I sure hope some on can help me? My boys 84 kx 60 is completly falling on its face in the top end as soon as the power band kicks in it goes bllaaaaahhhhhhh spit , sputter, zero power. so far I have replaced the reeds with Boysen power reeds, new filter, new plug, replaced pipe packing, clean carb. my next is piston and rings but I dont have the money right now is there anything I missed?
Help with KX 60 engine?
- Thread starter usnrxdoc
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Moto Squid
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- Jul 22, 2002
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I had the exact thing happen on my old 80 years ago...new top end and it was running like a champ. Do a compression test and that'll tell for sure.
Squid is Spot On here!
Replace that top end and your boy is going to be keeping up with you and doing Wheelies in the yard. Not to mention weeding your garden! That is what the bike needs, granted the piston may be in good shape but the rings deffinatly need to be replaced. Order the top end kit, Pin, piston, and cir-clips.....Big improve ment at a light cost ;)
Replace that top end and your boy is going to be keeping up with you and doing Wheelies in the yard. Not to mention weeding your garden! That is what the bike needs, granted the piston may be in good shape but the rings deffinatly need to be replaced. Order the top end kit, Pin, piston, and cir-clips.....Big improve ment at a light cost ;)
- Thread starter
- #4
Well I put new rings in and checked the piston to cylinder clearance and its in spec , I put it all back together again and now it has great compression but the same damn problem! As soon as it hits the top end dead, dead , dead! Man if anyone in here has any other ideas please let me know before I turn it over to the local shop :flame: and pay 50.00/hr?
What's up Doc?
My son just traded his KX 60 for a 65 and we never had the problem you describe. Years ago (many), I had a Bultaco which did what you described and it drove me crazy... I ultimately found it was a fuel problem... If I remember correctly I believe the float level was off or a jetting problem... I really can't remember exactly but it was carb related.
For what it's worth...
Jeff
(Navy Vet)
My son just traded his KX 60 for a 65 and we never had the problem you describe. Years ago (many), I had a Bultaco which did what you described and it drove me crazy... I ultimately found it was a fuel problem... If I remember correctly I believe the float level was off or a jetting problem... I really can't remember exactly but it was carb related.
For what it's worth...
Jeff
(Navy Vet)
I saw a similar problem at the track one day. A dad and I could not figure out why his son's KX60 would idle great but as soon as the throttle was twisted the bike would sputter and die. Cleaned the carb, air filter, checked the timing. No help. Next time I saw him he said that the coil had a broken mount. So at idle there was a connection to ground, but at high RPM the connection was intermittent. Check your electrical connections. Even though you cleaned the carb did you make sure that the jets, in particular the main, was not plugged? One grain of sand can be bad news. Good luck.
Vytas (AT3) VA-81 USS Saratoga CV-60 1984-88
Vytas (AT3) VA-81 USS Saratoga CV-60 1984-88
Double check the float / fuel level and that there is no water in the fuel. It sounds like a fuel problem but maybe electrical. Dont spend more money, go over the bike checking everything. Is there rust in the stator? I saw a CR80 that a guy stuffed around with for ages at the track. I just plugged in the wiring to the CDI properly and he was roosting. These things are just to drive us mad......
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- #10
ktmdad- (Also, make sure all your vent hoses are not kinked or blocked.) My bottom brass vent on the bowl is cracked inside so I pinched the vent hose off whick stops it from just pouring out. but it ran great like this a few weeks ago, What will it do if the vent hose is blocked? How do you test a stator?
Jasle
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- Nov 27, 2001
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our stator went out a while back. when it did the bike would start and idle fine. but when reved it would start sputtering on the top end and sometimes while WFO the bike would change rpm with no throttle change. Replaced the stator and it was fine. Also it ohmed out fine when not under a load. The only reason I found it was because someone had a spare stator for me to try and I was out of options.
DEANSFASTWAY
LIFETIME SPONSOR
- May 16, 2002
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Clean out the petrcock and check the floats in the carb , I can remember that on KX 60s it always looked like the carb was casted lopsided , the float would actually look like it was riding at an anglewith the carb upside down . If the float is too low the motor will lean out on top and could seize up or too high it will be too rich and not rev out clean . Maybe replacing the float valve would be a good idea on a bike a few years old. Could be the Ign but its hard to check unless you can swap a cdi box from a pals bike. Water can be very decieving also , and usually only messes the bike up on top due to it laying on the bottom of the float bowl . I have seen little 60s suck in the base gaskets espescially paper ones. Maybe the trans vent line is clogged up or pinched and the trans builds up pressure on high Rs and leaks a little oil into the crank area fouling out the top . Is the plug clean or dirty? Good luck
DEANSFASTWAY
LIFETIME SPONSOR
- May 16, 2002
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Could the gas tank vent or cap be bad and not letting any air into the tank when the fuel goes down? I hsave seen this before where the steering head is packed with grease and it gets into the hose and blocks it off . On Newer streetbikes they have a rollover valve which wont let gas out if the bike is on its side or in a crash . On some streetbikes they went bad and the bikes ran bad and the metal fuel tanks actually caved in or imploded and had to be replaced . Just a thought .. DEAN
