Saws with no start throttle lock

[Woodsmith1]

A question to all the experienced folks round here. I have recently experienced a couple of saws that have no throttle lock for starting. Neither the plastic button on the handle to lock the throttle trigger in a half throttle position nor some interlock through the chock lever. The manual also doesn't mention and special starting procedure. Starting such a saw is difficult if not impossible cold, as with the choke pulled, the throttle butterfly is open but a millimeter or two so very little flow can pass by. Using a wire wound round the throttle finally gets it started. When warm though I am able to start the saw as is. Has anyone else come across saws wholly lacking the throttle-set-for-start function? What surprises me is that when the choke is pulled on these models, the choke tab interlocks with the little throttle plate so that the chock is reset after starting when throttle is given. The way the little tab interlocks pushes the throttle open by a minuscule amount, certainly nothing noticeable, but if a small nub were to be added to the tab (I might try welding a little spot on it), that would resolve the whole issue and allow the throttle to be held open sufficiently when starting with choke. The saws I'm specifically talking about are the Chinese 52cc models and the more 'legit' Lidl sold Florabest FBKS 52. Any ideas what the intention is with this type of starting system? Is it a design oversight or is starting possible, just requiring many pulls? One surprising thing is that on my other 52cc saw, in the marketing photos the throttle lock is clearly shown as a little black plastic nub on the side of the handle. On my saw, there is a small circular die mark where the part would go, but no hole is bored, even though the throttle trigger pieces inside have a corresponding hole where the lock would grip them in starting position. Curious to hear any ideas or theories!

 

[Andyshine77]

If the throttle is cracked open when you pull the choke and stays that way until you pull the trigger, that is the automatic throttle lock or fast idle, and is how most newer saws are.

 

[cre73]

I have a couple I dont like using a clamp ot wire so I end up looking like a monkey F'ing a football while starting them, They both have 170+ compression with no compression release.

 

[Woodsmith1]

If the throttle is cracked open when you pull the choke and stays that way until you pull the trigger, that is the automatic throttle lock or fast idle, and is how most newer saws are.

As I wrote though, through the stroke of pulling the choke out, the choke 'arm' on the carb slightly bumps the throttle 'plate', getting 'caught' behind it in order to be able to release the choke when the throttle is squeezed, but with the choke fully deployed (this is the only state it has on-off), the throttle is UNCHANGED from its practically closed idle state. So NO, it isn't the typical choke holds half throttle new saws use (I have one of those too)!

 

[Woodsmith1]

I have a couple I dont like using a clamp ot wire so I end up looking like a monkey F'ing a football while starting them, They both have 170+ compression with no compression release.

Are you able to get them started reliably without propping open the throttle, it just taking tens of pulls, or is it sometimes impossible without jerryrigging it?

 

[Jethro 2t sniffer]

Easy man rest the saw on a log on the bar and yank the cord with left hand while holding the throttle open with right hand easy peasy. And with a smaller saw you dont really need to rest the bar on anything

 

[Andyshine77]

As I wrote though, through the stroke of pulling the choke out, the choke 'arm' on the carb slightly bumps the throttle 'plate', getting 'caught' behind it in order to be able to release the choke when the throttle is squeezed, but with the choke fully deployed (this is the only state it has on-off), the throttle is UNCHANGED from its practically closed idle state. So NO, it isn't the typical choke holds half throttle new saws use (I have one of those too)!

Right, good luck with that. I was trying to help, but it is difficult to decipher what you're trying to say, plus you gave me a somewhat snotty response.

 

[Woodsmith1]

Right, good luck with that. I was trying to help, but it is difficult to decipher what you're trying to say, plus you gave me a somewhat snotty response.

Sorry Andy, no arrogance intended, far from it, just trying to make clear to any readers what configuration I'm trying to explain, as it is quite difficult to put a convoluted 3D interplay of tiny parts into words that are understandable. Look forward to any input anyone has and don't wish to step on anyones toes, especially not someone like you who offered an early opinion on the matter. Best,

 

[NSEric]

I have 2 of those Chinese saws.
Mine start really easy with the stock set up, there's nothing wrong with it.
Try adjusting the carb a little richer and bumping the idle speed a touch.

 

[buzz sawyer]

Sorry Andy, no arrogance intended, far from it, just trying to make clear to any readers what configuration I'm trying to explain, as it is quite difficult to put a convoluted 3D interplay of tiny parts into words that are understandable. Look forward to any input anyone has and don't wish to step on anyones toes, especially not someone like you who offered an early opinion on the matter. Best,

Can you get photos of the carb to show what you mean? On some older saws with no fast idle provision, there was a spring around the handle. You pulled the spring up around the throttle trigger to hold it open for cold starts. I don't know if this was stock or not but it worked.

 

[cre73]

Are you able to get them started reliably without propping open the throttle, it just taking tens of pulls, or is it sometimes impossible without jerryrigging it?

I hold the throttle with one hand kneel on the saw so it wont move around while pulling and pull like a mother. I have them both to the point I can start them in about five pulls. This was a learning experience with both these saws. These are both old magnesium case saws so no worries about my fat but crushing plastic cases.

 

[Old2stroke]

Like you have discovered, 2-stroke engines are damn near impossible to start when cold with a closed throttle. It's possible that somewhere in the production, the throttle-up interlock button on the handle was left out, would it be possible to fabricate one? Your idea of adding a tab to the choke mechanism should work as well, whatever is easiest to do that will hold the throttle partially open will work.

 

[Woodsmith1]

Like you have discovered, 2-stroke engines are damn near impossible to start when cold with a closed throttle. It's possible that somewhere in the production, the throttle-up interlock button on the handle was left out, would it be possible to fabricate one? Your idea of adding a tab to the choke mechanism should work as well, whatever is easiest to do that will hold the throttle partially open will work.

Will go on to make the mods to add a throttle hold open. It seems I can order the button/pin holdopen, would just need to drill a hole in the handle where there is a sign the mold was modified to remove the feature and add a cylindrical piece of plastic to act as a guide for the button. Any idea how they could have decided to remove this feature, sure cost, but did they consider it still reasonable that the saws would be capable of starting AT ALL without a throttle holdopen?

 

[Woodsmith1]

In the pictures below you can see first the sales media with the button, then real saws missing it, with a faint circular burr line where it used to be:

Schter Hold

• Woodsmith1
• Oct 26, 2019

Schter No But

• Woodsmith1
• Oct 26, 2019

Schter No Button

• Woodsmith1
• Oct 26, 2019

 

[Jethro 2t sniffer]

Not a bad saw for the price those ching chong specials. I got 5 years of absolute newbieness and dull chains and still went well. Sold it on for half what I paid.

The soft start feature they have is quite nice.

Thinking about it mine never had the lock eather but it didn't need it

Watch the air cleaner mine leaked like a British car oh an be kind to the bar studs

 

[Woodsmith1]

Not a bad saw for the price those ching chong specials. I got 5 years of absolute newbieness and dull chains and still went well. Sold it on for half what I paid.

The soft start feature they have is quite nice.

Thinking about it mine never had the lock eather but it didn't need it

Watch the air cleaner mine leaked like a British car oh an be kind to the bar studs

What do you mean by the soft start feature? Like a spring assist in the recoil starter? Did you notice if the choke lever interfaced with the throttle to give a wider throttle at startup?

 

[Jethro 2t sniffer]

I honestly dont remember but I'm pretty sure it was just an old school choke and started with the idle after the first pop.

Yeah after thinking about it it was just a choke

Yes the spring assisted starter. Be nice too it my mate broke his. When warm it will start with your teeth if you wanted too lol

 

[Woodsmith1]

I honestly dont remember but I'm pretty sure it was just an old school choke and started with the idle after the first pop.

Yeah after thinking about it it was just a choke

Yes the spring assisted starter. Be nice too it my mate broke his. When warm it will start with your teeth if you wanted too lol

The ones I got don't have that feature, wasn't aware it was wide spread among the china clones. Would you deem it a serious improvement over the tried but true old start system? Comfort, ease of start? Is it really that much of an improvement? You just pull straight with equal force and at some point is just pops off and turns over right?

 

[Jethro 2t sniffer]

Yeah na wouldn't worry eather way it's only 52cc. It's a weakness really so probably better without it.

All the ones I have seen down here had it I just assumed they all did

 

[Woodsmith1]

Yeah na wouldn't worry eather way it's only 52cc. It's a weakness really so probably better without it.

All the ones I have seen down here had it I just assumed they all did

As a side note, any idea why starting the 52cc without compression release is fairly easy, but a 56cc Solo I have is almost impossible to pull start without clicking the release on. How can the difference be so stark, the increase in displacement is negligible and I doubt the compression ratio can be so different either?