Mantis Tiller Help!!

OldDiyer

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Hi all, so I purchased this Mantis as a no run unit but had faith that I could put it back to working condition. Over winter I did a clean up and ordered a few replacement covers etc. Also the carb looked pretty bad, dirty primer bulb cracked and overall it didn't look like it had been running for a while. I ordered a new carb with lines, filters, plug etc. So got at this today to see how it was going to run had a few issues. Got it to run on its own finally and it does run and does speed up fine didn't use it in any dirt yet but seems to have a problem that I can't seem to figure out. It will now start fine and I let it warm up good but after that when I give it higher Rpm I am getting like oil spatter coming from exhaust at first I thought it was just running rich but that doesn't seem to be the problem because if I lean out the carb it still seems to be doing this. If I had 40-1 instead of 50-1 would or could that be my problem?? It doesn't seem to be smoking all that much but still concerned that I am really missing something. Your help would be appreciated As many I ordered the whole carb setup because all the stuff I wanted to replace came in the kit. So if you have any ideas what I could or should do please let me know.Thanks
 

sgkent

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I think they use 50:1. Mine did. How old is the fuel?
 

OldDiyer

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Sorry life got in the way so I didn't reply right away, yes the fuel is fresh as it was just mixed the beginning of summer for other 2 cycles but I did use the 40-1 mix in the Mantis but you are correct it is 50-1. Do you think that could be the issue? Being has how the chain saws and hedge trimmer are using the 40-1 I didn't think it would be bad for the Mantis what do you think? Could that little bit of extra oil do the spitting of oil ? Like I said it dosen't seem to be smoking as it runs.
 

StarTech

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I haven't worried about mix ratios in the last ten years since I switch to a multi-mix oil that is can be used in anything that is 16:1 to 50:1. Sure cut down on the number of containers of fuel mix going bad.

Now on the old tiller it might old oil in the crankcase working loose and being discharged.
 

OldDiyer

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StarTech I was just reading some articles on oil mixing and as I was reading, I was thinking the same possible thing as I do not know when or how long ago this Mantis was used or how it got put away. I am just stumped as to how I am getting the oil spitting but not alot of excess smoking but who knows whats in the crankcase as you mentioned.
 

ILENGINE

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Depending on how long this thing has been setting. Some of the early synthetic 2 stroke oils were not exactly real flammable. So it was common with some brands of oil to basically slobber out the muffer. Probably had over 100 complaints with oil dripping from the muffler on Poulan featherlite trimmers.
 

OldDiyer

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Heres an update, not really fully fixed yet. So I ran this thing for maybe 10mins or so and it started stalling than remembering a post on net by someone that if the tank isn't venting can cause this so I took the small vent apart nd removed the rubber one way valve no more stalling or rich running but after running a bit longer and raising rpm it is still spitting the oil. Now I have dumped the gas from the tank and bought new full synthinic oil and am going to try that as well. I also found that sometimes these things need a bit hotter plug found this after doing more reading so I did pickup a new NGK plug for this Mantis. I am adding a picture of the oil it is a bit dried up but it will give you an idea of what I am trying to cure. One last thing I did use it to till some ground and it does work OK but still not 100%. If you have any other ideas I'm still here. Thanks for the help as at least ideas are getting me closer to a win. IMG_20230528_105654.jpg
 

sgkent

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I don't know. I had one that did not run well when I bought it, replaced the carb with a genuine replacement and not a clone, it ran fine after that. I also have a hedge trimmer that was acting goofy. Replaced the carb with a genuine one it ran well then would die about 1/2 tank. While replacing the cap, the hose inside the tank had rotted and the fuel filter and pickup had fallen off. Replaced them and all is well. My guess is that something is still not right with your fuel delivery. Drilling holes in a cap, trying alternate plugs etc., tells me that we aren't subscribing to best practices, and sometimes just throwing things at a problem like this will come back later as another problem. When you replaced the carb did you replace fuel lines, the filter, all the gaskets using genuine or equal parts?
 

OldDiyer

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I'm back with another up date. First off sgkent I get where you are coming from but if you check the first post, I put in new carb,all base gaskets all 3 fuel lines filter, breather air filter air filter cover because mine was missing. At this point it is up and running pretty well after (my last post) I did change out the plug again with a bit hotter NGK plug and new gas mix but this time I am using full synthinic oil at 50-1. Now it is running really good but still showing a bit of oil but now I am thinking this is going to be the way it is as my chain saw also has a little oil spray as well so now I am happy with the unit. Like I had also said in the other post I read on a internet post somewhere that there was some problems with the breather and some people install some type of breather hole to the gas cap but my unit has an external breather so all I did was pull out the rubber little valve and that took care of the venting and now it is not building pressure in the tank. The little filter or breather is pushed up under the upper plastic housing witch is above the gas tank so no fuel is leaking from it even when tilling up any dirt or weeds.
At this point I would like to again Thank you all for the replies at least it gave me a direction after the repairs I did, I am not a person that would be just putting new parts at something to see if it works or not but when I get something like this I replace all the normal problem parts as needed to get it up and right. Thanks Again
 
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