Flywheel Idea

[slackinoff]

I wanted to try something as an experiment and fun.

The 61, 268, 272, ect saws all seem to be just a bit sluggish on revving up and also down. Porting and ignition timing has helped on mine yes. But compared to my other saws it's not nearly as snappy. Watching videos, these all seem to be a bit slow coming up.

Anyways, I wanted to experiment with machining down some of the flywheel. See pics. I want to take down that outer ledge and a bit of the inner part of the fins so it matches the machined down ledge. It won't be a lot of weight, but with it being on the outer edge, it will make the most difference.

I realize this does nothing for real world performance, this is just for my entertainment and satisfaction. And that's the only reason I need.

 

[Philbert]

Interesting idea. Just remember that flywheels sometimes explode.


Philbert

 

[Ronie]

I don't think it would hurt anything and it might help, I did the same thing on my 036 and 440 hybrids for clearance.

440 flywheel

 

[slackinoff]

@Philbert - yes, but.....this one doesn't have the burst warning label on it.

 

[slackinoff]

I don't think it would hurt anything and it might help, I did the same thing on my 036 and 440 hybrids for clearance.

440 flywheel

View attachment 333434

Nice work! That's right, I knew I had seen guys do that to some hybrids.

Did you do that yourself, looks great? Not sure if you want to, but I am looking for someone to do this one for me. I'd gladly pay you.

I have one person I have reached out to, if I don't hear back from them and you want to, I'd be happy to send it.

 

[Ronie]

Nice work! That's right, I knew I had seen guys do that to some hybrids.

Did you do that yourself, looks great? Not sure if you want to, but I am looking for someone to do this one for me. I'd gladly pay you.

I have one person I have reached out to, if I don't hear back from them and you want to, I'd be happy to send it.

Thanks, I did that one on the late and the 036 one I just used a flap disc. I don't think I'm qualified to do machine work for other people, I screw up way to much. If you have a drill press you could run a bolt through the flywheel, mount it in the press and use a flap or grinding disc. On the 036 one, I just held it in my hand and ground it down.

036 flywheel

 

[Ronie]

I was just looking at a couple of my 2 series videos and to me they don't seem sluggish off idle and come right down after the cut.

 

[timg]

Just another idea for you @slackinoff.
Some of the Jonsered 600 series had two different flywheels with key slot to magnet positioning. I still have found no rhyme or reason for this. Only thinking out loud maybe due to the series 2 625.630's. Anyhow it's another experiment without machining. I will add with the wrong coil//flywheel combo they have a hard time getting up to speed.

 

[Ronie]

Just another idea for you @slackinoff.
Some of the Jonsered 600 series had two different flywheels with key slot to magnet positioning. I still have found no rhyme or reason for this. Only thinking out loud maybe due to the series 2 625.630's. Anyhow it's another experiment without machining. I will add with the wrong coil//flywheel combo they have a hard time getting up to speed.

The Husky's also don't run to good with the wrong flywheel.

https://youtube.com/shorts/9Sb3Czg-Ils

 

[slackinoff]

@Ronie you are right. I went back and watched some of my first videos after porting and the saw jumps off idle better back then. Revs just as good as yours.

It must not have had that minor air leak when the first few times I ran it. I didn’t have a pressure vac tester back then so I’m not 100% sure.

I’m guessing a lot of theses saws have air leaks when I watch the videos and they are sluggish. The intake block design is troublesome for air leaks and cracks.

My 61 is halfway into vid

 

[huskyboy]

The intake block design is troublesome for air leaks and cracks.

I wouldn’t say it’s a bad design. Just not as good as a intake boot for isolating the carb from the engine heat. I haven’t seen a intake boot last 30 years either. I think they are failing mostly due to age and wear/tear (vibration). Nothing lasts forever. Especially rubber and plastics.

 

[slackinoff]

I just looked at my cylinder. This probably is another reason it doesn’t run the same. Plating has worn away. Same situation in the upper part near the combustion chamber.

 

[Mastermind]

I just looked at my cylinder. This probably is another reason it doesn’t run the same. Plating has worn away. Same situation in the upper part near the combustion chamber.


View attachment 333476

View attachment 333477

Making your intake port too large is not a great idea if a snappy saw is the objective.

 

[slackinoff]

Making your intake port too large is not a great idea if a snappy saw is the objective.

Thank you. I was careful to not hog it out when grinding to my number. You and some others gave me that advice in my build thread before I ported it.

You can see in the video it was pretty snappy after porting....somewhere between then and now it lost that snap. I fixed some pressure leaks, but something was still up. The plating was not like that after I ported it.

Here is the picture right after porting, before I ran it. The plating looks a ton worse in that area and others now it has been ran about 3 -4 gallons.

 

[slackinoff]

Edit

 

[slackinoff]

Still up in the air about what cylinder I am going to put back on this one but, I tried my hand at taking some weight out of the flywheel.

@Ronie - I gave your idea a try. Turned out well. Compared to another 61 flywheel I have, it’s 30 grams lighter. Which is almost 10%.