• Advertisement

This year is full of strange engine problems!!

Use this forum to discuss small engines, and the equipment or machinery that they power. This is the main section for any technical help posts and related questions.

This year is full of strange engine problems!!

Postby dart451 » Fri Aug 17, 2018 11:13 am

I have a customers Craftsman tractor, with a Tecumseh OHV17 204605B engine. Yes, I scavenged this tractor 917.252502 and put a good Tecumseh engine that I had laying around. The customer has been using this arrangement for a number of years and now the carb started running lean, he had to have almost full choke. So, he asked me to throw a carburetor on it. I am on my SECOND new carb, 640330, and both never shut off the gas, air box fills with gas. I did pinch off the fuel and got it to start on the second carburetor but it would run very rich! I made sure the choke was not engaged and I also noticed after it ran for awhile, the intake manifold was dripping water...cold as ice! Never seen anything like this! So, is anyone familiar with these Tecumseh carbs? Could I have gotten another carb that won't shut off the fuel?
Image
dart451
Forum Pro
 
Posts: 479
Joined: Fri Jul 18, 2014 7:14 pm

Advertisement

Re: This year is full of strange engine problems!!

Postby KE4AVB » Fri Aug 17, 2018 12:30 pm

What type fuel are you/he is running. It does sounds you are having a carburetor/intake icing problems with the intake cold enough pro dew on it exterior.

Now the fuel valve not stopping fuel flow is this when it is just sitting without the engine running or just when the engine is running?
,
The truest measure of society is the how it treats its elderly, its pets, and its prisoners.
User avatar
KE4AVB
Forum Pro
 
Posts: 5998
Joined: Mon Nov 04, 2013 11:23 am
Location: TorLand

Re: This year is full of strange engine problems!!

Postby dart451 » Fri Aug 17, 2018 4:06 pm

KE4AVB, with the old carburetor, it only ran with the choke fully on. Now, I have replaced the carburetor twice, each time the carburetor won't shut the fuel off so it's constantly over filling the carb and air filter chamber. And like I said, it's running really rich... I just noticed the intake very cold while it's running! Better A/C than my truck! Fuel? Just fresh gas but you know what? I'm gonna drain the gas and put my own fuel in it. But, still doesn't explain why the carburetor won't cut the flow of fuel...
dart451
Forum Pro
 
Posts: 479
Joined: Fri Jul 18, 2014 7:14 pm

Re: This year is full of strange engine problems!!

Postby KE4AVB » Fri Aug 17, 2018 5:00 pm

The overfill is why I if it was asking if it was while the engine was running that it did this as you might a gravity flow fed by a fuel pump which will not work properly as pressure will pop off the carburetor float needle seal. Also pieces of the fuel line might be blocking the needle closer; old fuel lines can do this easily as they are brittle.

Carb ice is something I am familiar with but don't is on lawn mowers unless the conditions are just right. Personally I have carburetors to ice over @ 3000 ft when flying. It happen once when it was 95F; not a good feeling when your engine starts missing over a large city with no where to land. All you can do is hope the carb heater thaw things out before you run out of air. Carb ice forms when the humidity is high and the air pressure is very low such as in the intake. And alcohol just makes things worst tas it has an extra cooling effect and raise the freezing point temp higher.
The truest measure of society is the how it treats its elderly, its pets, and its prisoners.
User avatar
KE4AVB
Forum Pro
 
Posts: 5998
Joined: Mon Nov 04, 2013 11:23 am
Location: TorLand

Re: This year is full of strange engine problems!!

Postby dart451 » Fri Aug 17, 2018 6:36 pm

It's gravity feed KEA4AVB, no fuel pump. As you can tell, there doesn't appear to be a fuel bowl in this type of carburetor so I'm not familiar how it fills with fuel and shuts off. I drained the fuel and will fill it with some of my known fresh fuel. However, the fuel lines are fairly new...not brittle at all. I think tomorrow I will take apart the original carburetor and see if I can clean it up...at least THAT carburetor wasn't flooding the system!
dart451
Forum Pro
 
Posts: 479
Joined: Fri Jul 18, 2014 7:14 pm

Re: This year is full of strange engine problems!!

Postby KE4AVB » Fri Aug 17, 2018 6:48 pm

The truest measure of society is the how it treats its elderly, its pets, and its prisoners.
User avatar
KE4AVB
Forum Pro
 
Posts: 5998
Joined: Mon Nov 04, 2013 11:23 am
Location: TorLand

Re: This year is full of strange engine problems!!

Postby 38racing » Fri Aug 17, 2018 7:15 pm

You will see that plastic piece held by wire thing is the bowl. Wonder if the fuel was E85. Wonder if someone forgot to install the needle seat.
38racing
Forum Pro
 
Posts: 2287
Joined: Thu Nov 07, 2013 10:12 pm
Location: Ontario Canada

Re: This year is full of strange engine problems!!

Postby dart451 » Fri Aug 17, 2018 7:20 pm

I'll remove it tomorrow and check the seat...does seem like there is no needle in it! Thank you for the literature KEA4AVB!
dart451
Forum Pro
 
Posts: 479
Joined: Fri Jul 18, 2014 7:14 pm

Re: This year is full of strange engine problems!!

Postby Luffydog » Fri Aug 17, 2018 8:59 pm

Yes it's been a weird year for engines. Pulled 10 out with In a week. Some were replacements and some were leaks some were cams some were sumps. Also been kinda strange for the zt-5400 transaxle replaced 3 of those all right hand side and all out of the same make.
Luffydog
Forum Pro
 
Posts: 658
Joined: Tue Nov 05, 2013 11:05 am
Location: No telling

Re: This year is full of strange engine problems!!

Postby dart451 » Sun Aug 19, 2018 7:31 am

Well this is embarrassing! I took the tecumseh carburetor apart and low and behold, the needle and float were sitting in the bowl not seated as it should! It appeared that the float pin had either worked loose from shipping or wasn't pressed into the carburetor allowing the float to literally float inside the bowl. Once I remedied this, the carb worked fine! Thank you all for all the suggestions! Perhaps I need to dig deeper before I start posting on PPETEN.COM!? Course, It's probably cause I like chatting with you guys! lol
dart451
Forum Pro
 
Posts: 479
Joined: Fri Jul 18, 2014 7:14 pm

Next

Return to Technical Discussion Forum

Who is online

Users browsing this forum: Google [Bot], Google Adsense [Bot], RoyM and 1 guest