Member Contributer RC36B Posted September 11, 2019 Member Contributer Share Posted September 11, 2019 I have a problem that have happened 2-3 times over the last year - sudden partial loss of power during accelleration. I short while ago I found a float valve seat that was wrong setting the float 1-2 mm to low. After a test assembly and a short ride I experienced a lean condition on de-acc which simply could not be the case. I took the suspect carb apart again (the one with the wrong location of the seat). When I removed the float valve, I realised the valve seat had moved and was now loose. A little shaking and the whole damn valve seat fell into my hand! That was a new one! Those are not removable so not quite sure how this seat is secured. Anyone any ideas? What is the best way to secure it? Link to comment Share on other sites More sharing options...
Member Contributer airwalk Posted September 12, 2019 Member Contributer Share Posted September 12, 2019 Replace carb or fiddle with slightly larger cross sectioned o rings on seat, looks from pic like it has one around it. or might be able to “peen” into body with a punch mark (dimple) in 3 or 4 places on edge of hole it sits in. Best is replacing carb tho Link to comment Share on other sites More sharing options...
squirrelman Posted September 12, 2019 Share Posted September 12, 2019 try fatter O-ring, but don't try punching the metal as it's brittle and will crack b4 deforming. Link to comment Share on other sites More sharing options...
Member Contributer RC36B Posted September 12, 2019 Author Member Contributer Share Posted September 12, 2019 2 hours ago, squirrelman said: try fatter O-ring, but don't try punching the metal as it's brittle and will crack b4 deforming. Squirrelman, is the o-ring the only thing holding that seat in place? I would have thought they were pressed into the body... Link to comment Share on other sites More sharing options...
Member Contributer RC36B Posted September 12, 2019 Author Member Contributer Share Posted September 12, 2019 I have temporary fixed the seat with Loctite 648 - hope it will be ok for now... in a month or so it is winter and a more permanent solution (new carb) can be found. I'm pretty sure this fixes the random problem I have had a few times (partial loss of power) - time will show. But I can now conclude that the seat must have been a factor for quite a while; power delivery is so different now with the seat fixed in position! In the clear light of things now I can only punch myself for another missed sign of this problem. That cylinder once had a spark plug that was a little soiled. After cleaning plug and connectors to the coils, the plug appeared to stay clean and nice - case closed... I thought. Now I realise that the seat could have been the problem... moving out of place and making mixture more rich when I noticed a soiled plug, then moving back into position when plug was checked some time later. I also have had a "feeling" that something was odd about the mixture on the pilot screw. But every time I checked the pilot screw by going a little in and out to get the rpm drop, it checked out ok. The other day I got a pop from the exhaust - right then I knew something was totally not right... no more "feeling", though the pilot screw, I knew, was not lean, all jets absolutely clean, the air cut off valve new (and bench tested before installation), fuel stainer and filter new etc. Now with the whole picture it is easy to see it all pointed to fuel delivery / wrong fuel level in carb. I did notice the seat gave a wrong level but as it was firm in place I thought it was a production error that was never corrected. Unfortunately, I misunderstood that completely and it was not until the seat drop out that I picked up what was going on. So, go ahead and laugh of my stupidity 🙂 And now you don't have to make the same mistake 🙂 Link to comment Share on other sites More sharing options...
squirrelman Posted September 12, 2019 Share Posted September 12, 2019 14 hours ago, RC36B said: Squirrelman, is the o-ring the only thing holding that seat in place? I would have thought they were pressed into the body... sorry, but i don't know. i would have thought the same, pressed in. on some carbs from other hondas and yamahas, the seat has a similar O-ring but also a screw and tab securing the sear in place, unlike on your RC36. i believe your report is the FIRST on this topic. Link to comment Share on other sites More sharing options...
CharlieFoxtrot Posted November 15, 2019 Share Posted November 15, 2019 The loctite is probably a permanent fix, if you want it to be. Link to comment Share on other sites More sharing options...
Member Contributer RC36B Posted November 16, 2019 Author Member Contributer Share Posted November 16, 2019 13 hours ago, CharlieFoxtrot said: The loctite is probably a permanent fix, if you want it to be. Winter is coming up so time to take a better look at that carb. If seat is secure and the loctite seal the seat I will leave it is as is. Link to comment Share on other sites More sharing options...
Member Contributer RC36B Posted January 5, 2020 Author Member Contributer Share Posted January 5, 2020 I took this carburettor apart again to inspect the the seat secured with Loctite 648. I did call this a temporary fix but it is like "welded". I have also tested for leaks - and found it to be leak free. So, I will leave it as is. So if you ever have odd signs of exhaust pops or extreme rich mixtures for one cylinder now and then, maybe a float seat is loose. Link to comment Share on other sites More sharing options...
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