Meteor MS661 kit port timing

[stihl_problem]

I bought the Meteor MS661 cylinder/piston kit. Has anyone done port timing numbers or dyno numbers to see how good or bad this aftermarket kit is? My old cylinder is scored beyond repair so I can't use that. It's my first post on Arborist Site and I wanted to thank you all for helping me many times on my other saws.

 

[huskihl]

I would hunt for a used OEM cylinder. Hyway and meteor 661 cylinders run about 70% the speed of an OEM cylinder

 

[stihl_problem]

I would hunt for a used OEM cylinder. Hyway and meteor 661 cylinders run about 70% the speed of an OEM cylinder

Thank you for for the input, it's pretty much what my gut told me. Do you think the Meteor piston and Caber rings are worth keeping or just get an OEM kit?

 

[huskihl]

Thank you for for the input, it's pretty much what my gut told me. Do you think the Meteor piston and Caber rings are worth keeping or just get an OEM kit?

Meteor pistons and the Caber rings they come with are near oem quality. Rings may be better than oem.

 

[huskihl]

Are you certain your cylinder is scrap?

 

[stihl_problem]

Are you certain your cylinder is scrap

I assumed since it had vertical scoring that some casual scotchbrite buffing wouldn't remove. Should I ball hone it first to see if they come out? Do you have any sugestions for ball hones that would work on this sized cylinder?

 

[huskihl]

I assumed since it had vertical scoring that some casual scotchbrite buffing wouldn't remove. Should I ball hone it first to see if they come out? Do you have any sugestions for ball hones that would work on this sized cylinder?

I use muriatic acid and sandpaper. I’ve never used an actual hone on a cylinder. I’ve seen too many where others have used them that are missing plating around the ports. It’s not necessary.

Acid dabbed on a Q-tip will eat the aluminum. Sanding between applications seems to freshen up the aluminum so that the acid can work better next time

 

[Mad Professor]

I use muriatic acid and sandpaper. I’ve never used an actual home on a cylinder. I’ve seen too many where others have used them that are missing plating around the ports. It’s not necessary.

Acid dabbed on a Q-tip will eat the aluminum. Sanding between applications seems to freshen up the aluminum so that the acid can work better next time

I do similar. But a rinse and dish detergent with wetdry between acid applications.

Keep the acid off the port edges. If the marks bubble with the acid it's aluminum transfer.

 

[Gord404]

used to use acid until I saw Mastermind's vidio, been cleaning up transfer that way for a number of years, and be carful around the ports - works well for me-IMO

 

[J D]

+1 for cleaning up your OEM cylinder... it's amazing what "damage" you can remove sometimes as it's really all transfer. Worst case scenario you should be able to clean up the original well enough to get the timing numbers off it & compare to your new cylinder.
Meteor would have to be one of the best aftermarket options so you may well find it doesn't take much tweaking to get it to where you want it

 

[Gord404]

+1 for cleaning up your OEM cylinder... it's amazing what "damage" you can remove sometimes as it's really all transfer. Worst case scenario you should be able to clean up the original well enough to get the timing numbers off it & compare to your new cylinder.
Meteor would have to be one of the best aftermarket options so you may well find it doesn't take much tweaking to get it to where you want it

yes I use them quite often, just got to be careful when porting- easy does it- found a 372xtorq cylinder in a saw shop dumpster at my local saw shop- took it home and cleaned up- like new

 

[stihl_problem]

I did want to follow up and say I tried to get all the transfer off but the scratches were too deep. I ended up buying the OEM Stihl cylinder/piston kit. Should I assume that I need to check the gap on a factory kit (matched piston, rings, and cylinder)? Lastly, the crosshatching doesn't seem very significant which sort of has me worried that the rings aren't going to seat properly. What are your thoughts on the ring gap and crosshatching. Oh and I bought it from the local Stihl dealer, sealed in the box.

 

[huskihl]

I did want to follow up and say I tried to get all the transfer off but the scratches were too deep. I ended up buying the OEM Stihl cylinder/piston kit. Should I assume that I need to check the gap on a factory kit (matched piston, rings, and cylinder)? Lastly, the crosshatching doesn't seem very significant which sort of has me worried that the rings aren't going to seat properly. What are your thoughts on the ring gap and crosshatching. Oh and I bought it from the local Stihl dealer, sealed in the box.

Crosshatching isn’t needed. All newer Stihl cylinders are smooth like that

 

[stihl_problem]

Crosshatching isn’t needed. All newer Stihl cylinders are smooth like that

do you double check the ring gap on an OEM kit?

 

[Gord404]

I usually check all rings before I put them in- put a set of cabers on an oem cyliner and piston to push down a bit to make sure its sitting streight and the gap not over a major opening- a feeler gage make sure the gap is what i want - this was on a MS660

 

[huskihl]

do you double check the ring gap on an OEM kit?

Yes

 

[stihl_problem]

I did want to reach back out to this forum and thank everyone for their input and time. Before I had checked out your responses about the rings I contacted Stihl customer support and they did verify that ring gaps are checked at the factory to the matching cylinder since you buy it as a set. I hope that helps someone in the future. To add value to what @huskihl and @Gord404 said, it's always best practice to verify the ring gap; trust but verify. Thanks again!