Jonsered Chainsaws

[numnutz6383]

Just got picked up this little guy, 451EV, with the original manual for $50, fully functional and "recently rebuilt" per the seller/original owner Starts right up. Gonna clean it today.

Has anyone got into modding these little guys?


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Can anyone tell me some details about the heated handles on the 451EV? I'm trying to figure out if mine works. How long does it take to warm up? Is this just a gimmick or does it actually provide a good amount of heat? Any source for servicing or repairing it?

 

[Cantdog]

Can anyone tell me some details about the heated handles on the 451EV? I'm trying to figure out if mine works. How long does it take to warm up? Is this just a gimmick or does it actually provide a good amount of heat? Any source for servicing or repairing it?

No gimick....they work great. If there is a problem it will nearly always be the switch has failed but check the entire wiring for missing insulation, shorts, opens etc. These switches are very, very hard to find but since it is either on or off you can substitute a switch of similar size. It should show you heat fairly quickly (2-3 minutes) but bear in mind the system is not regulated so it will produce more heat the faster/longer the saw is operated and less heat the more time spent at idle.

 

[numnutz6383]

No gimick....they work great. If there is a problem it will nearly always be the switch has failed but check the entire wiring for missing insulation, shorts, opens etc. These switches are very, very hard to find but since it is either on or off you can substitute a switch of similar size. It should show you heat fairly quickly (2-3 minutes) but bear in mind the system is not regulated so it will produce more heat the faster/longer the saw is operated and less heat the more time spent at idle.

I see a bunch of parts on eBay for it, but as you implied, no switch. Is there a wiring diagram available somewhere?

 

[Cantdog]

I see a bunch of parts on eBay for it, but as you implied, no switch. Is there a wiring diagram available somewhere?

451 is a hard one.......many changes through out the run.....if I recall there are three totally different ign systems applied at different periods. So if you are looking for parts make certain the ones for sale are indentical to your saw.
Taplinhill has more info on these than me I think concerning what fits what period saws.

They are a dandy saw....pro limbing saw all the way!!!

 

[mogulmasher]

Cool, good info. I have a 451ev that I gotta get going as well. And of course it's missing heated handle switch.

 

[Real1shepherd]

70E
52
52E
2095
801
66

2094/2095 D'oh.

I always forget the 801 which has the 90 top cover/air filter and the same internally to the 80.
70e one of the most iconic pro J'reds.
Heard about the 52....never run one

 

[mogulmasher]

So anyone know how the tank vent on a 52 works? I just put a new carb kit in this 52 and it still runs terrible. Idle is racing and won't take to any carb adjustments. When you shut it off I hear hissing from hose on top of tank. Is the candy cane shaped hose just suppose to hang in space? Looks like it was once attached to something. What's in the little white square this hose is attached to?

 

[Bob Hedgecutter]

So anyone know how the tank vent on a 52 works? I just put a new carb kit in this 52 and it still runs terrible. Idle is racing and won't take to any carb adjustments. When you shut it off I hear hissing from hose on top of tank. Is the candy cane shaped hose just suppose to hang in space? Looks like it was once attached to something. What's in the little white square this hose is attached to? View attachment 1031813

Sounds a bit like you are chasing a massive air leak with a carb kit.
Pressure and vacuum testing time Id say.

 

[Cantdog]

So anyone know how the tank vent on a 52 works? I just put a new carb kit in this 52 and it still runs terrible. Idle is racing and won't take to any carb adjustments. When you shut it off I hear hissing from hose on top of tank. Is the candy cane shaped hose just suppose to hang in space? Looks like it was once attached to something. What's in the little white square this hose is attached to? View attachment 1031813

so.......the "Candy Cane" hose can be just like it is, except should go over the choke shaft not the choke linkage, or can be longer and travel down under the carb and across to the clutch side to exit into the clutch area. Should have a brass sintered filter in the end. The hose is attached to the tank vent in the white plastic block. If you think it is not functioning properly unscrew it from the block and shake....it has a ball inside and should rattle when shook.
I must ask the question....did you use the gasket that came with your carb kit to join the carb to the intake manifold/isolation block? If you did then your running/tuning issues are right there as that gasket is not large enough to seal the impulse corridor in the manifold. The inside throttle hole, impulse hole and bolt holes in those gaskets are correct but there is not enough outside surface area to make the seal. You can use that gasket as a template for the inside hole, impulse hole and bolt holes and make a new gasket with a larger outside area or find the carb gasket for a Husky 61, 266, 268 or 272 as they will work fine in this application.

 

[mogulmasher]

Thanks Cantdog. Yeah I took fitting off and spring loaded check ball moves freely. Makes sense it is suppose to have sintered brass plug at end. My 70e's use that and route it to behind clutch as you said.

Also didn't think about carb gasket. I've read about that issue but didn't remember it applying to these saws. Guess that is also the reason it's not starting unless I give it a shot of mix down carb.

 

[mogulmasher]

If anyone is curious this is the problem Cantdog mentioned. The pick is pointing at small area new gasket doesn't cover.

 

[Real1shepherd]

so.......the "Candy Cane" hose can be just like it is, except should go over the choke shaft not the choke linkage, or can be longer and travel down under the carb and across to the clutch side to exit into the clutch area. Should have a brass sintered filter in the end. The hose is attached to the tank vent in the white plastic block. If you think it is not functioning properly unscrew it from the block and shake....it has a ball inside and should rattle when shook.
I must ask the question....did you use the gasket that came with your carb kit to join the carb to the intake manifold/isolation block? If you did then your running/tuning issues are right there as that gasket is not large enough to seal the impulse corridor in the manifold. The inside throttle hole, impulse hole and bolt holes in those gaskets are correct but there is not enough outside surface area to make the seal. You can use that gasket as a template for the inside hole, impulse hole and bolt holes and make a new gasket with a larger outside area or find the carb gasket for a Husky 61, 266, 268 or 272 as they will work fine in this application.

Absolutely spot on in all respects, Robin. I'll bet ya anything that diamond shape carb-to-manifold gasket was used and the impulse channel isn't covered completely. You need that Husky gasket....I've posted the part number before, or you can make one easily enough.

The vents are pretty durable, but that check ball inside needs to rattle or off to the USC or whatever.....or sub in another vent unit. On the 801/80/90 they run that clutch vent tubing all the way over to the clutch side and through a little hole in the case with a sintered bronze filter in the end like Robin says. And attached to one of the top carb screws is a little ridged wire that holds the tubing. I think the 52 does all that slightly different with the candy cane affair.

The Swedes were notorious for 'over thinking' the venting on chainsaws.

Kevin

 

[Real1shepherd]

If anyone is curious this is the problem Cantdog mentioned. The pick is pointing at small area new gasket doesn't cover.View attachment 1031879

It took my brain awhile to figure out your pic...that the two gaskets were sitting on top of a vice....lol. Yes, if you lay that diamond shape gasket over the intake manifold, you'll see part of the impulse channel showing. It all needs to be covered. That was my very first post here in 2009 and Robin answered it!

Even in the Tilly full kits you get that carb gasket now. I don't know why....my old guess was it's for an old MAC or something else more popular. If you wanna buy the Husky gasket, I'll find one in the garage and part #. They're still available.

The Chinese(of course), are making those sintered bronze filters and sell them on eBay by size.

Kevin

 

[mogulmasher]

Got it back together and saw fired right off. Still needs tuning though.

Are the initial carb settings for a 52 about 1 turn out like everything else out there?

 

[Cantdog]

Got it back together and saw fired right off. Still needs tuning though.

Are the initial carb settings for a 52 about 1 turn out like everything else out there?

Yep that's where I start......

 

[mogulmasher]

Cool, did a quick tune to get it close. Seems to be running pretty well now. I just glued a small tear in air filter. Once that's dry I'll put it in some wood and dial it in. Seems to have some snappy throttle response!

 

[Cantdog]

Thanks Cantdog. Yeah I took fitting off and spring loaded check ball moves freely. Makes sense it is suppose to have sintered brass plug at end. My 70e's use that and route it to behind clutch as you said.

Also didn't think about carb gasket. I've read about that issue but didn't remember it applying to these saws. Guess that is also the reason it's not starting unless I give it a shot of mix down carb.

Yeah this gasket issue applies to all the old, true Jonsereds from the 49Sp clear up to the 90...all of 'em.....

 

[mogulmasher]

Well later today I'm throwing kits in a 621 and 451ev so I'll be sure to reuse old carb gaskets.

 

[Real1shepherd]

With the Tilly's and assuming you have no air leaks, 1 1/2-1 1/4 out on LOW and 1 1/4-3/4 out on HIGH.

I always wind up about 1 1/4 out on LOW and 3/4 out on HIGH....but that's pro lean and bar should always be in the cut. Most people should probably be a little fatter on these old saws and be 1 turn out on HIGH for performance.

I wouldn't reuse old carb gaskets. The last thing you want is the possibility of an air leak(however small) to run lean in these old saws and score your C&P.

Kevin

 

[Real1shepherd]

Those switches for the heated handles are VERY hard to find. Better to figure in another replacement switch. The OE switches weren't the best either....if you had a LOW and a HIGH setting and ran on HIGH a lot, you'd probably melt the switch.

Kevin