50cc chainsaw carb

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
Top Dead Center said:
I think this primer bulb will do the job. If you find yourself in need of a choke, slip a ziploc sandwich bag over the filter and pull the engine over until it blips, then remove the bag. Should be good to go.
Click to expand...
we have one of those here at shop, Made out of silicone stuff for nitro! pretty sure gas will mess it up,
Seandonato73 said:
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.
Click to expand...
I meant the saw that carb came off of, Last time I seen one like that was on a OLD remington red saw....OLD!
 
Last edited:
It shouldn't vapour lock because theres still a breather in the tank I'm sure it will work and this carb is what my engine needed it goes from idle to wot without any issues at all all the time and it seems to be alot more punchy than the carb I had before so far I'm able to prime it by just pulling the starter about 5 times it sucks the fuel through on it's own obviously not as quick as a primer bulb would m
 
Tried starting it this morning took about 20 pulls so I decided to put the 771 back on its chokeless but it's got a primer bulb start up first pull every time taking it out today to see if it still bogs down I've changed all carb gaskets diaphragm filter even checked under the Welch plug to see if there was dirt in the high mid and low outlet nothing so looks good so far I guess
 
Seandonato73 said:
It's a shame you lost your choke components for your chainsaw carb.
Click to expand...
Yeah never thought I'd even need the carb but so far the 771 seems ok since having a full stripdown and rebuild I was never able to have the low needle 1 1/2 open and have the engine idle even tho that's default but now i can so that's a start I'll run it in an hour and see
 
Have you tried tilting your rig back with the front wheels off the ground for the first couple pulls ,like
in a 30 degree angle ,some times the fuel will rush into the lines faster!
If I am not mistaking ,over the years that I worked on stuff ,I think that I had seen a couple carbs that had an actual
lever on the accelerator pump plate ,I think that it was an old weed eater or blower that had it!

I have a big box of carbs ,I may have one ,I would have to go look in my shed!...:cool:
 
Last edited:
cbaker65 said:
Have you tried tilting your rig back with the front wheels off the ground for the first couple pulls ,like
in a 30 degree angle ,some times the fuel will rush into the lines faster!
If I am not mistaking ,over the years that I worked on stuff ,I think that I had seen a couple carbs that had an actual
lever on the accelerator pump plate ,I think that it was an old weed eater or blower that had it!

I have a big box of carbs ,I may have one ,I would have to go look in my shed!...:cool:
Click to expand...
I didnt try that I did put the original carb back on I've found once the engine warms up I lose power it bogs transitioning to full speed so I think I could have a worn piston ring because the carbs fine for 10 minutes then it starts to run like theirs no fuel in the tank the idle stays the same but give it gas and it bogs like theres no fuel getting through
 
Teejay112 said:
I didnt try that I did put the original carb back on I've found once the engine warms up I lose power it bogs transitioning to full speed so I think I could have a worn piston ring because the carbs fine for 10 minutes then it starts to run like theirs no fuel in the tank the idle stays the same but give it gas and it bogs like theres no fuel getting through
Click to expand...
I had that with my losi?? would be fine for 10mins then start to bog down when I was accelerating ? changed manifold and it went away. So check your gaskets and manifold. There may be a leak from heat warping ???
 
Teejay112 said:
I didnt try that I did put the original carb back on I've found once the engine warms up I lose power it bogs transitioning to full speed so I think I could have a worn piston ring because the carbs fine for 10 minutes then it starts to run like theirs no fuel in the tank the idle stays the same but give it gas and it bogs like theres no fuel getting through
Click to expand...

That maybe in your needle settings ,or an issue with the carb itself!
 
dougstar said:
I had that with my losi?? would be fine for 10mins then start to bog down when I was accelerating ? changed manifold and it went away. So check your gaskets and manifold. There may be a leak from heat warping ???
Click to expand...
Could it be because I'm using those thick white gaskets / spacers ? I wonder I will have to have a look when I'm in I know it's not between the carb and isolator so maybe between the isolator and cylinder it's an alloy isolator I'll take the whole top end off tonight and order what I need gaskets etc tomorrow hopefully it's not the piston and ring but what you said makes sense
cbaker65 said:
That maybe in your needle settings ,or an issue with the carb itself!
Click to expand...
Could be the other carb worked fine but was hard to start and this ones perfect for 10 minutes I've rebuilt it new gaskets diaphragm etc new metering needle still the same so I'll tear it down and look at the piston ring and all carb and isolator gaskets
 
dougstar said:
theres the problem........took mine of and now there are no more issues(y)
Click to expand...
Ok hopefully I have a plastic isolator indoors but the alloy one isnt taking any heat the plastic gaskets are 3mm thick should I swap those out for standard gaskets too?
 
Teejay112 said:
Ok hopefully I have a plastic isolator indoors but the alloy one isnt taking any heat the plastic gaskets are 3mm thick should I swap those out for standard gaskets too?
Click to expand...

Are you putting the air filter assembly back on afterwards each time ,because the air box helps the fuel draw
into the engine?
 
ditch the alloy manifold and those thick plastic gaskets(y)
put the stock back and see how much better it will run(y)
Teejay112 said:
Ok hopefully I have a plastic isolator indoors but the alloy one isnt taking any heat the plastic gaskets are 3mm thick should I swap those out for standard gaskets too?
Click to expand...
 
dougstar said:
ditch the alloy manifold and those thick plastic gaskets(y)
put the stock back and see how much better it will run(y)
Click to expand...
I have ordered a 998 carb the one with the accelerator pump and gaskets should have it tomorrow I did check my engine also piston is fine cylinder is fine I changed the ring anyway so just waiting on that carb and gasket set then I basically gotta break in the new ring
 
Changed the isolator replaced the thick white gaskets with flat ones adjusted the metering lever inside the 771 carb lifted it a little bit idled it for 5 minutes drove it around quarter throttle 10 minutes lots of wheelies no power loss the 998 carb arrives tomorrow morning cant wait to see how it runs
 
Back
Top