MS180 Adjustable Carb

[Trigger-Time]

Nope I did get permission from the doc today to start ramping up my activites within reason.

..........is running a SAW within reason?...even if it's a 180!

I put mine together last night & cut some with it before work.Seamed to cut verey good.I'll do a mufler mod tonight or tomarow then check it

Will be waiting for the report





Gary

 

[blsnelling]

I finally had a chance to run mine tonight. It's running great and it's nice to have control over WOT tuning. One little tuning issue. I had to richen up the low side to get good throttle response until I can barely get the idle speed high enough to idle. When the low needle is set at a point where the idle speed is easily adjustable, it's too lean and bogs when opening the throttle. I finally got it at a point where it's accelerating well but barely idling fast enough. Any ideas how to correct this slight "characteristic"?

 

[PES+]

Yup

Take off the intellicarb chamber cover and go back to the cover that came with the carb.

You will need to block the hole in the air filter or change out the filter with a non intellicarb port.

 

[blsnelling]

You saying that will affect the low speed mixture and idle speed? Can you explain in a little more detail for my understanding?

 

[Lakeside53]

The intellicarb port has not effect if not into the filter. Take off the filter if you think there is an issue with that end.

I'm betting your venturi is too big for the idle air volume, and your transition bores are not matched to the 180.

 

[pgg]

tweak the fuel tang and see what happens

 

[blsnelling]

I'm betting your venturi is too big for the idle air volume, and your transition bores are not matched to the 180.

It appeared to be the same size as the previous carb. Maybe I'll take it off and measure it, because that did cross my mind.

 

[lectrocrew]

I got my WT-215 carb installed this morning and it fit fine except I had to tweek the throttle linkage a little to get full WOT just like you did Brad. Since the 018c has no intellicarb everything fit like it was factory. I haven't cranked it yet. I will take the saw to work with me tonight to drill the screwdriver passages for the adjustment screws. I'll probably crank it in the morning and cut some wood along with setting the adjustments. I'll post the results afterward.

 

[blsnelling]

I think I'll try removing the Intellicarb cover. It enters the air box on the dirty side of the filter, so I don't even have to worry about plugging the hole.

 

[Lakeside53]

Are you sure? If it's on the dirty side, it has no effect... that's atmospheric pressure.


Wabro's web site will show you the venturi size of the 215. Not sure if zama does.. and it has litle meaning to compare them as a carb is balance of jet size/venturi. Look up the WT325 and compare it to the 215 - the 325 was originally on the 170 - it might give you a few clues if there's any difference.

I've swapped a lot of "similar" small carbs around mainly to get oddall saws/blowers working again, and never really had much problem at the top end -either just tune it or change a jet. Most probloms are as your describe - low idle/accel, and that's a pita to fix - usually I just gave up and dug deeper in the junk draw for the "righ" carb.

 

[Trigger-Time]

Are you sure? If it's on the dirty side, it has no effect... that's atmospheric pressure.


Wabro's web site will show you the venturi size of the 215. Not sure if zama does.. and it has litle meaning to compare them as a carb is balance of jet size/venturi. Look up the WT325 and compare it to the 215 - the 325 was originally on the 170 - it might give you a few clues if there's any difference.

I've swapped a lot of "similar" small carbs around mainly to get oddall saws/blowers working again, and never really had much problem at the top end -either just tune it or change a jet. Most probloms are as your describe - low idle/accel, and that's a pita to fix - usually I just gave up and dug deeper in the junk draw for the "righ" carb.

Lake IYO, What would be a good carb for this application? (WT325 you spoke of)
I would like to upgrade the carb on my 180 also. Not so much that it needs it,.............just want to.


Gary

 

[PES+]

Brad....can you post some pics? I have never seen an intellicarb that did not reference the interior of the air filter as that is how it works.

Now for the big argument maker....there is no intellicarb that does not use an accelerator pump of one sort or another.

About as big a hint as I can give you.

Too bad the big bad EPA made you so anti logical.

This question is for Andy/Lakeside ONLY (LOL fish meister it wouldn't let me rep you for that one)
What does a 200T with a bad accelerator pump run like most often if the pump is jammed so fuel does not flow?

 

[blsnelling]

Brad....can you post some pics? I have never seen an intellicarb that did not reference the interior of the air filter as that is how it works.

I believe I was mistaken when I made that comment. It plugs into the filter housing body in the intake plenum, but seperated from the main air flow by a baffle. The connection is below the filter but is open to the filtered section.

 

[blsnelling]

The WT325A does not have a H needle on it, so it's not an option if you're after WOT adjustment. That's what I just took off this saw. It runs a hair richer than the original Zama which had no L adjustment either. I ran the WT325A with my muffler mod. I'm planning on porting this saw, thus my quest for a fully adjustable carb.

I just came from the garage where I removed the Intellicarb cover and reinstalled the original flat cover. I plugged the hole in the filter housing with a rubber plug. With the Intellicarb cover, I had the L needle at 1 3/4 turns out to get good throttle response. I'm now at a more reasonable 1 1/4 turns and have good control over the idle speed and excellent throttle response. I've yet to cut wood with it, but initial results are promissing.

I measured the bores of the three carbs. The original Zama is actually the largest at 0.631". Both Walbros, WT325A & WT215, have a 0.627" bore. So it's not from having too little velocity due to a larger bore. I'm guessing the Walbro just doesn't like the Intellicarb cover since it didn't come with one. I'm only guessing.

Pes+, thanks for the tip. It looks like it worked. More testing to follow once I get it in some wood again.

 

[Trigger-Time]

Your doing good their, Brad

I have a 215 carb.......I'm just waiting on you to get all the bugs worked out before I proceed with mine .......kinda of chicken sh!t, of me.

Gary

 

[blsnelling]

If you don't want to plug the Intellicarb port in your filter housing, it looks like you can buy a 018 housing without the port, PN 1130 140 2804. The 017 IPL has it listed as a 1130 140 2803. I'm not sure what would be different.

Can anyone tell me what PN 1130 124 7100 is for? It's item #11 on page 8 of my MS180 IPL.

 

[blsnelling]

Your doing good their, Brad

I have a 215 carb.......I'm just waiting on you to get all the bugs worked out before I proceed with mine .......kinda of chicken sh!t, of me.

Gary

Just do it!

1. Remove the brass plug from the impulse passage on the rear face of the WT215.
2. Plug the original passage with JBWeld or something similiar.
3. Install the carb. Do not use the Intellicarb cover from the original carb.
4. Block the hole in the filter housing where the Intellicarb port inserted.
5. Drill holes in the plasic for access to the screws.
6. Install a small screw behind the throttle linkage, blocking the slot, so that linkage will have enough travel to go WOT. Do not bend the linkage or the carb may not fully return to idle.

[/LIST]

 

[Lakeside53]

Brad....can you post some pics? I have never seen an intellicarb that did not reference the interior of the air filter as that is how it works.

Now for the big argument maker....there is no intellicarb that does not use an accelerator pump of one sort or another.

About as big a hint as I can give you.

Too bad the big bad EPA made you so anti logical.

This question is for Andy/Lakeside ONLY (LOL fish meister it wouldn't let me rep you for that one)
What does a 200T with a bad accelerator pump run like most often if the pump is jammed so fuel does not flow?

No arguement can be made... Very very few Stihl Intelli-carbs use any form of accelerator pump... I'm hard pressed to name more than the 200T and 200 (saws)


The question - usually - you get a lag in acceleration, and as it it gets worse, it just won't accelerate. Often, it''s intermittent.. . And... sometimes you get what seems like a failing seal - revs up and quits.

 

[Lakeside53]

I measured the bores of the three carbs. The original Zama is actually the largest at 0.631". Both Walbros, WT325A & WT215, have a 0.627" bore. So it's not from having too little velocity due to a larger bore. I'm guessing the Walbro just doesn't like the Intellicarb cover since it didn't come with one. I'm only guessing.

.

You cannot compare bores directy on the Zama and Walbro carbs, or carbs from different families - it's a balanced system... many ways to skin a cat (as to put it....).

The intelli cover should make no difference unless it just didn't fit correctly.

 

[Trigger-Time]

No arguement can be made... Very very few Stihl Intelli-carbs use any form of accelerator pump... I'm hard pressed to name more than the 200T and 200.


.

accelerator pump......what about 361...........just what I read in manual.


Gary