OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Victa Two Stroke Engines victa full crank reving hard

Hi Guys, I recently aquired an old Victa Full Crank 2 Stroke which I got going after fitting a new needle and carby cap. Iv given the engine a standard once over: New inlet o Ring Regapped magneto All carby seals replaced along with needle. The engine starts quite easily however it is reving really hard compared to the other full cranks I have worked on. The blade plate was clean so I suspect the bottom seal is ok however in this case I think it might be the top seal which is contributing to the over reving problem. Could this be the case? I assume just checking the seal with a little petrol would be best. Any tricks when I replaced the seal? Will it just slide in? Would appreciate any tips on getting it out as well please.

Before attempting to replace the top seal I would suggest making sure the carb diaphragm is sealed properly, simply suck and blowo n the vacuum line on the back cover gently, there should be a little movement but no continuous air flow.

Already double checked the diaphram and it was in good knick. Completed the test as I do on all black plastic carbs. Possibility of the seal? Thanks

Peter,

Before you replace the top seal just place some fuel around it and turn the crankshaft to see if you get any bubbles and if you do you have no option but to replace it.

Will do Bruce. Is a special tool required for the top seal? I have also read the need for some gasket goo on top of the seal when replacing it.

Tried starting after testing it this afternoon and no go so checked the top seal and it was gone with a small spot cracked off. The seal is out now. I have the new seal. Is it just a case of taping the new seal in evenly. I have heard that you need to rub some gasket goo on top after it's been installed. Is that it? Thank you

I'd lube the seal with some oil, never heard of putting any goo as such on it.

Installed the new seal yesterday afternoon and thought I'd check the bottom seal while I had the engine off. The seal wasn't letting any petrol through so left it alone.
Installed the engine back onto the freshly painted base to test it.
It started first pull.......... It idles really nice and smooth. However the damm thing is still revving hard at full speed.. I mowed the lawm with it but it's still not right compared to my other full crank engines. The throttle cable is adjusted properly.
All the seals on the carby and inlet are new. New exhaust gasket as well.
I'm out of ideas however I read a post about washers behind the cam lifter in the carby because they wear.
This thing although acquired for free is giving me the sh@ts. It's had some love and not returning the favor!!!!

Also installed a near brand new diaphragm and still no change

Peter,

Did you replace the 'O' ring behind the carby mount block?

Hi Guys,
I have attached a photo of the old girl just about finsished and ready for a new home.

However the damm thing is still reving really hard. I replaced the seal behind the inlet manifold however no change.

I have good throttle response from idle to full speed however the damm thing when at full throttle sounds like it is going to take off!!!!!!!!!!!!

I have tripple checked the governer and it isnt blocked, the diaphram is sealing as it should and all other seals on the carby have been done.


I checked the piston and it only has a little scoring on the exhaust side however it is just about unmarked on the inlet side which tells me the internals have been looked after with a good fuel mix. The bearings are nice and quiet with very limited movement. The rings also look good.

Any suggestions would be appreciated.

Thanks

Peter

Any thoughts on this one. It needs to go off to a family members home that needs a mower.
Thanks

Hi Peter, You can play with the revs by turning the vacuum pickup on the cowl while the mower is running full throttle. Leave the vacuum line connected and push the black plastic part inwards and twist at the same time. This will adjust the pickup relative to the flywheel and ultimately alter the vacuum and hence the RPMs.Try this first as i'm almost certain this will alter your revs BUT if it doesnt help try another carby off a mower that you know doesnt rev its head off. You might find that the different governor spring plays a big part in the way it revs. Victa make different colored springs for different rev ranges, but, with time the color wears off and they all look the same, so swapping a few around sometimes help, although this is mainly on the power torques as they have no adjustment on the vacuum pickup.
Let us know how you go.

Bigted you were spot on. One turn and it was revving beautiful. I was amazed how much difference it made. Low idle is perfect and smooth. Full throttle to me is perfect and smooth and starts first pull. Personally I like the full cranks better than the power torques.
The old girl is ready for it's new home and saved from the scrap pile. I
I appreciate your help greatly. This forum really is a great place to learn.
Peter

No problem Peter, and yes the full cranks are far more superior than the power torques. They were designed to do what mowers should do, make lots of noise and cut grass.lol

That base looks great, I have one full craqnk the same stashed beside the house for when the lawn is too dry to use the scott bonnar, noisy thing it is, great for a saturday morning when your neigbours have been partying all night.

Anyhow good job on getting it sorted, I will now close this thread, if anyne needs it reopened feel free to PM a moderator.