346xp problems

[Dalynn]

Hi All I;ve got problems with two of my 346xps. One is about 3years old and about three months ago started to become difficult to start and started cutting out when idling.

Took it to local dealer who said piston and barrel needed replacing Charged me £300 for doing it.

The second one is just over a year old and within a week of the other one developed exactly the same fault. Another £300 and I had them both back in service

That was back on November.

Both have done less work than usual since then due to the bad weather.

Last week one developed exactly the same symptoms as before and today the second one siezed solid. If freed off when it cooled but is now showing the same symptoms Ie hard to start and cutting out.

We are always meticulous with oil mixes and have run them at 120ml of sthil oil per 5 litre rather than 100ml since the last problems.

Filters are cleaned daily, Plugs changed about once a month.

Is it just our bad luck or is there a problem with 346's. Should I be looking at bad techniques from the lads.

Don't want to waste another £600 at the dealers so I'm looking at swapping to MS261's

Any comments or suggestions would be welcome.

[spudulike]

It sounds like the route cause for the oiginal seizeure wasn 't found - it is possible that you have saws either set too lean or may have air leaks - all this should have been checked when the new P&C were fitted.

 

It is also possible you have other issues - old fuel mix being used? dodgy fuel? Operators that like fiddling with the carb H screw?

 

Difficult to tell but any good tech would pressure and vac check the saw after rebuild and then tach the saw to around 14100 on a 346xp and then re-tach to around 14,500 after 15 tanks has been run through it!

 

Thats what I think:thumbup:

[Goaty]

It sounds like the route cause for the oiginal seizeure wasn 't found - it is possible that you have saws either set too lean or may have air leaks - all this should have been checked when the new P&C were fitted.

 

It is also possible you have other issues - old fuel mix being used? dodgy fuel? Operators that like fiddling with the carb H screw?

 

Difficult to tell but any good tech would pressure and vac check the saw after rebuild and then tach the saw to around 14100 on a 346xp and then re-tach to around 14,500 after 15 tanks has been run through it!

 

Thats what I think:thumbup:

 

Thats the words of a good tech:001_smile:

[Eddy_t]

Hi All I;ve got problems with two of my 346xps. One is about 3years old and about three months ago started to become difficult to start and started cutting out when idling.

Took it to local dealer who said piston and barrel needed replacing Charged me £300 for doing it.

The second one is just over a year old and within a week of the other one developed exactly the same fault. Another £300 and I had them both back in service

That was back on November.

Both have done less work than usual since then due to the bad weather.

Last week one developed exactly the same symptoms as before and today the second one siezed solid. If freed off when it cooled but is now showing the same symptoms Ie hard to start and cutting out.

We are always meticulous with oil mixes and have run them at 120ml of sthil oil per 5 litre rather than 100ml since the last problems.

Filters are cleaned daily, Plugs changed about once a month.

Is it just our bad luck or is there a problem with 346's. Should I be looking at bad techniques from the lads.

Don't want to waste another £600 at the dealers so I'm looking at swapping to MS261's

Any comments or suggestions would be welcome.

 

I've never had a problem with mine, I've run mine on 50:1 petrol and aspen fuel, sounds like a carb problem, or as spud says an air leak

 

 

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[TreeswingerPerth]

I've got 2x 346 xp and xpg both done a power of work . I suspect you have some other problem as Spud says , you need a clued up tech ASAP mate .

[Cut4fun]

NE 346 cant be tached at 14.5K without changing out the blue coil to a black one (then IMO it would be way to lean for a STOCK NE 50cc 346). The blue ones are rev-limited here to 14.1K and I try to keep them adjusted on the safe side at 13.8K.

 

OE 346 45cc were 14.7K stock.

[GardenKit]

I,m pretty much with Spud on this one.

 

These air leaks we all talk about are in fact pretty rare on newish saws, and I have my doubts they caused the initial failures, but when the saws first siezed the seals could have been 'cooked' so could have caused the second failure if not spotted on a pressure/vac test.

 

As Spud says, the use of stale fuel will cause this. It causes the saw to run weak.

 

But if your fuel is always fresh then I would expect that you have a 'fiddler' in your camp! They are quite common, ' a little knowledge is a dangerous thing'.

[GardenKit]

Or Tesco petrol.

[Stubby]

NE 346 cant be tached at 14.5K without changing out the blue coil to a black one (then IMO it would be way to lean for a STOCK NE 50cc 346). The blue ones are rev-limited here to 14.1K and I try to keep them adjusted on the safe side at 13.8K.

 

OE 346 45cc were 14.7K stock.

 

As you rightly say blue coils are limited . I have a black one in mine but it has been ported by spud so revs out high .

[spudulike]

As you rightly say blue coils are limited . I have a black one in mine but it has been ported by spud so revs out high .

 

C4F is correct - the standard machine limits the revs to 14.1Krpm with a blue coil - that is the first thing to go when I mod 346XPs, Just makes taching a lot easier as the tach goes all over the place when the limiter is hit.

 

Standard machine - I was probably a bit high in my estimation - must be in porting mode - 13,800 - a tad under limiter max would be best - difficult to do by ear as the limiter can fool you in to thinking all is fine - best done with a tach on these machines - start low and build up revs to the limiter cuts in and then back it off!

 

I have just done a MS390 - it has a top cover for a decomp but no decomp on the cylinder so the cylinder has been replaced - one of the seals was badly gone - very hard and leaking excessively. The saw had seized and it was pretty obvious that it was a lean seize down to the fact the seal hadn't been replaced on the first rebuild.

 

It is possible that both of the OPs saws have leaks - the carb boots are prone to this and worth checking but again - a decent tech would do this on rebuilding a machine:blushing: