OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines Victa 2 Stroke wont rev up.

I have rebuilt a number of victa 2 strokes however I have one that is giving me trouble. Its a standard power torque engine (The new style where the cooling fins are spaced further apart).
Upon getting the mower the guy said it just stopped and I didn�t get much more information at the time.
I completed the following:
Cleaned the carb and added all new o rings (inc manifold o rings)
Replaced the crankcase o ring
Took the head off and removed the piston and rings. Gave them a good clean and re-installed everything as it looked good. Included a new head gasket.
Re-gapped the magneto and checked for spark which was reasonable.
Went to start the mower and NO go.
I re-checked the carb and its was all good. Thought it might be a blocked exhaust. I replaced the exhaust and the engine started however it just wont rev up.
I changed the large carby spring to a firmer unit to try and increase the revs but no go.
Subsequently checked the exhaust port and it was all good.
Checked the carby float (no leaks) . The jet has been cleaned thoroughly. I must be missing something����������
Can a leaking lower crankcase seal cause these problems?

I just removed the exhaust again and the exhaust was covered with oil. I have the plain face jet (no rings) as per the victa manual.

Fuel is mixed as always at 25/1.

Sounds like carby to me ,I would try a carby off a known good running power torque engine that way you can at least rule out that side of things,id also be looking at the throttle cable that little ball on the end can be a bugger at times to seat home.....Sounds like you know your stuff and are doing the right thing eliminating one thing at a time....Good luck not that you need it. you will have it going in no time...cheers Chris

Hi Pete, check the air filter and try a leaner jet(1 or 2 ring). The oily muffler suggest that your air/fuel may be too rich and obviously not burning the oil out of the fuel mix, although this is also common when they're not revving at the desired RPM.

Thanks Chris and Theo,
Well��
I changed the carby shell thinking that might be the problem however I didn�t have another working power torque around to try and known one but I did have a wrecked one. I swapped the carby shells and the problem was still the same. The engine would idle ok, albeit a little rich and then when you move it to full speed it only had a very light change. The engine was still running super rich.
Option Two (tried the one ring jet)
Mower started on the first pull again and it fired right up with good speed however the speed setting was everywhere. It was revving ok at the start but then it started to rev up and down without touching the throttle controller.
The mower had a plain face jet when it arrived and the like I said earlier the guy was adamant it just stopped. The previous owner did say it always went without a problem.
I think I am down to the last option (that being to tear out the crank bearings and replace them. They were slightly noisy when the engine actually fired up.
Any suggestions would be appreciated.

I'm still back at the carby on this one Jaffa. The bearings wont affect revving performance unless they are binding, but then you'd know that by just pulling the starter cord. If the seal is shot in the lower bearing it will cause overrevving issues just like a bad diaphragm or a starter seal. You've really got to get a complete working carby and keep it as a test unit for situations like this.
Try some of the following, not necessarily in any order:
Is the poppet valve set to "C"?
How's the air filter?
Have a beer and think about it some more.
Try it without a muffler(wake the neighbours), but watch out for the shooting flames.
Try a known good working spark plug.
Have another beer and pray to the mower gods.
Does it over rev with the vacuum line to the diaphragm disconnected?/ If yes, try a diaphragm cap with the brass restictor in it.

Thanks for the idea�s Theo.
The mower is now running like a charm.
The problem ended up being a piece of foam pre-filter stuck in the air intake which was inturn restricting the amount of air the engine could suck in through the air filter. I didn�t see it initially. I just took the old air filter out and gave it a blast with the compressor to get rid of all the debris inside. Only when I looked down the snorkel with a torch did I see the foam pre-filter broken into a couple of pieces and just about covering 80% of the air intake (hence why it was running so rich).
With my multipurpose crochet hook this piece of foam was easily removed. The mower fired right up and just about smoked out the paddock I was testing in however after about 2-3 minutes it cleared right up and continued to run perfectly.
For my own curiosity and installed the original muffler and the engine wouldn�t start (thus confirming the blocked muffler)
So I am assuming the previous owner continued to mow with the air intake badly blocked which caused the engine to run rich until it blocked the exhaust completely and wouldn�t start. So all the [Censored] thing really needed was a new exhaust and that stupid piece of foam unjammed from the air intake!
Lesson learnt�.. always check the [Censored] air intake with a torch and don�t just blast the compressor down it.
Hope this is of use to some others!

All good Pete, i'm glad it all worked out. Just a note though, dont blast compressed air down the snorkel, all that will achieve is pushing dust and crap that was happily sitting against the inner wall of the snorkel down into your carby, thus ultimately causing you more problems.