dsb2014 Posted August 15, 2014 Share Posted August 15, 2014 I've put new piston kit On as my old 1 shot a hole bang in the middle. I got it to start but it wouldn't go faster than 15mph if that I'm wanting some advice on so may be causes. The bore looked ok to me nothing jumped out a mate says it could need a rebore but I don't know as he hadn't seen the barrel Off the bike. I think I'm asking for a second opinion. Please please help its a nightmare!!!!! Thanks so very much any ideas/advice I'm grateful Link to comment Share on other sites More sharing options...
blackhat250 Posted August 15, 2014 Share Posted August 15, 2014 How does it start, ? and 15 mph .is that in 1st gear,,, i think the compression is low,, Link to comment Share on other sites More sharing options...
Moderator Airhead Posted August 15, 2014 Moderator Share Posted August 15, 2014 dunno fook all about a majester? is this a majesty scooter thing, does it have a carb...a choke etc ? Link to comment Share on other sites More sharing options...
dsb2014 Posted August 16, 2014 Author Share Posted August 16, 2014 Yeah it's a scooter four stroke. It takes a few attempts on the electric start to get going. Hmm compression low seems like the bore could be a problem???? Thanks guys for taking time to reply always appreciated Link to comment Share on other sites More sharing options...
dsb2014 Posted August 16, 2014 Author Share Posted August 16, 2014 Sorry airhead yeah mate it has carb and choke Link to comment Share on other sites More sharing options...
AndrewElvisFan Posted August 16, 2014 Share Posted August 16, 2014 I'm not familiar with the Majesty, but when I had a Piaggio scooter I had a similar problem. There was a simple screw below the seat (just above the carb) which needed adjusting. I know it was a carb setting which affected the mid and high revs. Mine was only a 50cc. If there isn't this screw, have you had the carb apart - could be one of the jets is blocked?? Link to comment Share on other sites More sharing options...
dsb2014 Posted August 16, 2014 Author Share Posted August 16, 2014 No I've not had it apart yet but u suppose I could rule it out. Link to comment Share on other sites More sharing options...
AndrewElvisFan Posted August 16, 2014 Share Posted August 16, 2014 I'm no mechanic so only guessing. Does she rev up when on the stand? Link to comment Share on other sites More sharing options...
dsb2014 Posted August 16, 2014 Author Share Posted August 16, 2014 Yeah but really really limited Link to comment Share on other sites More sharing options...
Moderator Airhead Posted August 16, 2014 Moderator Share Posted August 16, 2014 burning a hole in the piston can be ignition timing too advanced, I'd suggest checking the timing and stripping/cleaning the carb and it's jets, you can buy aerosol carb cleaner sprays Link to comment Share on other sites More sharing options...
dsb2014 Posted August 17, 2014 Author Share Posted August 17, 2014 Im thinking it's the choke. Is there awaybti test it before I purchase a new Link to comment Share on other sites More sharing options...
dsb2014 Posted August 18, 2014 Author Share Posted August 18, 2014 Ok I have git it running but wen I put the throttle back it bogs out and cuts out I only have to put it bk a little bit Link to comment Share on other sites More sharing options...
blackhat250 Posted August 18, 2014 Share Posted August 18, 2014 Ok , how does it start from cold ? and is it bogging after choke is off.? Link to comment Share on other sites More sharing options...
dsb2014 Posted August 19, 2014 Author Share Posted August 19, 2014 It starts ok from cold and bogs out from the Get go Link to comment Share on other sites More sharing options...
wild foamy Posted August 19, 2014 Share Posted August 19, 2014 Lean mix would be my guess. Would explain the cutting out under throttle input and the holey piston. Link to comment Share on other sites More sharing options...
dsb2014 Posted August 19, 2014 Author Share Posted August 19, 2014 I've never messed with suction carbs before so a lean mix to me in 1 if theses means nothing lol. How would I adjust this?? Link to comment Share on other sites More sharing options...
slice Posted August 19, 2014 Share Posted August 19, 2014 Look in your manual for the carb settings and turn the fuel mixture up or the air mix down, whichever is set wrong, best bet is to take it back to factory settings and go from there. Usually the factory settings are ok when new but stuff wears out and needs adjustment, usually a quarter turn in or out can be a major benefit but DON'T do big changes from the original setting as that can cause problems as well. Link to comment Share on other sites More sharing options...
Noise Posted August 19, 2014 Share Posted August 19, 2014 Take out your spark plug, if its white then you are getting too much air and not enough fuel, this in time will course piston damage. If the plug is sooty blck then you are getting too much fuel and not enough air, again over time will course piston damage. When a engine bogs down under load (throttle) normally points to not enough air (but also not enogh fuel) hence the spark plug check. As you have changed the piston and have had to remove the barrels to do said task you have removed the carb from the barrel?? if your a good lad and done this have you tightened up the inlet rubber that clamps the carb to the barrel? if you haven't then you will be drawing in extra air through this gap and running weak. Make sure that the inlet rubber is done up tight. If that fails or you have done the rubber up tight then dose the bike rev when the choke is still on? if it does then we need to suss out if your choke adds more fuel or more air. Link to comment Share on other sites More sharing options...
dsb2014 Posted August 19, 2014 Author Share Posted August 19, 2014 Can andvhiwvdo I adjust the fuel/air mix?? Link to comment Share on other sites More sharing options...
dsb2014 Posted August 19, 2014 Author Share Posted August 19, 2014 Sorry how can I adjust the mix On a suction. Carb Link to comment Share on other sites More sharing options...
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