Tzed250]

I bought a non kalifornia main jet for my 346xp, I figured I could get a bit more fuel and hp out of it with this jet. And while I have things in pieces I am going to file off the adjuster stops. I can not seem to figure out how to get the main jet out. how do I get it out??

Thanks!

Jake

This may or may not be of some help:

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A few weeks back there was a discussion about the high speed jet, called the fixed jet in a Stihl IPL, and its role in tuning the carburetor.

A little research shows that the US bound MS660s are equipped with a Walbro WJ-69 carb. The IPLs that I have show a .64 jet as standard, with a .62 jet optional for high altitude operation. After porting my 660 I found that the H needle needed to be 1.25 turns out to get the saw to four-stroke. I figured a new jet was needed. I ordered the 1122 121 5607 .74 fixed jet from the dealer. This jet is found in the WJ-76 carbs found on saws not headed for North America.

When I disassemled the carb I found a somewhat unpleasant surprise. The saw had been shipped with a .62 jet. EPA strikes again.

I thought I would share a quick how-to for replacing this jet.


1. Remove the carb and orient the top toward you.

<a href="http://www.flickr.com/photos/41385771@N03/5196813864/" title="top by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4087/5196813864_739d8513e4_b.jpg" width="1024" height="819" alt="top" /></a>


2. Remove the top cover. This will expose the fixed jet. It is the slotted brass part below the lever.

<a href="http://www.flickr.com/photos/41385771@N03/5196214377/" title="62 by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4086/5196214377_24bd00603b_b.jpg" width="1024" height="819" alt="62" /></a>


3. Remove the fixed jet. Be sure to use the correct size screwdriver as brass is soft and unforgiving.

<a href="http://www.flickr.com/photos/41385771@N03/5196215083/" title="driver by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4071/5196215083_bef930bb14_b.jpg" width="1024" height="819" alt="driver" /></a>

4. This is the new jet to install. The jet number is stamped on top.

<a href="http://www.flickr.com/photos/41385771@N03/5196815358/" title="new by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4131/5196815358_83c24c1d4e_o.jpg" width="762" height="610" alt="new" /></a>



5. The new jet in place. Reassemble the saw then tune as usual.

<a href="http://www.flickr.com/photos/41385771@N03/5196816190/" title="74 by zweitakt250, on Flickr"><img src="http://farm5.static.flickr.com/4083/5196816190_86042fa91f_b.jpg" width="1024" height="819" alt="74" /></a>





After the .74 jet was installed my 660 now four-strokes with the H needle 7/8 of a turn out. That is how it should be.


Thanks for looking!


.