Welch plugs

[txmowman]

Proper welch plug replacement does not flatten the dome but rather is peened around the edge. Harbor Freight sells a leather punch set. Get one of these for less than $10. There is one that fits the larger welch plug perfectly. Grind the sharp edge off of the punch, install the welch plug and give it a gentle but firm wrap with a small hammer and you’re done.

 

[StarTech]

Proper welch plug replacement does not flatten the dome but rather is peened around the edge. Harbor Freight sells a leather punch set. Get one of these for less than $10. There is one that fits the larger welch plug perfectly. Grind the sharp edge off of the punch, install the welch plug and give it a gentle but firm wrap with a small hammer and you’re done.

That is the very reason the Kawasaki Nikki twin barrel carbs are losing their welch plugs. They are just peened around the edges then they are easily getting loose and falling out.

Personally I don't like having to replacing $6 welch plugs because of this. Sometimes I get lucky and they fall out while cleaning the carbs.

 

[hlw49]

I like to put fingernail polish over it

 

[StarTech]

And I have seen jets to clogged with whatever OEMs used to seal them if used internally; especially 2 cycle cube carbs.

 

[hlw49]

And I have seen jets to clogged with whatever OEMs used to seal them if used internally; especially 2 cycle cube carbs.

notice I said over it

 

[StarTech]

Apparently you have never worked on a 2 cycle cube. Some OEMs will use sealant on the welch plugs inside the metering chamber which over time flakes off and clog jets and check valves. This why I have to look over the cubes with a loupe to see if this stuff is clogging things.

Outside the fuel system is fine but not inside the fuel system.

 

[Tiger Small Engine]

I like to put fingernail polish over it

Very rarely do Welch plugs fall out. Replace, slightly peen, and hit it with fingernail polish and you are set.

 

[RevB]

Have a scag tiger cat 52"
Kawasakie FX691V with only 272 hours.
It started surging at idle some time back but ran at full throttle just fine. I didn't think too much of it since I don't use it at idle anyway, I think I just learned the hard way that I should have.
Recently started using oil. Oil has always been changed at 50 hr. with full syn. oil. 10W-40, pretty much used in hot weather only.
Last mowing the engine lost about half of its horsepower and sounds different but not a full blown knock.
Did some research and found out about surging issues caused by blown welch plugs so I look and sure enough I have two on top of the carburetor that are blown out. Unfortunately this means I've been running it with unfiltered air being sucked in which has most likely got the rings.

I was attempting to do a compression check but I can't find the correct fitting. The spark plug hole is a 9/16'-18 and my compression tester only has metric adaptors such as 12, 14 and 18mm. I've looked online and cannot find a compression tester with a 9/16" adaptor. I've called every parts store in two cities, and they all carry metric thread testers only.

Would appreciate any information on where to find a compression tester with the correct fitting.

Most likely will be ordering a rebuild kit and doing it myself, never rebuilt a Kawasaki before, any suggestions on the best place to get a quality OEM kit and a shop manual?

I guess it's too hard to fire it up in idle and when "surging" and place both thumbs over the holes and see if it smooths out.....

I'll bet the oil issue is unrelated.

 

[JoeKarpowski]

I have the same motor on my Toro SS5000, and it recently started surging while idling. Also, on occasion, it will blow a puff of oil smoke when I start it after it's been sitting for a while. Other than that, the motor runs fine. I know zero about welch plugs, what/where are they and how do I check them? TIA

 

[Auto Doc's]

Hello JoeKarpowski,

Minor surging at idle is a sign of a dirty carburetor internally. The carburetor would need to be removed and properly cleaned. If you want to attempt this, I can only recommend watching some videos of people who work on small engine equipment for a living.

Sources: Teryl Fixes All (Goofy guy, but knows his stuff). James Condon generator repair is the most thorough one I have noticed when it comes to carburetor cleaning. Donyboy73 who is very good with most small engine concerns.

Too many people want to play with adjustments such as the governor setting. The governor has nothing to do with a surging issue. The governor is only there to control the engine top running speed so it will not blow itself apart mechanically.

A puff of oil smoke when starting is usually the first sign of worn intake valve seals. If it only happens after sitting for a while, I will call that normal, especially if it has high hours. If it happens every time you start, then it's time to replace the valve seals. The quality and type of oil can also contribute to an initial startup "puff" of smoke.

My own preference is to use only conventional 10W30 or 10W40 in any air-cooled 4-stroke small engine.

We would have to see a picture of your carburetor to give you a truly accurate description or a location of the welch plugs. The product information off of the engine label is important for a correct data match. Toro did not build the engine, just the chassis.