Experts Needed - Husqvarna 445 - Run 3/8" x .50 Chain with Sprocket & Drive Change?

[dsell]

The 108215X sprocket (small spline) and 18720 (3/8 x 7) rim arrived. The good news: This combination almost gets me where I want to be. 3/8 x .050 x 72DL with a 20" narrow tail bar. The bad news: As dsell warned, it seems another oil pump gear is needed. The teeth on the spline are a too small for the oil pump pinion gear as we suspected. It works and the saw oils fine but I worry that since there is so much play in the fit that reliability may be a problem. Have the 503892103 gear ordered. If that fits the saw and fits the spline we're in business!

View attachment 239023

Thanks for the picture and glad it's working out for you. Hope you post another picture with the new gear.

 

[SawTroll]

I use freezer bags with yellow and green index cards (semi vs safety chains, easy to spot). Big number for chain length and the saws # on the flip side.

My 3 saws (5 bars) and the electric pole saw do not mix. It is NOT a pain unless I get lazy.

View attachment 239062

 

[nmurph]

Linky no worky...:msp_confused:

 

[computeruser]

That saw would be at its best running 13-15" bar and .325" chain. I would not switch that one to 3/8", even though I understand and appreciate your argument in favor of parts commonality. I tried that whole commonality game a while back and found it to be more work than it was worth for me. Sadly, I sold off saws that didn't "fit" in the common bars/chains plan, and now regret having done so, since the commonality thing didn't really give me nearly as much benefit as I had figure it would.

 

[KCOLC]

End of the Road?

The 108215X sprocket (small spline) and 18720 (3/8 x 7) rim arrived. The good news: This combination almost gets me where I want to be. 3/8 x .050 x 72DL with a 20" narrow tail bar. The bad news: As dsell warned, it seems another oil pump gear is needed. The teeth on the spline are a too small for the oil pump pinion gear as we suspected. It works and the saw oils fine but I worry that since there is so much play in the fit that reliability may be a problem. Have the 503892103 gear ordered. If that fits the saw and fits the spline we're in business!

View attachment 239023

Well...looks like we may have reached the end of the road with regard to finding an oil pump dive gear for the 445 that gives a perfect fit to a small spline sprocket. The 503892103 gear that arrived fits the sprocket spline perfectly but the inside diameter is too large for the 445's shaft and the outside diameter is too large to engage the oil pump properly even if a bushing were used to correct the ID. So...unless there are any more ideas it seems the best combination we have found is the standard 503931801 oil pump gear which is a loose fit but to this point works fine, the 108215X sprocket and the 18720 rim. Note that the attached photo shows both gears. The black gear is the stock 503931801. The hole in this gear appears to be worn or elongated. It's isn't. Just the camera angle that makes it appear that way.

 

[dsell]

Thanks for the update and picture.

 

[KCOLC]

Thanks for the update and picture.

Thanks for the help and effort in getting me this far!

 

[SawTroll]

I try again;


View attachment 239410

The pic is old, and I mark the boxes (soft plastic) a little different by now (chain model and dl count). Two chains fit in each box, up to at least 24" chain.

 

[KCOLC]

I try again;


View attachment 239410


The pic is old, and I mark the boxes (soft plastic) a little different by now (chain model and dl count). Two chains fit in each box, up to at least 24" chain.

Great idea which I'll use for spare parts too. Have everything in plastic bags and all in one box. Your way is better.

 

[MMG]

:arg:

Does the 445 have an umlimited coil or should I tune it with a tach?

 

[KCOLC]

UPDATE on Husqvarna 445 running 3/8" X .50 Chain

Thought I would check in with an update on this combination. Have been cutting with this saw on a regular basis since may. Mostly red and white oak and birch and occasionally some poplar. Diameter is up to 12"-14" anything larger and I use the 266. Saw is running fine, oils well. No issues with regard to cutting performance as long as the reduced power (as compared to the 266) is kept in mind and I don't get overly aggressive when using the bucking spikes. Exhaust has NOT been modified. Overall this was a good move for me. The reduced weight and ease of starting make me want to make this saw the first one I reach for. One thing I am finding with the 445 is that it has a tendency to want to kickback much quicker than the 266 does. With the 266, which I've run for more than 20 years it's almost never an issue. I'm assuming with the 445 this is due to the saw being lighter?? Am I right on this or is the chain and bar length on this saw causing that issue? Not sure as my experience with saws is limited to the 445 and 266.

 

[horizon92]

Help! I was recently given a stock Husky 445 (.325 x 50). Have already have a Husqvarna 266 (20" bar) with which runs 3/8 x .50 chain. It has a stock 7T sprocket. I have so many chains for 266 that I would like to run the same chain on the 445 too so I can keep life simple and avoid confusion. I realize, IF THIS IS POSSIBLE, that I will need to change the 445's sprocket, bar and possibly the clutch too. Has anyone here done this? I'd be very grateful if someone can tell me what needs to be done and what parts are needed and who has them? My dealer, who has carried Husqvarna for a very long time was clueless. Put a call in to Bailey's on Friday morning but they have not returned my call. My guess is the knowledge I need exists here! Not worried about stressing the 445. It won't be used to cut anything larger than about 6 to 8" I'm over 6' and the 20" bar is easier on the back. Many thanks!

I have read some of the reviews. im am no expert. il share some knowledge, the older 445 has a 46cc engine. the new one that i own has a 50cc engine, a 2011 445 with i believe is identical to the engine in the 450. i dont know if the older smaller 445 shares the same size crank but i swaped oil pumps out for one from a 353 or a 346 worm drive and pump my 353 has a rim sprocket and u can get a 3/8 pitch 7 pin standard rim sprocket for to swap with the .325 rim sprocket. if u can confirm that the shafts are the same size theres half of ur issue solved i can get parts from the 353 or the 346xp i dont know much about the bars. and i agree if u have the smaller 445 that its gonna struggle pulling that chain that long u can keep depth gauges and angles high on the chain that will help a bit not much but also so to point out that 3/8 chain has less cutting teeth and it technically takes less power if the bars were the same previous length. 3/8 chain is heavy and thicker so its hard on a saw thats already under powered. but do what u want its worth a try if u think its gonna work for you i didnt read all the reviews so i dont know if u got the answer u were looking for

 

[horizon92]

I have read some of the reviews. im am no expert. il share some knowledge, the older 445 has a 46cc engine. the new one that i own has a 50cc engine, a 2011 445 with i believe is identical to the engine in the 450. i dont know if the older smaller 445 shares the same size crank but i swaped oil pumps out for one from a 353 or a 346 worm drive and pump my 353 has a rim sprocket and u can get a 3/8 pitch 7 pin standard rim sprocket for to swap with the .325 rim sprocket. if u can confirm that the shafts are the same size theres half of ur issue solved i can get parts from the 353 or the 346xp i dont know much about the bars. and i agree if u have the smaller 445 that its gonna struggle pulling that chain that long u can keep depth gauges and angles high on the chain that will help a bit not much but also so to point out that 3/8 chain has less cutting teeth and it technically takes less power if the bars were the same previous length. 3/8 chain is heavy and thicker so its hard on a saw thats already under powered. but do what u want its worth a try if u think its gonna work for you i didnt read all the reviews so i dont know if u got the answer u were looking for

sorry not a standard a mini or small they call it

 

[KodiakII]

I was told by the dealer that my 555 would pull a .325 better than 3/8...I went with the 3/8 anyways...and am not disappointed. BTW my 266 runs .058, just saying...maybe they were different up here.

 

[outdoortype]

l

I was told by the dealer that my 555 would pull a .325 better than 3/8...I went with the 3/8 anyways...and am not disappointed. BTW my 266 runs .058, just saying...maybe they were different up here.

I bet the dealer was right. The .325 is displacing less wood (thinner kerf) so this wood mean less resistance. Also a .325x7 gear is smaller in diameter so therefore delivers more torque. The .325 chain itself is probably lighter. It's a tough comparison to make because the only equal bar length is the .325x72 18" and the oddball 3/8 x 64-18". Most people that want to switch to .325 on a 555 sized saw will do so to run longer bar lengths 20" or so.

 

[HuskStihl]

Here's an update. Starting with the advice I received here on the Oregon 108565X (3/8 x 50) rim sprocket as a possibility, it appears I can add a matching Oregon ORF11893 bearing and the 2000RNDK095 Power Match bar ( 20" x 3/8 x .050 x 72DL, small tail ) and I'm where I want to be. A caution that many here advised me of and that I'll repeat for the benefit of those that may read this thread in the future: This is NOT the optimal setup for this saw. If you intend to use the saw at the bar's full capacity and your saw's health is a concern stick with .325 chain and go easy with any bar over 18". Thanks very much to everyone who contributed. Unless I've missed something I think I'm going to give this a try. Will add an update in the future.

Will that interfere with the oiler?

Oops, should have read the whole thread first. Carry on, nothing to learn here!

 

[KenJax Tree]

I'm not sure if you meant you respect it but will do otherwise, or you respect it and will follow the suggestion. My advice is to do as ST suggested and run .325 on the 445. It really doesn't have the power to pull 3/8" chain. You shouldn't need more than a couple of loops which really doesn't present much of a management issue. This is even more true if you plan to run a longer bar (20") on the 445. I'm 6'4" and I wouldn't even begin to consider a 3/8" 20" bar set-up on that saw. Even a saw like the 346 which has .9hp more is better suited to a .325 chain.

My brother runs his muff modded 346 with a 3/8 chain 20" bar and it does fine, he won't win a cookie cutting contest but it pulls it ok for what little he does with it.

 

[ozcutter]

Getting There




The 108215X sprocket (small spline) and 18720 (3/8 x 7) rim arrived. The good news: This combination almost gets me where I want to be. 3/8 x .050 x 72DL with a 20" narrow tail bar. The bad news: As dsell warned, it seems another oil pump gear is needed. The teeth on the spline are a too small for the oil pump pinion gear as we suspected. It works and the saw oils fine but I worry that since there is so much play in the fit that reliability may be a problem. Have the 503892103 gear ordered. If that fits the saw and fits the spline we're in business!

View attachment 239023

Did this end up working? I'm in a similar situation