2150/350 to 346xp OE Conversion

[Gvsu141]

I recently picked up a nice Jonsered 2150. Decent running with the standard intake leak & cylinder fins smushed up pretty good. Piston and cylinder wall in good shape. Thinking on doing the conversion due to the damage on the fins.

I have a nice extra 42mm OE 346 top end. Would just need a new ring. Everything I see shows the conversion done with the 44.3mm NE. Will the smaller OE a good conversion? Or should I buy a NE kit?

Would I be better off using the carb off the 2150? Or the carb off the OE 346? Or does it matter? I have both ready to go.

2150 carb is a Zama C3 EL18 46A
346xp carb is Zama C3 EL18 27A

 

[Dolkitafreak]

42mm will work great, carbs will interchange fine, both are EL18 so one isn’t really better than the other as far as I recall.

 

[Spike60]

Since you already have it, might as well use the 42mm kit. Not so much the carb, as the coil from the 346 that you might want to use. The 2150 looks to be a later model, and probably has the blue/limited coil. 42mm 346 should have the black/unlimited coil.

Remember to take about .050 off the cylinder bolts. Cylinder flange on 346 jugs is thinner than on the 350/2150 kits. Which is why I love this build, and why these conversions run so good.

 

[farminkarman]

A few months back I built a 350 with a 346oe cylinder. I used the 346 intake boot, 350 carb, and 357xp air filter holder & filter. I machined and ported that one, and it was a beast. That being said, I would probably use the 2150 carb. As Spike said, I would use a black coil with the 42mm top end.

 

[Kiwioilboiler]

And try and use a late model riser that has fine threads to secure both it to the plastic case, and also the cylinder to the riser. Early models had coarse threads both sides. Middle age models coarse lower, fine top which are also serviceable, but not the best.

 

[Gvsu141]

Since you already have it, might as well use the 42mm kit. Not so much the carb, as the coil from the 346 that you might want to use. The 2150 looks to be a later model, and probably has the blue/limited coil. 42mm 346 should have the black/unlimited coil.

Remember to take about .050 off the cylinder bolts. Cylinder flange on 346 jugs is thinner than on the 350/2150 kits. Which is why I love this build, and why these conversions run so good.

Thanks! The coil looks to be the 537162104 black coil. Otherwise I should have one from the 346 - Have pretty much an entire 346 OE to use as a parts saw with a bad case.

Good reminder on the cylinder bolts. Do you just machine the impulse port in the riser enough to clear the cylinder?

 

[Gvsu141]

I used the 346 intake boot, 350 carb, and 357xp air filter holder & filter. I machined and ported that one, and it was a beast. That being said, I would probably use the 2150 carb.

Thanks. Sounds like a plan. I'd love to get into porting, but this won't be the one to start with. I'll probably MM it, and optimize the squish with a new ring.

 

[Spike60]

No need to mess with the impulse port, it works fine. The muffler mod is all you'll need to mess with. It'll rip.