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Discussion Starter #1 (Edited)
so I just had my valves adjusted along with the cam chain and a new front tire. so when I pick up my bike from the shop the valves have quieted down a lot bike sounds a lot better than before. He also adjusted the idle on the carbs, he said one cylinder wasn't firing at idle. the bike idles great seems to run well.so long story short I attempt to take off with some power but the engine doesn't want to spin much in gear and seems like it makes a hesitation/backfire noise when the revs start to get high. it never did this before and used to have great power. he said one of the valves was way out of adjustment, which im guessing he adjusted within spec. (I also want to note the right cylinder seems to make the spark plug black, also the valve in question was harder to adjust than the others) my mechanic thinks the cam and possibly the journal for the cam in the head is worn out. I was wondering if this all makes sense and im not just throwing parts at the wrong problem.

also the bike drives around town fine at grandpa revs, just doesent feel/perform right.
thanks for your time
 

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You need to re-check the valve adjustments. You may also need to do a carb sync.

It would be really helpful if you would do an introduction to let us know about yourself and your bike, specifically how mechanically inclined you are. Working on these bikes isn't particularly difficult though I have known some carpenters who just couldn't get the hang of it.

You might also add your location to your profile and create a signature with the model of your bike.
 

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Welcome aboard
In the mechanical world thinking means I haven't checked or I don't know. Mechanical's are either right/good or wrong/bad.
First you need a good shop manual, specfically the Honda Factory Service Manual (FSM), don't bother with anything else.
Performance should not have degraded from having it serviced unless something was done wrong. I would start with the valve adjustment, timing chain adjustment and balancer chain adjustment. Then check the compression. Be sure the correct sparkplugs are in it. Set the mixtures and see where that takes you.
Ask if you need the shop manuals, 1986 is different than the 82-85 manual.
 

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Discussion Starter #4 (Edited)
He switched out one of the plugs from before it was worked on. was wondering if a ngk d7ea works ok with this bike, what he used. not sure what ngk the other is. I switched the plugs around, the newer one is the only one that seems to get black. the bike is a 82 nighthawk 450 with 56,000 miles on it
 

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Standard plug for your bike is NGK DR8ES-L. The D7 is a slightly hotter plug and non-resistor. As long as the plugs aren't fouled you shouldn't notice any significant difference in performance.
 
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