Blower-Mister Idle

[lefty]

Cifarelli
Model: M1200US
Serial: 03M78FI0119

This came to me for a quick mini service from a friend. It's a mister type blower. I did a spark plug and fuel filter, inspected the exhaust port for carbon (there was none). Washed and oiled the filter (at his request) and I cleaned the dirt off and it starts on the first pull. But it seems to idle too high. It idles at about 3800 and tops out at 6600 (I think that's too high as well). The idle screw is completely backed out so I'm guessing this is a mixture issue? There are red plastic plugs over the adjustment screws that I think I need to pull out to get at the screws but wanted to confirm. There's a high and a low. I'm guessing that the high idle and top end are a result of mixture problems? Any advice is appreciated.

Picture of carb screws
https://photos.app.goo.gl/BZFqB5eVL6o1Wji76

Thanks.

[KE4AVB]

Those EPA plugs are fairly easy to pull. First you line the tabs, takes a good eye. Then using a puller ie 2.5 flat end screw pull the these out. They don't need to come out all the way just enough to release the mixture screw but it is easier if you do pull them all the way. Then using a flat tip straight sided screwdriver that fits through that center hole if these are still semi in place you can adjust the mixture setting.

Note if you fully remove these plugs they only back in one way as those tabs are slanted.

[bgsengine]

before messing with carburetor, something like that I'd start with crankcase pressure/vacuum test and fuel system pressure/vacuum test to eliminate air leaks and fuel starvation issues.. then verify the spark plug correct for the unit. Assuming the adjustments were correct at the factory, they should still be correct for the machine, so I'd generally look for problems elsewhere first before trying to solve it with an adjustment.

[lefty]

Thank you.

Now I've never done this type of test and have to purchase a pump for the test. I did some research on the process and know that I need a way to block off the intake and exhaust for the test. I've been considering one of those mighty pumps for a while because I knew I would eventually need one. I'd appreciate any suggestions for blocking off the ports. Thanks.

[bgsengine]

Thank you.

Now I've never done this type of test and have to purchase a pump for the test. I did some research on the process and know that I need a way to block off the intake and exhaust for the test. I've been considering one of those mighty pumps for a while because I knew I would eventually need one. I'd appreciate any suggestions for blocking off the ports. Thanks.

Port Blockoff - Echo 91041 rubber trapezoid - 2 of those should do for most configurations - (2-bolt ports) and all you do then is loosen muffler/carburetor, wedge the rubber block off in between bolts and snug the screws back down.. units with a separate impulse hose you can hook pressure/vacuum tester to that hose, or better yet spark plug port adapter (Echo 91018 14mm test adapter - there's also 91081 for 10mm plug holes.. or any other size can be fashioned from an old spark plug of the right size, and a barbed hose fitting soldered in after knocking out the ceramic guts) Other block-off ports can be fashioned with some thick gasket material and metal plates (but requires cutting and drilling to size, etc) or thick (but smooth and non-porous) rubber material cut to fit the port & bolt holes, and use the muffler or carb for backing.. as you build up your set of block-offs you likely will find most used would be the trapezoids - and every so often you have to custom fabricate for an odd shape fitment.

[lefty]

Thank you. I'll keep you posted.

[lefty]

This is going to sound silly. Turns out, the throttle cable dislodged from its anchor point. It just slips into something and had come out. Once put back in place, everything ran and responded fine.

I'm kind of glad though that we were thinking leak. Gave me an excuse to order one of those Mity hand pumps, which I've been threatening to get for a while. Should be here today.

Thank you.