what IGNITION SYSTEM would be the better combo for a 550xp MK1 or 2 build

[dangerousatom]

Looking for some quick advice on a 550xp build, particularly the coil difference.

I do not have a lathe so I am not looking to do any major machine timing changes to the cylinder. Only a gasket delete and some porting/cylinder clean -up.

I have both saws on the shelf to scavenge from, but im looking to figure which ignition system will play best with witch cylinder/crank/piston. I was thinking the MK2 cylinder and piston with MK1 case, coil and carb...? There seems to be very little evidence of anyone swapping a MK2 cylinder and piston on to a MK1, so I assuming its not possible or worth the time vs the benefits ...if any

-I know the cylinders and pistons are different, I assume its the port timing.
do the two saws have different crank lengths? or is one piston taller? Id like to keep the MK1 stuffers and use that case assembly for the build.
-I think from research the coils for either saw have different RPM and the MK1 is higher rpm.
Id assume the MK1 is better for the stuffer crank.

 

[redneckhillbilly]

please do a build thread and post lots of pics.

 

[dangerousatom]

LoL
Well see what comes of it, depending on the pending recommendations.

I have a feeling the swap is not worth the benefits when both saws are close in performance.

IMO the MK2 changes were made to lower the "Joe Homeowner" thermal warrantee/bearing issues and hot start troubles.
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[redneckhillbilly]

I had a 545 mk1 and i liked it alot, i also had a 550mk2 and the mk1 was noticeably lighter and seemed higher strung.

the mark1 had alot better balance and overall feel.

 

[dangerousatom]

Yes those are the main reasons Im after a highbred build if possible.

From the few autotune porting's Ive done it seems the RPM always goes up after its been retuned, but still seems to be held back in the cut. Ive always wished the service tool software access would let you bump the RPM to a higher max setting...even if it flagged your carb cereal# and voided the warrantee.
If i had millions of dollars Id pay a savvy computer code reader hacker to figure a work around to be able to adjust the fuel curve and RPM like tuning cars on a dyno.
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[srcarr52]

You may be getting some things confused with the 562 MK2 which had changes more detrimental to it's power output than the 550 MK2.

A lot was changed on the cylinder and case between the original 550XP and the MK2. I doubt the MK2 cylinder will bolt to a MK1 case well as they changed the transfer port design and added pins to locate the cylinder. Also the intake manifolds are different.

Both version have crank stuffers and might even share the same crankshaft.

MK1 autotune is slower to tune but has the rev boost feature if Husky didn't turn that off with software updates at sometime. I don't know if they did, but I could see them removing it to try to increase bearing life.

MK2 is a different generation of autotune which tunes in very fast and seems to start more reliably.

For a ported work saw they both come out relatively the same as far as power. MK1 feels more nimble to use than it's thicker brother but the MK2 starts better and has a better air filter that won't fit under the MK1 hood.