OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions on Other Engines Victa Mower with a Tecumseh Engine! - slow speed

I got this mower as a trade on another mower as the previous owner got the sh*ts with it and went back to a trusty 2 stroke. He is happy now so that�s all that matters.
I have seen Tecumseh�s before around the scrap yard however most of them were well past their use by date and not worth while trying to repair.
This one is different. I�m sorry I couldn�t find any model numbers for the archives but I have included some pictures of the carburettor set up.
The mower would only kick over with a little fuel down the spark plug hole so I proceeded to do a carby clean.
After a good clean and re-assembly and managed to get the mower going reasonably well but it�s really only going half speed at the very highest rpm. The mower starts first pull now, doesn�t smoke and runs very smooth.
My question is in relation to adjusting the engine speed, if this is in fact possible as I don�t want to stuff it up as the mower has done very little work or could the low speed be due to another common issue with these engines.
I have included some photos of the carburettor and linkage set-up to assist. I am hoping the RPM adjustment is easy like the Briggs Engines!
Thanks Guys.

The maximum engine speed is determined by the governor. The most common cause of low maximum speed is a stretched, missing or incorrect governor spring. I haven't seen the governor spring in your pictures - the only visible spring seems to be the anti-oscillation spring, which runs from the governor arm to the governor's throttle link, in your last picture. If you can post pictures of the serial and model numbers, and the cowl, we might be able to figure out what model it is and look in the manual. Otherwise you will need to look at the speed control linkage, where the speed control cable attaches to the engine, and post pictures of it.

I have attached some photos to assist in the process as I appear to have been looking in the wrong spot for the manual.
I tried looking at a couple of U-Tube Video�s however the linkage set-ups appear to vary and I want to be sure before making any adjustments simply because this seems like a really good engine.

That is helpful - I had misinterpreted the picture I saw before. In the picture below, the spring inside the red oval is the governor spring. The lever in the green circle is the speed control lever. When you move the speed control on the handlebar from slow to fast, the speed control lever circled should move clockwise, and the governor spring in the red oval should stretch:


It appears that the speed control cable is not correctly adjusted. If the black outer sleeve of the cable is slid to the right, by loosening the clamp screw in the top-center of the picture, the lever connected to the cable will move to the right, and the adjustment screw at the top of the green circle will come into contact with the speed control lever. If you then move the cable outer even further to the right, the cable lever will rotate the speed control lever clockwise, and stretch the governor spring further. This will increase the governed speed.

It appears that because of the incorrect positioning of the cable outer, the maximum engine speed at present is being set by the other adjustment screw, slightly to the right of the green circle. This screw actually sets the minimum, or idle, speed of the engine. So, at present the engine only idles. When you correctly adjust the position of the cable outer, it should have the intended speed range.

Just looking at it, something seems off with where the govenor connects to the carb, I have an identical one I have to pull down tonight I will get a photo of the position to confirm it, but they do have several holes ontop of the carb that linkage can fit in.

Thanks Joe, finding out how it is supposed to work is way better than reinventing the wheel.

It would appear your throttle rods are in the right spot, just to clarify is your throttle cable in the photo tightened down there, that little arm it connects to has a good 20mm travel, it points toward the front wheel when stopped and more or less at the rear wheel when flat out.

I have a question though, on the main bowl nut was there a tiny little O ring half way up? I havent looked far into mine yet but it runs really rich and stutters, it looks like a O ring could belong there. On a positive the float and seat are working perfect, they are the main reason I dont work on tecumseh in general

There were remnants of a black o ring in the small groove of this bowl bolt/jet the carb came up good with a clean but without this it has similar symptoms, low engine speed and seems to be rich loading, checked another motor that had the same model designation but it had an internally different carby, so my advice may be wrong to your engine.

Interesting Joe, i've come across a few of these carbs and many with different jets but never one like that. This might be a job for an exploded parts view. www.partstree.com is handy for parts lists, especially tecumseh's.

Peter, at full load the hole in the throttle lever lines up with the notch in the top plate, (both circled green), in the below picture. The screw i've circled red is your idle speed adjustment. At idle adjust that screw clockwise to increase idle speed. As grumpy said, the screw that is also in the second green circle is your high speed adjustment. Adjust that one at full throttle to increase or decrease your full throttle speed. As always be careful not to have your full load speed more than about 3200rpm. It's a small torx bit but a really small screwdriver will do it if you dont have a torx set.
Let us know how you go when it's done.

Righto:
Grumpy, Your explanation about the throttle cable positioning was spot on after I had a better look. Last night I adjusted the cable accordingly and put the engine back together. I checked my work early this morning against Bigted�s explanation and the throttle lever lined up correctly with the notch on the top carby plate. The lever now moves in a clockwise direction as you indicated.
Joe, My bowl nut/jet is very different to yours. I did however notice sometime very strange with the bowl bolt/ jet when I first unscrewed it from the carby. Inside the jet it had a rubber lining that protruded slightly out of the end of the jet. This was very brittle and when touched it perished. It was only a very minor piece which I thought might be something that sealed the jet against the emulsifier however I could be completely wrong. Perhaps your rubber O Ring was serving a similar principle. I would be interested to know if your bowl bolt/ jet has a similar rubber lining or if any others have an idea that would be great.
Bigted, Thanks for the explanation. As stated above I went and doubled check this morning at the full throttle position lines up exactly with your diagram. So thanks for confirming. I haven�t played with the adjustment screws yet due to my problem below.
My result.
I went to start the engine and it starts for about a second then dies. The speed setting is definitely correct as it sounds much better however, I think the needle and seat might be the issue however I am not sure. I checked the seat and it appeared to be ok however I wasn�t able to get it out without damaging it. I understand there is a special Tecumseh tool and others say a crochet hook does the job. Is there a special trick for setting the needle and the seat to ensure they are positioned and operating correctly? Joe you mentioned checking it so I am curious. The configuration of how the needle and clip attach to the carby float to me seems prone to failure. Would someone have a photo of it set up correctly as I might have it wrong!
I did some more reading about these carby�s last night. They don�t appear to be very popular with many people.
Any suggestions would be appreciated or if you guys need more photos let me know. I hope this turns into a good thread as information on this type of engine is limited!

I'll leave it for Joe and bigted to provide most of the information you need, but I suggest you begin by removing the float bowl, putting a cup underneath the carburetor, and turning on the fuel. See how fast fuel flows past the needle-and-seat and into the cup. If it flows full stream, all is well, but if it only dribbles out, there is an obstruction either in the needle and seat, or upstream in the fuel hose, fuel tap, or fuel tank. All will need to be cleaned out.

You can check the float level approximately, by turning the carburetor upside down and verifying that the float sits horizontally, parallel to the sealing surface where the top of the float bowl sits when it is installed. Note: do not use this method if the carburetor has a spring-loaded needle, as some motorcycle carburetors do for instance, to keep the needle and seat from being damaged by vibration. For those, just turn the carburetor until the float is about 35 degrees past vertical and see whether it is parallel to the sealing surface. That way you aren't putting the whole weight of the float on the needle, so the spring will not be compressed.

None of that tells you how to correctly assemble the needle, retaining clip, and float pivot. However it should tell you whether they are passing fuel properly.

Thanks Grumpy, i know how much you love tecumseh products!!
Pete, do the flow test that grumpy specified and rectify if needed. If it's got good flow and the flow shuts off when you push up on the float, i wouldn't touch it, coz that's probably when you'll damage it. Check the level as above and adjust the tang on the float gently and only a very little at a time. After that i'd suspect that the perished oring you found is the lower one from the emulsion tube. There's 2 on there, 1 at the top of the tube and the lower one you've already found, but at a minimum the lower one needs to be replaced if the top one is still intact. You can pop the tube out with a flat screwdriver through the throat of the carby by pushing down on it firmly, but don't tap or hit it. Once out you can see the extent of the damage to the orings and replace as necessary. With these replaced you should be good to go.
If you get stuck there are some good vids on youtube to help you through.

The float on mine is not adjustable, its plastic, anyway, on a whim I went to the local steel retail today, found a O ring and installed it and my problems were solved....

I found this thread that has a parts list, but not an exploded view of the carby....

https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=23451

Below picture of the carby;

Indeed, I worked out his is a "vantage 35" while mine is a "prisma 37" while visyally they are the same engines, evidently They are a bit different here and there, I did find the relevant documentation for mine in a quick google search

Great thanks for the help.
I did the flow test and the fuel flows nicely and shuts off when you lift the float so I'm happy the needle and seat are working well.
I also checked the float level and it sits horizontal to the bowl so I didn't adjust it.
I took out the emulsion tube and both rings need replacing so I'm going to head to the local shop today to try and get a couple of rings just like joe did. Id get the carby kit from the online store but I only need the rings.
I'll put up some photos tomorrow and let you know how it goes once its back together.

Nothing else I should check before putting it all back together?

Thats about it Pete, put it back together and it should run sweet.
Joe, Pete's is definitely a Prisma37, i suspect you meant that yours is a vantage38.
Pete, out of curiosity, is yours mounted on a masport stinger?

bigted, can you clarify that model information please? I'd been trying to find the engine in the Tecumseh technician's handbook and their general service manual. They mention specific "Europa" models called Vantage, Prisma, Synergy, Synergy "55", Spectra, Futura, Centura, HTL, BVS, BH Series, and Geo Tech Series, without numbers or any information about them except spark plug and quantity of oil. This makes me think they are Italian engines Tecumseh sold under its own brand-name. Web searches find quite a few hits for Vantage 35, but none for Vantage 38.

It would be interesting to know who actually made the engines, and whether there is a workshop manual for them (perhaps under the manufacturer's name).