Jonsered Chainsaws

[Real1shepherd]

A very old silver top.....did you check with Scott? It's possible he picked up a few of those......

Kevin

 

[Cantdog]

A very old silver top.....did you check with Scott? It's possible he picked up a few of those......

Kevin

Yep and Nope........I checked all the usual culprits.....

 

[Cantdog]

Yep and Nope........I checked all the usual culprits.....

Oh you mean bulletproof........nope didn't try him......yet

 

[numnutz6383]

I put the carb of my 451 together today, but I'm having trouble with it holding a pressure. I changed all the gaskets, membranes, lever and needle with an OEM rebuild kit. I thought maybe it's because the gaskets were dry. Soaked them in 2 cycle mix. Still failed. So I put the old needle back in, wouldn't hold either.

When I pressure test in a jar of 2 cycle I get bubbles out of the venturi, didn't notice any from around the gaskets, so methinks it's the needle seat.

I watched Tinman's and Donny Walker's videos on Tilly carbs. Donny indicated using some penetrating oil to soften the needle to form around the seat sometimes helps, that's the last thing I haven't tried.

Does anyone have any other ideas before I go buying a replacement?

 

[Real1shepherd]

Oh you mean bulletproof........nope didn't try him......yet

Yeah, that Scott. Not the chainsawr Scott.... sorry for the confusion.

Kevin

 

[Real1shepherd]

I put the carb of my 451 together today, but I'm having trouble with it holding a pressure. I changed all the gaskets, membranes, lever and needle with an OEM rebuild kit. I thought maybe it's because the gaskets were dry. Soaked them in 2 cycle mix. Still failed. So I put the old needle back in, wouldn't hold either.

When I pressure test in a jar of 2 cycle I get bubbles out of the venturi, didn't notice any from around the gaskets, so methinks it's the needle seat.

I watched Tinman's and Donny Walker's videos on Tilly carbs. Donny indicated using some penetrating oil to soften the needle to form around the seat sometimes helps, that's the last thing I haven't tried.

Does anyone have any other ideas before I go buying a replacement?

I've never had an issue with a Tilly and a new needle seating. Back in the day they weren't even rubber-tipped but all brass....never had trouble with those either.

I know it's an added expense, but if you do more than one carb a yr, invest at least $50 in a HF USC. Or just nut up and buy a used commercial unit(I should follow my own advice!). Or....spend some on a Chinese-made unit with all the bells & whistles(mostly a longer cycle and a good heater).

Saving that, buy the gallon cans of carb cleaner like NAPA brand with the dip tray and use that. It's the only way you'll know you got the carb spotless inside.

I've never been let down using those methods and I clean and rebuild carbs up to racecar Webers.

Sounds like you still have some gunk or a bad surface where the needle seats. Get a loupe or some kinda magnifier and examine that seat!

Kevin

 

[Zero_sum]

So.........does anyone in here have or know anyone that has any 751 parts??

I do not unfortunately. That's a tough one. I did just rescue another 601 from the dump a couple of weeks ago complete with the original recoil handle.

 

[numnutz6383]

I've never had an issue with a Tilly and a new needle seating. Back in the day they weren't even rubber-tipped but all brass....never had trouble with those either.

I know it's an added expense, but if you do more than one carb a yr, invest at least $50 in a HF USC. Or just nut up and buy a used commercial unit(I should follow my own advice!). Or....spend some on a Chinese-made unit with all the bells & whistles(mostly a longer cycle and a good heater).

Saving that, buy the gallon cans of carb cleaner like NAPA brand with the dip tray and use that. It's the only way you'll know you got the carb spotless inside.

I've never been let down using those methods and I clean and rebuild carbs up to racecar Webers.

Sounds like you still have some gunk or a bad surface where the needle seats. Get a loupe or some kinda magnifier and examine that seat!

Kevin

If it is a bad surface and not just removable gunk, what's the remedy, if any?

 

[numnutz6383]

I've never had an issue with a Tilly and a new needle seating. Back in the day they weren't even rubber-tipped but all brass....never had trouble with those either.

I know it's an added expense, but if you do more than one carb a yr, invest at least $50 in a HF USC. Or just nut up and buy a used commercial unit(I should follow my own advice!). Or....spend some on a Chinese-made unit with all the bells & whistles(mostly a longer cycle and a good heater).

Saving that, buy the gallon cans of carb cleaner like NAPA brand with the dip tray and use that. It's the only way you'll know you got the carb spotless inside.

I've never been let down using those methods and I clean and rebuild carbs up to racecar Webers.

Sounds like you still have some gunk or a bad surface where the needle seats. Get a loupe or some kinda magnifier and examine that seat!

Kevin

Well, I invested in a $125 USC (6 liter) back in November and I'm fairly certain I cleaned this carb in it then. I'll peak at needle seat with my loupe and I'll take it apart again and give it a clean in carb cleaner in the USC.

 

[Real1shepherd]

Well, I invested in a $125 USC (6 liter) back in November and I'm fairly certain I cleaned this carb in it then. I'll peak at needle seat with my loupe and I'll take it apart again and give it a clean in carb cleaner in the USC.

There's a chance you might see the issue right off with a good loupe.

Not anything common to Tilly carbs though..........

Kevin

 

[Real1shepherd]

If it is a bad surface and not just removable gunk, what's the remedy, if any?

I'm sure there's a tool and some sort of polisher at the last.....but not practical for the average DIYer. If it had been a problem in the many Tilly's I've done, I would have looked into a tool.

Kevin

 

[Cantdog]

If you still have the old metering needle you might find a couple inches of fuel line the right diameter to fit snugly over the outer end of it and with some metal polish lilke Flitz or similar on the rubber tip use the old needle to lap the seat in the carb body like you would an engine valve.......just a thought.....

I am not sure what height the metering lever it supposed to be set at on those carbs but will look on my Tilotson carb tool when I get to the shop later today.

 

[Cantdog]

I do not unfortunately. That's a tough one. I did just rescue another 601 from the dump a couple of weeks ago complete with the original recoil handle.

Yep 75 and 751 are pretty darn rare to find. I see a fair amount of 601s and parts on ebay. I love running my 601......it's so smooth you kinda don't get that it has no AV .

I'v been looking for a 751 for years........the only other one I've actually seen was PB's and I tried to get that from him when he left Maine as he was thinning out the herd a bit for the move......but he wouldn't part with it......

 

[numnutz6383]

If you still have the old metering needle you might find a couple inches of fuel line the right diameter to fit snugly over the outer end of it and with some metal polish lilke Flitz or similar on the rubber tip use the old needle to lap the seat in the carb body like you would an engine valve.......just a thought.....

I am not sure what height the metering lever it supposed to be set at on those carbs but will look on my Tilotson carb tool when I get to the shop later today.

I have Flitz but does my metering module body is made out of plastic, should still give that a try?

Per my Tillotson service manual, "the top of the inlet control lever should be flush to the diaphragm chamber floor".

 

[Cantdog]

Ahhh that's right.....I haven't had any problems with those HK carbs with the plastic lowers......I know from reading on here years ago that alot of folks did have problems with those. You use to be able to buy a new plastic part but not sure if you still can....I remember that the biggest problem is the plastic would warp over time.

So no.... probaly Flitz wouldn't touch plastic.

 

[Real1shepherd]

Not familiar with plastic lowers....bad juju.

I originally thought you could see the flaw with a loupe.....but in warped plastic....not so sure.

You'd have nothing to lose if you used Robin's method and water base grinding compound even with the plastic lowers. Warped though.....most likely a goner.

All the 'modern' HK/HS Tilly's I know of always have the lever flush.

Kevin

 

[psc1947]

Jonsered! Saw that word several times and finally had to look it up. I had been reading it as a verb and wondered how you "Jonser" a saw

 

[Real1shepherd]

Jonsered! Saw that word several times and finally had to look it up. I had been reading it as a verb and wondered how you "Jonser" a saw

You'll also see J'red(s), Johnny, and Red saw. Originally it was Jonsereds with the 910 series being the last truly authentic original company saw. Electrolux Group AB bought Jonsreds, Partner, and eventually Husqvarna. Somewhere around the time of the 910, they dropped the 's'. There's no definitive date on that.....some go by the advertising literature and others go by what the dealers said at the time like Tilton and Scotsco.

Kevin

 

[psc1947]

Thanks

 

[Maintenance supervisor]

Had it running pretty good, but the o-ring crapped out and was causing weird tuning.