Chainsaw Repair

Husqvarna - Stihl - Poulan - Jonsered - Dolmar chainsaws and more => Husqvarna => Topic started by: weimedog on September 25, 2014, 06:27:42 am

Title: Husqvarna 345/350-346 Hybrid
Post by: weimedog on September 25, 2014, 06:27:42 am
Built a 345-346 (42cc version) hybrid this week. Learned a couple of things and have a question. Learned:

1) Walbro carb from that 345 doesn't work well, especially idle & just off idle with the 42cc 346... A Zama fixed the issue
  1a) Looks like the Zama has a "hole" in the throttle plate in addition to the "notch" on the edge...wonder if drilling a hole in the Walbro's  throttle plate makes it useful?
2) Had to take around .050 off the cylinder screws.
3) Had to die grind a bit off the clutch side of the transfer port external casting to have that cylinder not interfere with the plastic case....
4) Learned it's a great running combination with no base gasket, a muffler mod and a bit more intake duration!!

Question:
The sawwas an older variant with the "course" thread mounting hardware for the cylinder and bearing cap. I put it together with 1194 AND generous amounts of 1194 on the threads of the mounting screws both top and bottom (cylinder to bearing cap & case to bearing cap) Is that going to stay together??? Or should I break that saw build down and either heli-coil to fine threads or put an aftermarket (Huztl) fine thread bearing cap in there??? Been bothering me... :-\
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Bluegill on September 25, 2014, 11:26:30 am
The coarse thread screws work fine as long as the hole has the same threads.
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Cut4fun . on September 25, 2014, 11:48:53 am
You talking OE 42mm bore 45cc 346 top end here?
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: weimedog on September 25, 2014, 08:08:25 pm
You talking OE 42mm bore 45cc 346 top end here?

Put a 42mm top end on. Also ran it back to back with the same B&C as my "Fugly" 350's. In the smaller wood the 346 seems to be better. But when I put the B&C that I had on the "Fugly one" 350 and tested back to back in a 16-18 inch hard male the modded 350 was a lot stronger. Didn't expect that.
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Bluegill on September 26, 2014, 10:16:52 am
My old 45cc OE has smoked a few ported 350s'. You either have a very strong 350, and/or something is not right with this one.
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: weimedog on September 26, 2014, 05:07:20 pm
My old 45cc OE has smoked a few ported 350s'. You either have a very strong 350, and/or something is not right with this one.

Probably a little of both. Have both tests on video... want to tweak that 346 a bit more.
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: 1manband on September 26, 2014, 08:44:58 pm
your results o'drilling or notching the throttle butterfly may vary from mine....anyhow, what i found..
-some benefit can be had, but the idle rpm has to be kept in check.
-where the hole is located plays quite a role.

have to believe that most of these carbys are pretty linear already.  messing with holes can turn the carb tuning upside down.  will take hours just to balance the low/high jets, from my experience.  imo, most of this drilling is unnecessary, for the small gain to be had.  not saying that the gain is not there, just not worth the time for most.

when the hole produces a noticeable gain, idle goes away.  don't know what your goals are, but mine were to make it more adjustable.

the air bleed, first hole has a large influence on the transition to the HS jet.  imo, is just as important.  when LS trans jets are drilled bigger....., with the bleed drilled at the same time, hope you have some hours to kill for tuning.

if the needles are see sawed....i cannot understand how it can it be better???

good luck in whatever you decide to do.

-joe
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: weimedog on September 27, 2014, 09:49:25 am
I ran a couple of tanks through it... and as Bob always points out, after breaking in & getting better ring seal is a better reference point. It's close to the modified 350. Within a second on the big wood. But it's definitely better in the small stuff. More rpm's more chain speed and as long as I don't push at it too hard and let the saw work as it chooses too it more than a little faster the modded 350. SO? Bottom line? The modded 350 has more grunt. The 346 has more speed, and the only way I know to quantify that is with the two separate test conditions.
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Cut4fun . on September 27, 2014, 09:53:45 am
When I ran stock OE 45cc against NE 50cc the OE had noticeable less torque.   

Now ported 45cc I had 2 by Dan Henry dozerdan. His 45cc port work out cut almost all the 50cc ported saws I ran against. I had a 50cc ported Dan Henry saw on hand and there was only 1 other 50cc 346 that ran with it at GTG's.   This was with 3/8 chain. The 45cc stock to me is a .325 chain saw.  Ported 45cc by dozerdan was a 3/8 saw all day.

 
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Termitebuffet on September 27, 2014, 08:30:29 pm
Weime,  I helicoiled them on mine it just seemed like the right thing to do

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Title: Re: Husqvarna 345/350-346 Hybrid
Post by: weimedog on September 27, 2014, 08:33:54 pm
Thanks! I feel more sane now because that feels like the right thing to do... All future "coarse" threaded bearing caps that go thru this shop are going to get the "flat plate" treatment and be heli-coiled to fine threads. Then I'll be able to release from that OCD feeling that they aren't right.... ??? ::)
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Cut4fun . on September 27, 2014, 10:10:47 pm
Weime,  I helicoiled them on mine it just seemed like the right thing to do

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Hey Thanks for sharing info with us.   More brain power we have the more ideas on fixes we can get.  8)

So did the TT work good on your end?
Title: Re: Husqvarna 345/350-346 Hybrid
Post by: Termitebuffet on September 28, 2014, 03:22:11 am
Weime,  I helicoiled them on mine it just seemed like the right thing to do

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Hey Thanks for sharing info with us.   More brain power we have the more ideas on fixes we can get.  8)

So did the TT work good on your end?
Yes sir ,working excellent thanks , I'll help all i can

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