78 Cyclone

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kuku
Posts: 22
Joined: Tue Aug 23, 2011 8:58 pm
Location: IL

78 Cyclone

Post by kuku »

Ok guys need some help with my 78 cyclone. It idles fine but I cant get it to clean out and it loads up the lower end. Its like its running real rich. I am going to change the crankcase seal behind the clutch to rule that out, but any other ideas? You think its the needle and seat?
Norton
Posts: 289
Joined: Thu Nov 01, 2007 12:00 am
Real Name: Keith Bylin
Location: NE North Dakota

Re: 78 Cyclone

Post by Norton »

hello kuku,
A friend of mine has the exact sled (440)with the same issue. New crankcase seals and all! So I will be watching the replies. He did replace the needle and seat but I am not sure he got the correct one from the local AC dealer. They are sized and made of different materials. Thing is a pig on fuel too. Maybe 45 miles to a tankful. Quick and dirty way to test the PTO seal is to spray starting fluid at the seal and listen if the engine changes RPM. Please be careful spraying starting fluid around a running motor!! Many parts are rotating and some are hot!!! Have you checked the timing?? Don't think my friend has his Cyclone.

keith
kuku
Posts: 22
Joined: Tue Aug 23, 2011 8:58 pm
Location: IL

Re: 78 Cyclone

Post by kuku »

Ok,
I will start with the seals, and I did check the timing and it is right on.
I am also wondering what symptoms a CDI box going bad does?
Thanks
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HoosierDeereMan
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Real Name: Troy Miley
Location: Oakland City, IN

Re: 78 Cyclone

Post by HoosierDeereMan »

What is your idle RPM? Most guys will set the idle 150 to 200 RPM under clutch engagement. If the idle RPM is too low and you blip the throttle the sled will stumble all over itself and bog down.

Troy
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harleysportster
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Real Name: Pat Scott
Location: Southeast Pa.

Re: 78 Cyclone

Post by harleysportster »

kuku wrote:Ok,
I will start with the seals, and I did check the timing and it is right on.
I am also wondering what symptoms a CDI box going bad does?
Thanks
If you do not know the history of the the engine, I would replace the crank seals first thing. Also, I would check the cdi system, it sounds like either a weak spark or loss of one cylinder.
See the topic in the FAQ section.
http://www.jdsleds.com/community/viewto ... f=5&t=2473
'76 440 cyclone
'76 440 liquifire
'78 440 Cyclone
'75 JDX8 (sold to a member here)
'78 Liquifire(CrossCountry Clone)
'80 Liquifire(sold)
air mechanic
Posts: 72
Joined: Tue Feb 19, 2013 10:32 am
Real Name: Les
Location: Marquette

Re: 78 Cyclone

Post by air mechanic »

Having the same issue with my 78 Liquifire. Mostly the MAG side cylinder,rebuilt her last year. Fuel pump pulse line is on the PTO side so I have semi ruled that out. Have had carbs apart,new needle valves and seats,adjusted the needle on the slides,got her running better but not right yet. My next thing is the inrichment valve,got a new one only $5,thinking the old one may not be sealing completely. Having a simler issue with my 79 El Tigre,got to love 30 plus year old carbs.
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