Ported 2172 carb tuning

[Ronie]

I pick up a 2172 and yesterday I started porting it. I got it all roughed in, put it on the saw and my port timing is, exhaust 98, transfers 120, intake 78. The dividers in the intake track have been removed, intake on the cylinder has been angled down towards the bottom, lower transfers case matched and opened up a little, base cut and a pop up piston was made, exhaust widened to 34mm. On my exhaust sweat was dripping on my glasses and I accidentally cut to large of a bevel, so with the bevel my exhaust is 96. When I saw that, I decided to just put it on and see how it runs, if it was ok I could pull it back off and smooth everything out. I got it together and it runs great but to get it running right I'm around 1 1/2 to 1 3/4 turns out on the lo and high and it's still turning a little over 15,000 rpm wot. I've only made a couple of cuts n some small wood and ran out of fuel. What concerns me is that I had to turn the carb screws out so far to get where its at now. Should I be worried or should I richen it up some more to get the rpm down?

 

[cuinrearview]

Give it more fuel

 

[Ronie]

Give it more fuel

After lunch I'll get some gas and see how it acts with some more fuel.

 

[huskyboy]

It’s somewhat normal to be that far out on the jets with a RWJ. Keep the XT around 13,500. There is a reason why they have a limited coil. The p/c is heavier than the OE.

 

[cuinrearview]

You could always ditch the strato top end and throw your Ebay OE kit on there. Last I looked still only $106.

 

[beaglebriar]

Personally I think the exhaust is too wide and gutting the strato is the wrong way to go. 15000 is way too much rpm for an xtorq saw.

 

[Ronie]

It’s somewhat normal to be that far out on the jets with a RWJ. Keep the XT around 13,500. There is a reason why they have a limited coil. The p/c is heavier than the OE.

I'll take it down to 13,500

 

[Ronie]

Personally I think the exhaust is too wide and gutting the strato is the wrong way to go. 15000 is way too much rpm for an xtorq saw.

I'm not keeping it that high, it's just where it's at now.

 

[cuinrearview]

Personally I think the exhaust is too wide and gutting the strato is the wrong way to go. 15000 is way too much rpm for an xtorq saw.

You probably like vanilla ice cream and well done steak too don't ya?

 

[Ronie]

You could always ditch the strato top end and throw your Ebay OE kit on there. Last I looked still only $106.

If it fails, I've got one I could put on it. They are so cheap now I wish I could afford to buy a few.

 

[beaglebriar]

You probably like vanilla ice cream and well done steak too don't ya?

Negative... strawberry and medium rare please.

 

[Ronie]

Here's some pics of the cylinder. I haven't smoothed anything out yet and it's not pretty. If it ends up being a good running saw I'll take it back off and shine it up.

 

[Ronie]

It's good to know that it's normal to have the jet so far turned out with these carbs. I was a little worried, I've never had a saw richened up like that and still be screaming. Thanks for everyone's help and I'll keep updating until I get it finished.

 

[Ronie]

Well I turned it down to 13,560 and it's running real good. I need to get some bigger wood to tune it right. after I get it right the blue coil will be going back in it to keep it at a safe rpm. It's to hot and humid to mess with it anymore today. Thanks again everyone.

 

[huskyboy]

Good deal. You can keep unlimited on it if it makes it easier for you to tune. Just don’t spool her up too high. Unlimited always makes it easier to tune for me personally.

 

[beaglebriar]

I like the 14,100 346 coil in these. You can turn them up a little bit, say to 13,800 and still be safe. The higher rpm limited coil allows for easier tuning and still offers some protection.

 

[huskyboy]

I’m not sure what it is exactly that kills the crank... excessively high rpm with the heavier piston or the lean tune. Probably a combination of both?

 

[cuinrearview]

I’m not sure what it is exactly that kills the crank... excessively high rpm with the heavier piston or the lean tune. Probably a combination of both?

That's a heavy piston...

 

[Ronie]

I made a test cut a few minutes ago and I'm happy with the way it turned out. Feels fast and strong. I think it's a little rich on the low and high. Should I lean it out some more?

 

[cuinrearview]

Looks like it might be a little fat at idle, but idk how much you ran it before the vid. Cleaned up nice under load.