Tecumseh Primer Type Carbs

#1
Hey all...Using a Tecumseh Snowblower Engine,5hp with the primer bulb Type Carb...which of course also has a Choke..or half a choke as it really is...
Question is..If I eliminate the Primer,Will the Choke actually work?..Being the Blade is not full and not sealing off the Intake?
Or do I have to find/make up a Full sized choke Blade?
 

markus

Well-Known Member
#2
Hey all...Using a Tecumseh Snowblower Engine,5hp with the primer bulb Type Carb...which of course also has a Choke..or half a choke as it really is...
Question is..If I eliminate the Primer,Will the Choke actually work?..Being the Blade is not full and not sealing off the Intake?
Or do I have to find/make up a Full sized choke Blade?

choke plate is the same on those as a standard, They are never full blades like a throttle plate is. Remote primer? Remember you cannot cap off the inlet on one of those without also opening the atmospheric vent to the bowl to roughly 1/16" or you will most likely experience flooding issues. They reduced the size of the vent on primer versions due to the primer acting as a vent when not in use and the reduction helps with velocity/air movement in the bowl reservoir force the shot of fuel into the venturi. I have done some writeups on these in the the past few years on here....

https://oldminibikes.com/forum/index.php?threads/tecumseh-carbs-primer-bulb-vs-non-primer.111055/

this one shows me converting some for recreational style with proper choke lever for header applications

https://oldminibikes.com/forum/inde...rs-to-mini-bike-application-hs-series.164438/
 
#3
choke plate is the same on those as a standard, They are never full blades like a throttle plate is. Remote primer? Remember you cannot cap off the inlet on one of those without also opening the atmospheric vent to the bowl to roughly 1/16" or you will most likely experience flooding issues. They reduced the size of the vent on primer versions due to the primer acting as a vent when not in use and the reduction helps with velocity/air movement in the bowl reservoir force the shot of fuel into the venturi. I have done some writeups on these in the the past few years on here....

https://oldminibikes.com/forum/index.php?threads/tecumseh-carbs-primer-bulb-vs-non-primer.111055/

this one shows me converting some for recreational style with proper choke lever for header applications

https://oldminibikes.com/forum/inde...rs-to-mini-bike-application-hs-series.164438/
Ok Thanks!....But I've seen Carbs for Rototillers etc that have Full Blades,No primer of course... Easy Mod then to Drill the Vent and Cap Off the Primer Inlet....Great! ....WIll read the links you've provided......
 

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markus

Well-Known Member
#4
Ok Thanks!....But I've seen Carbs for Rototillers etc that have Full Blades,No primer of course... Easy Mod then to Drill the Vent and Cap Off the Primer Inlet....Great! ....WIll read the links you've provided......
Ummmm, That picture is of the throttle plate not the choke..... turn it around ;) Engines still need airflow to work, a full choke plate would just flood 58D64C9A-8385-4C61-8DB7-ED2C5B2A6E8D.png
 
#5
Ok..But that's the Choke..See the Spring and the Long Arm?.....Look at this View.
Anyway..Lots of Engines use a full choke Blade..:cool:
Looked at the Carb I have...That is one small Vent Hole!....Going to Pull the Welch plug..I would never trust the Drillings to not get it there..with grease or otherwise...
 

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