Jonsered Chainsaws

[Real1shepherd]

Thanks Kevin.

Looks like the old gasket was paper, not much of it left at this point. I'll see if I can get a piece to measure thickness, make my way over to NAPA and get an oil resistant material and cut-to-fit.

I saw a few posts by yourself and @Cantdog regarding impulse corridors and gaskets on Jonsered saws. Could you explain that bit to me a little?

View attachment 1035819

If you don't have an impulse tube and a rubber carb boot.....then the manifold block itself(the part the carb attaches to) has an impulse channel in the block itself. Some are very straightforward looking and some are like wiggly snake canals. What's important is that the gasket completely covers the impulse channel.

If you have the impulse tube and a rubber carb boot, you don't worry about any of this.......except for the integrity of the impulse tube and the rubber boot. From your partial IPL, it looks like the impulse channel on your manifold block is at the top and center.

They went to this design to keep more heat away from the carb/fuel lines......the boot makes the carb stand off a bit from the cylinder.

Kevin

 

[numnutz6383]

If you don't have an impulse tube and a rubber carb boot.....then the manifold block itself(the part the carb attaches to) has an impulse channel in the block itself. Some are very straightforward looking and some are like wiggly snake canals. What's important is that the gasket completely covers the impulse channel.

If you have the impulse tube and a rubber carb boot, you don't worry about any of this.......except for the integrity of the impulse tube and the rubber boot. From your partial IPL, it looks like the impulse channel on your manifold block is at the top and center.

They went to this design to keep more heat away from the carb/fuel lines......the boot makes the carb stand off a bit from the cylinder.

Kevin

I think I was editing my post as you were replying. EDIT: I have to read more carefully before replying.

Do I have this right? So if impulse is top, what's the little hole at the bottom of the manifold that actually has a connection into the cylinder (seen in 2nd picture).

 

[Real1shepherd]

I think I was editing my post as you were replying. EDIT: I have to read more carefully before replying

It's all good.

Whenever I post something, I will probably tweak it for at least 10 minutes afterward. Best to give me that space so I can get it all down.....what's in my head besides rocks.

Look at the manifold block itself carefully....make sure there are no passageways connected to that top channel. The hole on the bottom has to be the primary impulse, looking at your new cylinder. But, you could have a channel inside the manifold block that routes its way clear back to the top for the carb's sake/design.....that's why I say to look at that manifold block carefully. If you can't find any way they deliver a vacuum to that top channel, I'm betting it's dead space. Also, if my eyes are working, it looks like the old gasket can be flipped either way and the top of it(because of the impulse hole) didn't completely cover that manifold channel. More reason to think that upper channel has no use.

I'm never in the habit of taking those manifold blocks off unless I absolutely have to.....as you have to for a cylinder refit. There are some notorious Husky models that develop manifold cracks and leaks I'm told.

Show a nice pic of the face of your carb.....the part that goes against the manifold block.

Kevin

 

[Cantdog]

Thanks Kevin.

Looks like the old gasket was paper, not much of it left at this point. I'll see if I can get a piece to measure thickness, make my way over to NAPA and get an oil resistant material and cut-to-fit.

I saw a few posts by yourself and @Cantdog regarding impulse corridors and gaskets on Jonsered saws. Let me see if I'm understanding this, if there is an impulse channel between the carb, manifold and cylinder, then the channel should be left completely unobstructed by the gasket. In the second and third pictures you can see the gasket that came off the manifold/carburator partially obstructs this hole, so in my rebuild I should assure this passage is clear, yes?

View attachment 1035819

View attachment 1035887
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Yeah....the carb to manifold gasket (middle pic) is fine and I would just reuse it. The impulse corridor is not as much of an issue on the 451 as all the holes line right up or are wide enough to allow for any alignment issues....unlike the larger Jonsereds saws on which the gasket becomes the impulse corridor.
Those OEM cyl to manifold gaskets really get baked on......never seen one come off in one piece. When you assemble all this stuff don't go crazy with sealant. I rarely use any...good gaskets don't need any. If your cyl base gasket is thin paper like most I fold it into a moist paper towel for a few minutes before trying to fit it. Makes it very plyable and most old paper gaskets by now have shrunk up pretty bad so this helps with this too.

 

[Real1shepherd]

Yeah....the carb to manifold gasket (middle pic) is fine and I would just reuse it. The impulse corridor is not as much of an issue on the 451 as all the holes line right up or are wide enough to allow for any alignment issues....unlike the larger Jonsereds saws on which the gasket becomes the impulse corridor.
Those OEM cyl to manifold gaskets really get baked on......never seen one come off in one piece. When you assemble all this stuff don't go crazy with sealant. I rarely use any...good gaskets don't need any. If your cyl base gasket is thin paper like most I fold it into a moist paper towel for a few minutes before trying to fit it. Makes it very plyable and most old paper gaskets by now have shrunk up pretty bad so this helps with this too.

I second that about sealant. Gasoline and gas vapor is really hard on sealants all the way up to large motors. Lots of folks try to use sealants that break down over time from the gas. MUCH better not to use sealant in this application.

That cylinder-to-manifold gasket IS next to impossible to get off......I never mess with those if I can help it. Same issue on the older big cc Huskies. Gently clean up those ridges on the manifold....they're there to help make the seal.

And ditto on the base gasket. I too wet them to make them more pliable!


Kevin

 

[Cantdog]

I second that about sealant. Gasoline and gas vapor is really hard on sealants all the way up to large motors. Lots of folks try to use sealants that break down over time from the gas. MUCH better not to use sealant in this application.

That cylinder-to-manifold gasket IS next to impossible to get off......I never mess with those if I can help it. Same issue on the older big cc Huskies. Gently clean up those ridges on the manifold....they're there to help make the seal.

And ditto on the base gasket. I too wet them to make them more pliable!


Kevin

LOL!! Yep learned that on my first road motorcycle......a 194 2HD Flathead chopper....lot of paper gaskets and by the time I got them (early 70s) they were very warped/dried out/deformed.........and oil pump gaskets were thicknes specific as they set up oil pump clearences ........two pumps on those......a pressure pump and then a larger scavenger/return pump........strange **** you pick up along the way!!! LOL!!!

 

[ErnieG]

My 2171 project came with the plug wire missing from the coil .
Could this be repaired or is the coil useless ?
Thanks
Ernie

 

[Woodslasher]

My 2171 project came with the plug wire missing from the coil .
Could this be repaired or is the coil useless ?
Thanks
Ernie

You can screw in a new wire, heck, if you go into a decent Husky shop and say you need a new plug wire setup they should have everything on hand for $12-15.

 

[numnutz6383]

It's all good.

Whenever I post something, I will probably tweak it for at least 10 minutes afterward. Best to give me that space so I can get it all down.....what's in my head besides rocks.

Look at the manifold block itself carefully....make sure there are no passageways connected to that top channel. The hole on the bottom has to be the primary impulse, looking at your new cylinder. But, you could have a channel inside the manifold block that routes its way clear back to the top for the carb's sake/design.....that's why I say to look at that manifold block carefully. If you can't find any way they deliver a vacuum to that top channel, I'm betting it's dead space. Also, if my eyes are working, it looks like the old gasket can be flipped either way and the top of it(because of the impulse hole) didn't completely cover that manifold channel. More reason to think that upper channel has no use.

I'm never in the habit of taking those manifold blocks off unless I absolutely have to.....as you have to for a cylinder refit. There are some notorious Husky models that develop manifold cracks and leaks I'm told.

Show a nice pic of the face of your carb.....the part that goes against the manifold block.

Kevin

On close inspection I'm certain there is no connection between the top channel and the impulse hole at the bottom, it's just dead space. And you are correct, flipping the gasket has the same effect. Which brings me to the requested picture.

I got a felpro variety kit from Napa, I'll cut a new gasket for the cylinder/manifold and reuse the carb/manifold gasket, once I rebuild the carb.

You guys weren't kidding when you said the cylinder/manifold gasket is impossible to completely remove. I tried using a plastic razor knife to get it off and nothing. What's the best way to do this? Does it even need to be completely clean? As for sealant, I saw yamabond 4 being highly recommended on here, but if you guys say not to use it, I won't and I'll just go paper only.

 

[numnutz6383]

Yes, be gentle because the insulation on these old saws degrades. I use a marine-grade brush on insulation if I don't want to take the ends off. If the ends come off, put back heat shrink. Lots of modules have been brought back to 'life' simply by re-insulating the wires.

Kevin

I searched for a "marine-grade" brush and didn't come up with anything, or rather anything properly sized for the task.

I looked at my coil and module yesterday and the insulation definitely is breaking down right at the insertion into both. After I clean it GENTLY with isopropyl, I thought about using heat shrink over them but I don't think that will do the trick, given where the wear is.

Should I secure these with some kind of epoxy?

 

[Real1shepherd]

On close inspection I'm certain there is no connection between the top channel and the impulse hole at the bottom, it's just dead space. And you are correct, flipping the gasket has the same effect. Which brings me to the requested picture.

I got a felpro variety kit from Napa, I'll cut a new gasket for the cylinder/manifold and reuse the carb/manifold gasket, once I rebuild the carb.

You guys weren't kidding when you said the cylinder/manifold gasket is impossible to completely remove. I tried using a plastic razor knife to get it off and nothing. What's the best way to do this? Does it even need to be completely clean? As for sealant, I saw yamabond 4 being highly recommended on here, but if you guys say not to use it, I won't and I'll just go paper only.

Yamabond is OK if you have to, but preferably not. NAPA and I imagine others have a spray product made to remove gaskets/residue....try that if patience and a razor don't work. Yes, everything needs to be clean to get a good seal and no air leaks. Don't start out with an air leak and a new P&C.

Your impulse is definitely on the bottom of the carb/cylinder flange. If you feel confident, I'd make both gaskets. If you're determined to use the old carb-to-manifold gasket, at least soak it in water for a while and let it dry. Sometimes that rejuvenates their depressions. Anyone making gaskets should have a set of hole punches(Habor Freight, but you have to sharpen them) and a little gasket cutter that cuts circles. The outline itself of the gasket can be cut with a razor knife etc. I actually enjoy making gaskets.....it's therapeutic. Especially paper....rubber can be tedious because it stretches sometimes while you're trying to cut it.

Here's a pic of the product I use for failing wire insulation....I think I got it on Amazon from a vendor. I would do two coats; letting it completely dry after the first. Don't goober it on; better to use thin coats. Epoxy will work if it's close to the module, but that makes it stiff and from there downstream the insulation will still try to de-laminate.

If for example, you have a bad place where a case part or whatever is pushing/rubbing against the wires.....I would use two coats of liquid insulation and then a piece of heat shrink over that. If you can't get the heat shrink over the terminal end of the wire......I'd split it longways(ID of the heat shrink the same as the wire OD), with a razor knife, and put it on with more liquid insulation. This way you're making a 'bumper' for the wear point. Close-up pics please of the damage.

This all started when Euro manufacturers began using soy wiring harnesses and soy insulation. They thought they were being eco-conscious. What it did, in reality, was make old insulation decompose.

Kevin

 

[Real1shepherd]

My 2171 project came with the plug wire missing from the coil .
Could this be repaired or is the coil useless ?
Thanks
Ernie

Not familiar with that model to work on....BUT those plug leads aren't all screwed on. I ruined a coil on an 80 by trying to unscrew the coil lead....it was molded in somehow. Not saying yours is, but you should see the little screw threads inside the coil if it does work that way.

You guys gotta post pics with questions like these...

Kevin

 

[ErnieG]

Not familiar with that model to work on....BUT those plug leads aren't all screwed on. I ruined a coil on an 80 by trying to unscrew the coil lead....it was molded in somehow. Not saying yours is, but you should see the little screw threads inside the coil if it does work that way.

You guys gotta post pics with questions like these...

Kevin

I will post some pics when I get a chance but I did find a replacement for now but I will try and repair it this one if it's possible.
Thanks
Ernie

 

[numnutz6383]

Yamabond is OK if you have to, but preferably not. NAPA and I imagine others have a spray product made to remove gaskets/residue....try that if patience and a razor don't work. Yes, everything needs to be clean to get a good seal and no air leaks. Don't start out with an air leak and a new P&C.

Your impulse is definitely on the bottom of the carb/cylinder flange. If you feel confident, I'd make both gaskets. If you're determined to use the old carb-to-manifold gasket, at least soak it in water for a while and let it dry. Sometimes that rejuvenates their depressions. Anyone making gaskets should have a set of hole punches (Harbor Freight, but you have to sharpen them) and a little gasket cutter that cuts circles. The outline itself of the gasket can be cut with a razor knife etc. I actually enjoy making gaskets.....it's therapeutic. Especially paper....rubber can be tedious because it stretches sometimes while you're trying to cut it.

Here's a pic of the product I use for failing wire insulation....I think I got it on Amazon from a vendor. I would do two coats; letting it completely dry after the first. Don't goober it on; better to use thin coats. Epoxy will work if it's close to the module, but that makes it stiff and from there downstream the insulation will still try to de-laminate.

If for example, you have a bad place where a case part or whatever is pushing/rubbing against the wires.....I would use two coats of liquid insulation and then a piece of heat shrink over that. If you can't get the heat shrink over the terminal end of the wire......I'd split it longways(ID of the heat shrink the same as the wire OD), with a razor knife, and put it on with more liquid insulation. This way you're making a 'bumper' for the wear point. Close-up pics please of the damage.

This all started when Euro manufacturers began using soy wiring harnesses and soy insulation. They thought they were being eco-conscious. What it did, in reality, was make old insulation decompose.

Kevin

Ok. No yamabond.
I got a set of hollow punches at HD the other day after figuring I may be making the gasket(s). How do you even sharpen these? I was able to order a new carb/manifold gasket, so I think I'll just use that, unless it looks radically different than the one I have. I'll get some liquid tape to try on the wires. I'll post pics of the areas of concern tomorrow.

 

[Real1shepherd]

Ok. No yamabond.
I got a set of hollow punches at HD the other day after figuring I may be making the gasket(s). How do you even sharpen these? I was able to order a new carb/manifold gasket, so I think I'll just use that, unless it looks radically different than the one I have. I'll get some liquid tape to try on the wires. I'll post pics of the areas of concern tomorrow.

Don't just get any ol' liquid tape like @HD. It's not the same.....that marine stuff is way better.

The punches in the set from HF are dull, really dull. You take a medium stone(like from a Lansky knife sharpening set, for example), hold the punch straight up ....then take your stone and sweep toward the center of the point with it....at the same angle they made when they did the tip taper. Do that all the way around until you see that the taper is evenly sharpened from the stone. I suppose you could use an emery wheel on something electric, but you only need to remove very little to get them sharp.

Other than the fact they come dull, it's a pretty good set.......

Kevin

 

[numnutz6383]

Don't just get any ol' liquid tape like @HD. It's not the same.....that marine stuff is way better.

The punches in the set from HF are dull, really dull. You take a medium stone(like from a Lansky knife sharpening set, for example), hold the punch straight up ....then take your stone and sweep toward the center of the point with it....at the same angle they made when they did the tip taper. Do that all the way around until you see that the taper is evenly sharpened from the stone. I suppose you could use an emery wheel on something electric, but you only need to remove very little to get them sharp.

Other than the fact they come dull, it's a pretty good set.......

Kevin

Just a heads up, the Shoreline Marine liquid tape you have is no longer being sold (I came across an article that it was recalled in Canada), at least I can't locate it. But apparently that was manufactured by Star Brite. In my googling I came across Gardner Bender, Star Brite and West Marine house brand as all widely available around me, and all mention marine use in some way, and a few other that are orderable but I didn't look into marine use for those.

 

[Cantdog]

This is what I use.......except mine is older and made from cast steel.......very nice for making saw gaskets...

 

[Cantdog]

A little tip on cutting gaskets. I've found there is a difinitely and order to the work. Cut all the holes first, then carefully cut out the inside with a very sharp exacto knife and finally cut the outside with scissors. If you vary from this order you will just make it harder than it needs to be.

Notice there are several test holes on the outside edge of the gasket material......this is allow me to see the "grain" of the paper and what I need to do to create a crisp, accurate hole. With this punch I find that a gentle twist back and forth at the end process severs the fibers nicely.

 

[Real1shepherd]

Those dial-a-hole punch tools do work, but I wanted more variety of holes than that offered for larger engine gaskets. Plus, the one I bought was a POS. I'm sure there are probably still good ones out there, but I bet it would exceed the price of the full HF punch set.

I agree with Robin on the sequence; I cut the small holes first, check against the gasket.....then the center hole and finally the outline of the gasket. I do the small holes first and check because if you do them at the end you have all the time into that gasket and have to pitch it if you made a mistake. Keep checking your gasket against the original as you proceed along. You can also punch your small holes 'through' the old gasket....just take care you don't damage your 'template'.....lol.

I was lucky enough to score an old Spearhead NO. 750 "Handy Gasket Cutter" made by Zimmerman Packing way back in the day. The set was new and never used, a metal box with a metal hinge....lol. . Even has a pivot piece you can drive into a wooden surface board or a Delrin board to cut your gasket on. I had to read the instruction a few times to understand all the ins & outs, but it's a pretty great tool.

Kevin

 

[Real1shepherd]

Just a heads up, the Shoreline Marine liquid tape you have is no longer being sold (I came across an article that it was recalled in Canada), at least I can't locate it. But apparently that was manufactured by Star Brite. In my googling I came across Gardner Bender, Star Brite and West Marine house brand as all widely available around me, and all mention marine use in some way, and a few other that are orderable but I didn't look into marine use for those.

I found it @Walmarthttps://www.walmart.com/ip/Shoreline-Marine-Liquid-Electrical-Tape/28429509

That might be an old link, but they say they have it. I probably bought it from Amazon, but you're correct, it's not there anymore. Walmart can be really funky to order online from because they use vendors and rarely check up on them. Unlike Amazon, if you go through a vendor and the deal sours, Walmart will tell you your beef is with the vendor. We're not talkin' a lot of money here, so I'd take the chance if you can order it through Walmart.

I was trying to get you to stay away from Star Brite(in the yellow can) and another brand I dislike called 'Brush-On' by Bluemagic. I haven't tried all of them out there, but at least four major brands. The Shoreline Marine product was a head taller than the rest.

If you went to an industrial site that catered to people manufacturing boats, I bet you'd find a good product maybe even more durable than the Shoreline product.

Kevin