KymcoForum.com
Scooters - 50cc => Agility 50 => Topic started by: Kimcofan on March 06, 2010, 10:58:43 PM
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Well I got my scoot back and after letting them know they should have called me and told me it was going to be more time, they agreed to charge me an hour, but it's not like it helped any the scoot still isnt working it starts but there is a whole new set of problems now. There is a tapping in the motor and no power what so ever I am not taking it back to the shop. Anyone have any suggestions, I think maybe the valves arent set correctly and it may be tapping on the valves even though they said they were set correctly. I still have no idea about the power issue I did not try to ride it but when i gave it throttle the bike did not move at all tire spun when off the ground but any weight no go. They also told me compression was good. I have a 86 jet in it i believe, could that be the problem since I put the 72 cc kit on , I dont feel like that would effect the power that much though. Open to suggestions. :-\
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The tapping could be caused by the stroke being slightly too long. The valves may be set correctly, but the head is not tall enough. Maybe you need a thicker cylinder gasket. I'm not exactly sure how the 4 stroke kits come, but on my 2T I had to double up on the base gasket and head gasket to get the right clearance. As for the jet, when you give it throttle does it want to die? The 86 jet could very well be causing your loss of power. Especially if it idles but doesn't rev up.
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It revs up the wheel moves when lifted off the ground but when on the ground revs but does not move as far as the head there is a new block and head on it the motor was rebuilt I may try doubling up the gasket but I think I might try to raise the valves first to see if that is the problem before taking apart, I hope I didnt bend the valves if they are set wrong. Didnt run scoot but for half a min or so
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I really don't know what else to suggest! I just don't have a whole lot of experience with 4 strokes. They are some different animals! I'll keep thinking about it and post back if I think of anything profound. :-\
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Yeah, this has been nothing but a pain in my ass. I just want it to be running correctly.
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I've been watching this thread off and on and now I'm feeling real bad about this bad luck you're having. >:( I went back and read the whole story of the conversion from when you started. Wish I knew what to tell you. Only think that came to mind was this thread where the fellow had similar problems and it eventually worked out ok. The bottom of the 1st page is where he finally gets it together and hears noise. Kymco 250cc - Can't Start it « 1 2 » (http://KymcoForum.com > General > Technical | How To > Kymco 250cc - Can't Start it « 1 2 ») I know it's a long shot but hoping it might have some similarity to your situation. Good luck to you. Well, looks like the link doesn't work. Look it up under the Technical forum here. It's on the 3 page of that.
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Can you feel any play in the wrist pin? Turn the engine foward, and back by hand. Loosen the head and see if the tapping goes away. If it does pull the head, invert it w/ the valves closed, and pour a small amount of fuel in it to see if the valves are seating. I don't understand how they could give it back w/out explaining any problems. Try those couple things, and post back
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I have not had a chance to work on my scoot yet, but I did have some questions. If the valves are set too low could that cause my not having power issue? Also I got some variator weights with the 72cc kit which didnt have the actual weight on them, I have a feeling they probably weigh more than my old ones, could this be a cause of my power problem? When I put the cylinder on there was no play in the pins, everything was assembled to the manual. I really have a feeling the shop adjusted my valves too low, I hope running it for the 20 seconds didnt bend a valve. I will be working on it on Saturday so I will keep you updated, any input you guys have is helpful!
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I'm thinking if you changed to heavier rollers when you did the kit that may be the cause of your loss of power. That would explain why when the scoot is on the stand the rear wheel turns, but has now power on the ground. Really just a thought, because it does kinda sound like a cvt issue the way it revs with no load, but has no go! Try putting your stock rollers back in there and see what happens. I have a bunch of different sets of rollers, all of which aren't labeled! I have a gram scale I throw them on. I'm no expert with 4 strokes so I can't really offer any advice on the valves. I would be raising hell with the shop you took it to if they are not right though! Especially if any damage resulted from their incompetence! You may want to find a good mechanic to get a second opinion! Definitely check the rollers though!
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I'll change the rollers and adjust the valves. My friend seems to think the rollers wouldnt cause that much loss of power he said that even if the rollers are too heavy that the scoot should at least be able to pull its own weight any thoughts on that?
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Not sure! I know that the wrong weight rollers will make a tremendous difference! Only one way to find out!
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Yeah! there is something else wrong. Have you looked at any of the utube vids. for the roller swap? It's a straight foward easy thing to do. you can pull the cvt cover, inspect it all, And if you are sure your valves are not hitting, start the scoot, and see what is happening inside the cvt. If you had anvils inside the var. the scoot would want to roll off the stand. you seem to have the opposite.
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I swapped the rollers myself very easy process, I will check out the transmission, but I really have a feeling all of these problems stem from the valves, I am just brainstorming on other possibilities in case it isnt the cause of the problems. Everything in the motor is brand new, the electrical system works, and the scoot starts. So the only things I can think that are causing tapping and loss of power would be fuel problem, valves, cylinder, and transmission. Considering the block, crank, piston, and head are all brand new ordered specifically for this scoot I doubt it has anything to do with the parts, it has to do with settings.
Because I put the 72cc kit on the scoot, would my valve adjustment be different than factory settings?
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Have you tried contacting the shop? I get the impression they may not tell you much but any clue from them? I agree it may be timing related but don't understand how they would just drop it on you!
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I dont think the shop will be any help. They are mad at me for only paying for an hour when they tried to charge me for double for timing and valve adjustment when the scoot was already apart for them. I also told them before they did the work I was only able to pay for an hour and they agreed in writing to that. So pretty much i would have paid 2 times as much for a scoot that still didnt work. Even if i paid for two hours and brought it back there telling them it still wasnt working they would probably try to charge me even more because thats how they seem to operate a business.
I wish the entire conversation with the shop was recorded because they were said "We will only work on it for an hour if more time is needed we will call you, we do not operate like regular shops we actually do what we say"
If you want it done right do it yourself!
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That's how I look at everything! I figure if someone else can do it so can I, and If they say it can't be done I will be the first to do it! It may be something simple like a missing base gasket, or low deck hight, but I think the shop would have spotted that. Couldn't hurt to double check tho.
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I am going to check and double check everything and then i am going to check again...until i know whats wrong then when i gain the knowledge of everything I know about this beast i will spread it like wildfire to everyone that is willing to learn so maybe these worthless ripoff shops get less business!!!
Oh yeah back to my question: b/c i installed the big bore kit would my valve adjustment be different than stock?
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I am going to check and double check everything and then i am going to check again...until i know whats wrong then when i gain the knowledge of everything I know about this beast i will spread it like wildfire to everyone that is willing to learn so maybe these worthless ripoff shops get less business!!!
Oh yeah back to my question: b/c i installed the big bore kit would my valve adjustment be different than stock?
I like that philosophy!!! That's what I'm all about! I really wish I could help you out with this one. I just haven't worked on enough 4 strokes to have the knowledge. I'm learning new things from your experience everyday! So, thanks! I can't wait till you figure it out, as I will have learned something new as well! ;D
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Yeah, I love this forum it is a huge help on a lot of troubleshooting. Hey dont worry I bought a 2 stroke A50 off a buddy for dirt cheap that wasnt running, its missing the front plastics but seems like it has all the motor components, not sure about the electrical schematics though, will be my next project im sure you can help with that project. I believe its a early 2000 model and i got it for like 40 bucks so i couldnt beat the price.
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Congrats on the STEAL kymcofan! I never asked if the kit had new valves/head/cam w/ it
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the kit had new block, head, piston w it
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Same head? The piston dome! can you compare your old one to the new one? Put a straight edge across the old dome, and measure to the edge. aNOTHER FACTOR IS THE COMBUSTION CHAMBER on your head. It may be affecting the travel of your new piston. (most likely) You will have to pull the jug to measure the new piston but I have NEVER seen a larger jug work w/ a smaller head. That's your tapping. The piston is hitting the outer edge of the head, and not the valves. You can fix that by fitting 1-2 more base gaskets under the jug, but you will wind up w/ a HY-BRED combustion chamber that may burn pistons faster than rings. The fix is to go back to the supplier of the jug, and get the MATCHING head. Ask if your cam/valves/springs/timing chain will fit, or if they all need replacement. Sorry it took soooo long to figure, but I am at home, and you are there. I'm sure this is the problem.
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Didn't he say he got a new head with the kit? If so, did the now head come with the valves, or did you have to switch all the "head guts" over? Could it be that your old valves don't fit properly in the new head? It would seem that a larger displacement engine would require proportionately larger valves as well. Idk, just throwing some ideas out there!