50cc chainsaw carb

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Teejay112

Teejay112

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I bought this carb a while ago and realized the pulse was done via fuel lines from crankcase to carb instead of the usual hole in the carb so I ended up using the dremel to create a pulse hole like on the wt series carbs as my 771 was not supplying enough fuel at mid to high throttle when warm so today I decided to use the walbro wt carb repair kit and rebuild my modded chainsaw carb as it was very similar to the wt carbs but for 50+cc I have just taken it for a run and it's great but I now have no primer bulb and only one line from engine to fuel tank and the other acting as a breather

What I want to know is I have a buggy filter and stack and nodded the carb removed the choke while it works and runs better than the 771
How will I generally prime it now any ideas ???

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Put the choke back in and pull. Not to sound like a peepee but that's how you started the saw and well 2 strokes for years before primer bulbs. And besides that the choke provides minimal airflow disruptions to the workings of a carb not even enough that you would be able to tell.
 
Seandonato73 said:
Put the choke back in and pull. Not to sound like a peepee but that's how you started the saw and well 2 strokes for years before primer bulbs. And besides that the choke provides minimal airflow disruptions to the workings of a carb not even enough that you would be able to tell.
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Trust me I wanted to put it bk in but I tapped the holes for m5 bolts and also I cant find it I think I threw it out I know the day will come where I'll need to prime it and no bulb and no choke means I'll probably have a problem but this carb has really unleashed the beast I just didnt wanna fork out the cash for a new carb before I tried this one the 771 I have has a loose throttle shaft this one is solid for now and uses the same internals as a walbro
 
Seandonato73 said:
There are sliding style choke plates that some stuff uses that may be able to be adapted. What model of carb is it? You may be able to Ebay parts on the cheap for it.
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The brand is tomking it's literally a walbro clone but bigger bore and no bulb etc so far it starts within 2 pulls you can see it pulling fuel in when you pull the starter and I think I've seen the v stack with a sliding choke on rcmodelz before thanks for mentioning that I wont get it yet I'll wait and see if it will start as easily as it does now down the line
 
Teejay112 said:
The brand is tomking it's literally a walbro clone but bigger bore and no bulb etc so far it starts within 2 pulls you can see it pulling fuel in when you pull the starter and I think I've seen the v stack with a sliding choke on rcmodelz before thanks for mentioning that I wont get it yet I'll wait and see if it will start as easily as it does now down the line
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You have to be careful about those though ,if they don't seal proper ,they could allow dust & dirt get sucked into the carb.,
I am not saying nothing bad about them ,I am just saying to pay attention an monitor it closely!
You might can try something like this!

https://www.ebay.com/itm/4X-Snap-In...223427?hash=item23c0022d03:g:nhoAAOSwtYtdFfZA
 
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cbaker65 said:
You have to be careful about those though ,if they don't seal proper ,they could allow dust & dirt get sucked into the carb.,
I am not saying nothing bad about them ,I am just saying to pay attention an monitor it closely!
You might can try something like this!

https://www.ebay.com/itm/4X-Snap-In...223427?hash=item23c0022d03:g:nhoAAOSwtYtdFfZA
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I know I heavily loctited the bolts red loctite also that part is what I was thinking but I replaced the bottom half of the carb with the bottom from the 771 so it only has the one nipple for fuel in and I modified with a small dremel bit so the pulse from the isolator does its job it's working so far I'm just worried about when it's not primed the primer bulb in the link would be perfect except theres nowhere on the carb to put it unless if bridges between the fuel line and tank as theres literally only a fuel line on the carb and pulse is handled via the isolator and carburetor body so far it's good I'm getting wheelies and into the powerband even quicker than before so far the downside is my idle is at 3800 to 4000 rpm on idle as this carb tends to bog after you let off full throttle only for a second then it regains its rpm I'f I tune it to say 3500 rpm on idle after letting off the throttle it will stall and it's not a lean stall it's as if the carb doesn't transition from full to 0 throttle straight away it keeps pumping in fuel for a second causing it to bog if you get what I mean
 
mark35 said:
I used to have a tilliston carb I got from mmr model tech and that had a separate primer bulb like the one cbaker65 posted above, I billed a hole in the rollcage alloy top plate and mounted it there.
In fact I still have the cage
Said hole???View attachment 52633
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Nice Baja just when I'm happy with mine someone goes and posts a pic like that next time gimme a short rope to hang myself with ?lol how was the carb performance wise and also would the primer work by pulling fuel from the tank straight to the carb like say basically replacing just the fuel line as that's literally all I have one line tank to carb no return line no pulse line pulse is internal
 
Teejay112 said:
Nice Baja just when I'm happy with mine someone goes and posts a pic like that next time gimme a short rope to hang myself with ?lol how was the carb performance wise and also would the primer work by pulling fuel from the tank straight to the carb like say basically replacing just the fuel line as that's literally all I have one line tank to carb no return line no pulse line pulse is internal
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LOL...that is the way I feel ,I see someones shiney hopped up sh**t ,an I want to shove my stuff back in the dirty shed!...
 
Teejay112 said:
Nice Baja just when I'm happy with mine someone goes and posts a pic like that next time gimme a short rope to hang myself with ?lol how was the carb performance wise and also would the primer work by pulling fuel from the tank straight to the carb like say basically replacing just the fuel line as that's literally all I have one line tank to carb no return line no pulse line pulse is internal
Click to expand...
I'm not sure on your carb because the tilliston had a return but the primer blub just goes in the fill line.
So to be clear, feed line from tank into the blub then out to the carb. Bosh? job done?
 
cbaker65 said:
LOL...that is the way I feel ,I see someones shiney hopped up sh**t ,an I want to shove my stuff back in the dirty shed!...
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It's funny but it is encouraging
mark35 said:
I'm not sure on your carb because the tilliston had a return but the primer blub just goes in the fill line.
So to be clear, feed line from tank into the blub then out to the carb. Bosh? job done?
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Thanks so that's exactly what I need then so far it is priming with 2 to 3 pulls and firing on the first pull when the powers on ?
cbaker65 said:
LOL...that is the way I feel ,I see someones shiney hopped up sh**t ,an I want to shove my stuff back in the dirty shed!...
Click to expand...
Theirs are always clean aswell lol I cant be bothered to clean mine unless I'm working on it and even then it's only what I'm working on I clean
 
I do recall that single feed carbs will not valve out bypass fuel if trying to use a bulb primmer. Plug on new fuel line and see if you can pass air through it . If you can not move any air a primer bulb will do nothing for you
 
lorraine said:
I do recall that single feed carbs will not valve out bypass fuel if trying to use a bulb primmer. Plug on new fuel line and see if you can pass air through it . If you can not move any air a primer bulb will do nothing for you
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lorraine said:
I do recall that single feed carbs will not valve out bypass fuel if trying to use a bulb primmer. Plug on new fuel line and see if you can pass air through it . If you can not move any air a primer bulb will do nothing for you
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I was thinking the same thing ,like a vapor lock!
 
Chain saws have the fuel tank so close to carb and almost same fluid level so it does not take much to pull fuel . I do not think he will find a primmer will move fuel with that tree killer carb
 
All the way up to 60cc most newer stuff has a primer bulb built in. Cant say I've seen anything like that on bigger displacement. But all that I have encountered have been 2 fitting style carbs. Would be interesting to see if an inline bulb would work.
 
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