Husky 450 - limited coil?

[Husq445]

Well had to know so I went out and checked

Terry you might be right.

I could have sworn that this 445 was running more rpm than that but I also didnt have a lot of time to warm it up, seeing as I ran it quick in the garage.
Might have been the 290 that I was thinking of having some issues with that running well over 14000.

It was running right at 13000

The numbers on the coil are,

504 57 14-01
NBU-16B 1258

Rick

 

[Terry Syd]

Trouble shooting

Yeah, trouble shooting with a limited coil is a pain. It's kinda funny though when I think of myself listening to the ignition miss during a cut - stop and change plug - listening to the plug miss again while cutting - change again to another plug - still missing - then finally setting the mixture a bit richer to pull down the revs and remove the ignition miss -and never figuring out it had a limited coil. I think that qualifies for a 'duh'.

With the present porting, a lmited coil that had a 13,600 limit would probably give me enough breathing room for easier tuning. It looks like I'm going to have to run this saw right on the edge of the limiter.

 

[AKDriveSprocket]

Same thing with my new Husky 365 special. It's limited to 13,600.

I think your 365 is maxed out at 12,600 unless it is modified. I do think the coil is limited to 13,600 but the max is 12600 on the 365. Of coarse I have been wrong before. Sorry to high jack you thread but, hate to see him burn up his saws.

 

[J.Walker]

I think your 365 is maxed out at 12,600 unless it is modified. I do think the coil is limited to 13,600 but the max is 12600 on the 365. Of coarse I have been wrong before. Sorry to high jack you thread but, hate to see him burn up his saws.

I'm not quite sure? Have not read the manual yet. The saw is going to be Modified soon! It's going to be my 4 cube racesaw.

 

[Terry Syd]

Walbro list of modules

I contacted Walbro and they sent me a copy of their list of ignition modules. It appears that a MB-8A or MB-9A could be a non-limiting coil swap for the present MBU-16B. I'll have to do some more research - comments are welcomed.

 

[Terry Syd]

Mb-48

It looks like the MB-8A was superceded by the MB-18, which was then superceded by the MB-48 with an instantaneous kill function (THAT sounds ominous).

The list dealer list price for the MB-48-1 is $28.41 and has a Husky part number of 5374186-01. Now to try and find out what that coil came off of.

 

[Trigger Man]

I think your 365 is maxed out at 12,600 unless it is modified. I do think the coil is limited to 13,600 but the max is 12600 on the 365. Of coarse I have been wrong before. Sorry to high jack you thread but, hate to see him burn up his saws.

The 365 should be max at 12,500 rpm, at least thats what the sevice manual says. Like everyone else suggests though you should run the saw in the wood to verify its running proper, four stroking out of the cut.

 

[Terry Syd]

4-stroking

The problem with these limited coils is that the engine will sound very similar to 4-stroking out of the cut. It was only under partial load that I could hear the distinct individual ignition misses.

I'm new to chainsaws and up until now I have been interpreting the limited coil cut-off as 4-stroking. Thankfully, I have been tuning by the plug color so I haven't stuck the engine.

It looks like the MB-48 coil may be on the Husky 235. Does anybody know what the 235 manual says in regards to setting the carb?

 

[bitzer]

I recieved an email about the coil on my Husky 455. It is made by SEM AB and they said that only their blue coils are limited. The black are not. Mine is black. Good to know info for Walboro and SEM coils!

 

[Terry Syd]

Walbro coils

Yeah, and unfortunately I have the Walbro coil, the're all black. The list from Walbro I posted above has various coils for different applications and the advance, cut-off, current output and other features vary with each coil.

I still haven't found out anything about the MB-48 coil, other than it isn't that expensive. The fact it is on a smaller 32cc engine may mean that the flywheel is smaller and thus the coil armatures are shaped for the smaller flywheel. That probably wouldn't be a problem, I could just shape them a bit and then lap them against the flywheel using some sandpaper. However, it is the internal eletronics I'm more concerned with.

Sometimes I yearn for the days of simplicity; coil, points, condensor. I once had a mate's new/used CZ that wouldn't start and he was in a tizzy because he had arranged for a photo-shoot at a MX course the next day for a magazine article. I went over to give him and hand and found there was no condensor/capacitor on the bike. I jumped the fence to the auto repair place across the street and pulled a capacitor off a VW to use on the bike. We got it running and the photo-shoot/race went ahead as planned. You could fix those bikes with a screw driver and spanner wrench.

Bloody 'black boxes'.