Jiffy Model 30 With Tecumseh - Carb Question

[iliketrout]

I have a new-to-me Model 30 with the 3hp Techumseh. Starts first pull all day long in my garage, and also in warmer temps.

In colder temps (like -15 on the weekend) it wouldn't start while the choke was on. Had to be no choke and 1/2 throttle and it would fire up. However I would need to keep priming in order to keep it running. It didn't seem to be able to warm up and to get through a hole, my dad had to keep priming as I was drilling.

I'm thinking there is no fuel line blockage because it runs like a dream in warmer temps. I'm going to pull the fuel line and blow it out just in case, but I'm wondering if I rebuild the carb if I'll just have the same results, or if this is a jet adjustment issue. I know these Model 30's were tempermental and you had to be quite precise with the screw setting.

Any thoughts from fellow Model 30 owners?

Further info: brand new plug, seafoamed in the spring right after I purchased it and I'm running 94 octane with a 40:1 oil ratio.

[Fwee6]

I had a similar but not identical issue last month...


First, I thought it was old gas, so I dumped it and put in Trufuel (I'll never mix gas again). Problem continued. Spark plug and all other simple fixes checked out.

Second, I jumped on Youtube and reviewed the jet tuning tutorials for the Jiffy 30. In 2 mins, I had it running better in the garage at -15C.

Third: out to the lake the following weekend to run it at -20C that morning. It's never cut so well. It barked!

Conclusion: the low jet setting was off some, and TruFuel @ 40:1 is the cherry on the cake. When in doubt -- Youtube has yet to fail me for mechanical fixes.

[Who Da Fisherman]

Mine since day one has ran the way yours is till I just took it in for servicing.
Not sure what he did (something about some plate inside was wearing?...) but took it out after and it works great. Maybe try a small engine mechanic, the guy who did mine did it as a favor.
WDF

[Double_A_Ron]

Had similar issues with mine last year, I adjusted the low and high idle jets on the carb and it helped, then this fall I threw in fresh gas and a new spark plug and it's a brand new machine. One pull starts, barely have to choke, 2min warm up and can cut 20 holes non stop. I'd try the easy fixes before taking it to a small engine guy, especially with only two weeks left in the season, once April hits by all means let someone work on it.

[iliketrout]

Thanks all...good ideas to try. I'll try the jets first and then a rebuild if that fails.

[Phil]

In addition to Seafoam in the tank I removed both jets (Count how many turns it takes to close them so you can return them to the original adjustment) and sprayed some Seafoam into the carb through the jet openings. I let it sit for a day before firing up. I also found I needed to adjust the jets from their previous settings after the Seafoam treatment. It definitely ran better.

Don't be afraid to try lots of jet adjustments while on the ice just remember what you did so you can return to the previous setting. I used 1/2 turn at a time until it was running like I wanted. Adjust, run it under load and adjust again until you're happy.

Good Luck,
Phil

[splake0]

Originally Posted by Phil

In addition to Seafoam in the tank I removed both jets (Count how many turns it takes to close them so you can return them to the original adjustment) and sprayed some Seafoam into the carb through the jet openings. I let it sit for a day before firing up. I also found I needed to adjust the jets from their previous settings after the Seafoam treatment. It definitely ran better.

Don't be afraid to try lots of jet adjustments while on the ice just remember what you did so you can return to the previous setting. I used 1/2 turn at a time until it was running like I wanted. Adjust, run it under load and adjust again until you're happy.

Good Luck,
Phil

I had the same issue. There is a ball inside the carb that sticks. I screw the left jet all the way in and remove the right jet. Give is a shot of air (low pressure). This frees un the ball. Put the screws back to normal position and your good to go until the ball sticks again. The permanent fix is a new carb.

[yetiseeker]

Fuel, plugs, seafoam, etc all good suggestions.

If that still doesn't work, a few years ago I had the same issue by the sounds of what you're encountering.

Turns out I had a pin hole sized hole in the fuel diaphragm and needed to be replaced. After 15 years or so in service, the rubber started to wear out and once replaced with a new diaphragm, ran like new again.

Going on 17 or 18 years with the same old model 30 Jiffy!

[RiverHawk]

I have this exact same auger and had the same issue. It runs like a top in the heated garage, and by the time I'm at the lake I pulled so many times I blew up the recoil assembly. I then paid Lawnmower Hospital $250 for a new assembly and a tune up. It ran great again in the garage but the recoil blew yet again on the lake! At that point I gave up and bought an Eskimo 71. That thing is amazing! I have recently ordered and replaced the recoil on my jiffy again and it runs good, so I guess it'll be a back up now. Also I mixed closer to 50:1 on the jiffy and it seems to like it a lot better. Some guys swear by jiffy but I gatta say that my Eskimo runs 100 times smoother, faster and starts when it's cold!

[gtr]

Seems they never cause grief in the garage. Carb kit probably the answer.