Briggs/Nikki Carb Problem

[KE4AVB]

When using an impact air flow rate is important doesn't matter how powerful the impact claims to be if there are line restrictions. A few years ago I brought an AirCat 1150 1300 ft-lb that performed very poorly. After putting an inline gauge at the impact I found that the 120 psi line pressure was dropping to 20 psi during the impact operation. The problem two fold. One I can't really correct as I need the 100 line unless I upgrade it to 1/2" line. The other was the so-called M style couplers and adapters. They simply too restrictive. I now at full pressure after install V style couplers and adapters. I still have line pressure on extended use but just stop a couple seconds and the line pressure recovers. I have yet to see a bolt or nut that I couldn't get loosen through remove several that cross threaded severely.

As the spindles you should remove the pulley nut and knock the shaft as most like they will need replacing anyway. Just how bad shape the rest of spindle is as sometime it is best to replace them.

And yes some of the aftermarket spindles are junk. I went through 5 Rotary spindles last year trying to fix a CUB ZTR fabricated deck before I gave up and just rebuilt the ones I had to start with.

[lefty]

Interesting. I never thought of that. I don't know if the ones I use are M or V but I do know they are the automotive type. I have a million of them and that's just the type of female end that I first put on the compressor so it's the one I've been staying with. I have to put a gauge on there and check it out. I actually was given a pretty awesome compressor yesterday by a relative. It's like 10CFM at 100lbs vs my little 4.9. It's a lot bigger storage capacity as well. Can't wait to set it up but I just need an oil fill cap for it. Thanks for the tip.

[KE4AVB]

Most likely they M style as the V style is a dual purpose high flow coupler that allows both the use of the V and M adapters; although, when the coupler is worn the M style adapters will leak air. Not all M style fitting are made the same either will I found out. Using a drill bit as gauge I found those HF one were a lot more restrictive as were other off the wall brands.

Currently I using a 30 yrs+ Magna Force 25 gal compressor setup here but once I get the crossover wiring between the new service and old service I can install a 60 gal upright compressor setup. The new and old service panels are on the opposite side of the shop. Just got to cut a couple access area to the ceiling; unless, I can get someone to help pulling the wiring drop leads. The air compressor if instaledl on the old service side would the main load as the LED lighting don't need much even when I am using them.

This old compressor can't keep up with my die grinder but has no problem the AirCat as it sips the air when compared to the die grinder. I must upgrade the die grinder as it is an air waster.

[38racing]

Depend where you put the fuel shutoff if you a vacuum fuel pump. If after the fuel pump you might have a leaky diaphragm in the fuel pump.

Also you have gravity carburetor that is fed by a fuel pump that can be a problem too.

No pump. I'll replace shutoff when I do the carb.

[KE4AVB]

The only thing I can think of then is there is a problem with bowl gasket. As BGS pointed out to me several years it only takes a nick or defect to cause problems. It takes a magnifier glass to inspect these. Also make sure the Nikki transfer float assemble is not warp. I haven't seen but is a possible when anything that is plastic. These magnifiers is also what I use to inspect float valve needle tips.

I also got 5 of these bowl gaskets last year that had a manufacture defect in them and had to get them made up by my distributor.

[lefty]

Just wanted to thank everyone and close this one out. I converted over to the big daddy fittings and those nuts blew right off. Replaced the spindle and threw some new blades on it (they came in a set for $26). I tapped the holes out of fear of breaking the old bolts while trying to self tap them. I put some Loctite on them to be safe.

The hardest part was getting that deck back on but I managed. By the way, the spindle with the mangled threads had a regular nut on it. Not one of those flanged nuts. So obviously the last person who had the blade off pulled some shenanigans. I was able to get the right nut for a couple of bucks bringing the total parts cost up to about $60. So everyone was happy. Thanks again.

[KE4AVB]

Glad to here that changing to hi flow couplers and adapters brought new life to your air tools. Those industry standard "M" fittings have been around for decades but they just can't provide the air the newer high power tools need. What worse is the clones of the Milton "M" sets are not made to spec. Even older tools work better when they get the air flow they need.

On those improper nuts I have seen a lot make shift repairs. As the MTD spindle shafts most are threaded 5/8"-18 if IRRC as if the nut doesn't start easily I just clean up the threading. And the use of old screws is usually a break awaiting to happen. Most times I don't even get them out is one piece due metal corrosion.

Sometimes it takes having a part made like the variable speed pulley I just rebuilt where MTD don't even sell the inner shaft for the $170 pulley assembly. I know it may not be as hard as the original but mower owner wasn't going to spend the $170 for the pulley assembly. He insisted it was a deck problem and wanted deck belts. When he couldn't get it to work he brought the mower in and I found the variable pulley jammed due to bearing failures. The customer will inform that it is just a patch and that it will not last a long as the original part.

[lefty]

Thanks for that info. I'll be getting it back soon to do oil and sharpen the blades. I'll make a point to replace those spindle bolts. Thanks for the heads up.