1983 CR480 "smoker"

[83CR480]

I have been restoring a 1983 CR480 for the past few months. The problem I am encountering is loss of power and smoking. I use Amsoil Sabre Synthetic at 75:1. The bike puffs out smoke like a factory! It also has no power...like it is bogging down. I completely cleaned the carb. then backed out the air screw to 3 turns out with no change. I pulled the needle (28G) and moved the clip all the way to the top to lean it out with only marginal results. After you start it (quite easy...3 kicks?) it idles fine and seems to run and rev up ok. Once you get on it and ride it...no power. Afterward I checked the plug and it is wet! Someone stated that it could be the crank seals??? I am not the most savy / expierenced mechanic, but am committed to getting this bike going........I cannot afford to pay someone to do it for me. Any help would be much appreciated

[CRazy96]

Fill your oil up to where it should be...check your oil level after riding it for a bit... If it's low then it's probably your crank seal... Just had the same situation with my 96 cr 250... If a bike suddenly starts running like crap obviously something went wrong or changed... I'm not sure why people insist on re-jetting... But look at the obvious things first... are there any restrictions with airflow (dirty air cleaner plugged up exhaust), is your carb dirty (probably not since you've just cleaned it) is your fuel mixed correctly?. When my oil seal was bad the plug was wet with thick oil not just wet with fuel... I could tell the difference... it was thick and grey and completely saturated. If I changed out the plug it would run and idle fine... As soon as I rode it for a minute it loaded up and fell on its face... Think about it... The more I revved the bike, the more powerful the negative pressure became from the right side of the motor to the actual crankcase... Hope this helps!

[TRexRacing]

Why are you running an old air cooled bike at 75:1?If you're running this fuel/oil ratio at this rate without jetting accordingly you extremely rich.Try running some fuel through it at 32:1 if that's so.

[kschilk]

Sounds like it's starving for air. I know you cleaned the carb completely but there's a difference between completely and thoroughly. You mentioned a lack of mechanical experience and meaning no offense here...maybe you just didn't get it all. To really clean a carb, especially one that's been sitting awhile, you should rod-out and shoot compressed air through all of the passages. Simply using solvent or soap and a brush or dunking it in carb cleaner isn't usually enough. Often, all that'll do is knock loose some varnish or sludge that inevitably finds its way into a small passage and blocks it up. I use welding tip cleaners to rod-out all the jets and passages. Don't ignore the vent hoses, check for clogs. I put some small, trick-looking airline fittings in my airbox and routed my vent hoses into it, to keep them from getting fouled.

I'm still riding the doggysnot outa' my '83 CR480, had 'er from new. A finely tuned 480 (and I stress the term finely) is a world apart from stock....totally differnt bike. Pilot and main isn't usually enough, I had to change the needle and slide, also. It takes time, patience, money and a buddy that's really good at runnin' a stopwatch.

Before I start mine (cold), I put it in third gear and while holding the throttle at 1/2 to 3/4, I rock the bike back and forth to prime the cylinder. After putting it back into neutral, I pull the choke and one kick is all it ever takes. Warm to hot, I use no throttle or choke and it always starts with one kick. Yeah man, I looove my 480!