Jonsered Chainsaws

[Real1shepherd]

Hey Robin, a bit more positive results today but still not running smoothly. Starting isn't a problem, usually fires on the first or second pull but keeping it running is difficult. Runs ok with the choke pulled halfway out. When I push the choke in, the engine surges for a bit then dies. When I work the throttle it slowly dies like it's starved. I've kept it running for maybe a minute if I keep the choke at halfway. If I attempt to move it either direction it dies.

Seems carb related to me. I'm going to check the metering level and the diaphragm again.

Does sound exactly like carb....the Tillotsons are a bit fussy about the metering level....that's why I cautioned about setting the lever exactly as Tillotson said to. The lever for the diaphragm needs to be exactly even with the floor of the chamber. I'm betting something isn't right inside that carb.....like Robin said, it's very easy to miss hooking that diaphragm into the lever fork. You have to leave the diaphragm in it's proper place and sort of peel up one edge and peek under there to see if it's hooked correctly. Also make sure the spring for the metering lever is centered on dimple.

Also if I remember correctly the 'sandwich' on the top is;carb/diaphragm/gasket....but on the bottom it's;carb/gasket/diaphragm.

Kevin

 

[Real1shepherd]

That's not the spark coil...it's actually a magneto/generator coil that provides the power for the spark coil which is waterproof and encased in black plastic as you imagine......the spark coil is separate and mounts under the top cover and is not timed by the flywheel but by the points. This ign system is common to the models 60, 601, 62, 621, 751, 80, 81, 801 and 90 and maybe a few others.

Great explanation!

Kevin

 

[Cantdog]

Hey Robin, a bit more positive results today but still not running smoothly. Starting isn't a problem, usually fires on the first or second pull but keeping it running is difficult. Runs ok with the choke pulled halfway out. When I push the choke in, the engine surges for a bit then dies. When I work the throttle it slowly dies like it's starved. I've kept it running for maybe a minute if I keep the choke at halfway. If I attempt to move it either direction it dies.

Seems carb related to me. I'm going to check the metering level and the diaphragm again.

Hmm.........check the lever and pin connection and be certain you have the gaskets in the correct order on both sides of the carb...on the bottom it's gasket and then the diaphragm then the cover. On top it's diaphragm first, then gasket, then cover........is the diaphragm spring in good condition and not been damaged in any way? They are very fragile and will not tolerate being stretched or kinked at all.....

Ooopps......didn't read Kevins post...Sorry didn't mean to trepeat...

 

[67L36Driver]

370 piston carnage and a 'whatszit'.

What is the round rubber thing sits under the carb.? Above the piston/crankcase in the picture. I figure to glue him back in with 3M weatherstrip adheasive.

 

[Cantdog]

370 piston carnage and a 'whatszit'.

What is the round rubber thing sits under the carb.? Above the piston/crankcase in the picture. I figure to glue him back in with 3M weatherstrip adheasive.

View attachment 337182

That is a cushion for the bottom of carb to sit on. Carb is mounted to the rubber boot on the front and that single throughbolt with rubber bushing in the back of the intake horn. The cushion holds the carb steady. Doesn't really need to be glued...sits in a hole in the case......when the carb is in place it can't go anywhere.

Piston look poor.....better make sure what the cause of that was and take proper counter measures....... that is the early two piece ign I believe is it not?

 

[67L36Driver]

Thanks bud.

Now I remember. The long bolt on the plastic elbow.

Straight gas victim.

 

[Real1shepherd]

370 piston carnage and a 'whatszit'.

What is the round rubber thing sits under the carb.? Above the piston/crankcase in the picture. I figure to glue him back in with 3M weatherstrip adheasive.

View attachment 337182

Are you going to be able to salvage the cylinder?

Thanks bud.

Now I remember. The long bolt on the plastic elbow.

Straight gas victim.

Gas with no oil?? Wow......

Kevin

 

[67L36Driver]

Havn't got back to him. Freakin' cold in the garage.

 

[Real1shepherd]

Hear that....ice storm came through here yesterday. I went with my ex and her sister to the casino last night, skating on ice. Watched the ex jackpot the same machine four times...$4,000.

A lesser man would have rolled her in the parking lot and taken the spoils...

Kevin

 

[67L36Driver]

Big winners buy dinner.

 

[Real1shepherd]

Unfortunately for me, the sister's housemate was making a nice meatloaf dinner, of which I wasn't a part. But yeah, I was pushing for the all-you-can-eat buffet at the casino.

Kevin

 

[Chris J.]

370 piston carnage and a 'whatszit'.

What is the round rubber thing sits under the carb.? Above the piston/crankcase in the picture. I figure to glue him back in with 3M weatherstrip adheasive.

View attachment 337182

670, yes?

 

[Chris J.]

The seller got his $500.00.

http://www.ebay.com/itm/vintage-cha...W643iZjK%2BHmU9%2FNxo%3D&orig_cvip=true&rt=nc


I'm not going to pretend to know what all models these are for, but I'm thinking that someone got a good deal.

http://www.ebay.com/itm/LOT-OF-MISC...W643iZjK%2BHmU9%2FNxo%3D&orig_cvip=true&rt=nc

 

[Real1shepherd]

Yes he did, unless it was shill bidding...there was just one bid. But I have no reason to think that;100% feedback over a large amount of items.

Yeah I saw the handle sale....I could use some of those myself, but the shipping is $27, so can't ignore that cost at the end of the auction. Oops, gone...sold for $10 plus shipping!

Kevin

 

[Real1shepherd]

There was this too....I started to bid, but figured I could direct that money into something else I need more.:http://www.ebay.com/itm/NOS-Jonsered-90-Chainsaw-Engine-Cylinder-54-mm

Didn't sell this time around....

Kevin

 

[Real1shepherd]

Here's a 621 silver top that's listed in many Jred model auctions, for parts;http://www.ebay.com/itm/Jonsered-621-chainsaw-parts-only-180-PSI-runs-49-70-80-90-52-rare-vintage


Kevin

 

[SawTroll]

Here's a 621 silver top that's listed in many Jred model auctions, for parts;http://www.ebay.com/itm/Jonsered-621-chainsaw-parts-only-180-PSI-runs-49-70-80-90-52-rare-vintage


Kevin

180 PSI actually is quite low on a 621, and not a good sign.

 

[Flat47]

Working on a 630 Super II and was wondering what the benefits of the dual fuel lines are? Fuel economy?

 

[Cantdog]

Working on a 630 Super II and was wondering what the benefits of the dual fuel lines are? Fuel economy?

That's the recirculating carb.......one is fuel in the other a return to the tank.....I think it's an economy and performance thing...carb gets all the fuel it needs.....always has plenty enough for quick spool up but does not allow pressure to build when spooling down..they seem to work good.

 

[Chris J.]

I don't know if this has been mentioned. It seems that seller doesn't know that it's a 90, not a 80. I'm not trying to ruin anyones sleeper, maybe if someone here really wants it they'll speak up and the rest of us can hold off.

http://www.ebay.com/itm/31088741280...69&ssPageName=STRK:MEBIDX:IT&autorefresh=true