CB750 K7 problem accelerating

[Beatnic]

Hello guys! New to the forum, and new to bikes, so please have some patience. I bought a nice smooth-running all original Honda CB750 K7 last summer and everything was working great. This year it suddenly started dying on me, or going "boooowwwouuu", with fast throttle movement. Checked the accelerator pump... Didn't work. Opened carburettor and cleaned out all small fuelvalves and pathways. Put it all back together (damn airbox took forecer to get in place) and all worked fine. Until today when i went to tighten cam-chain. Did as i've read you should. Removed tappet cover on no1 valve to check that valve is closed at tdc, loosened the tensionbolt, and retughtened BUT forgot to put the tappetcover on no1 back on. Whent for a ride, and engine was again going booooowwwouuuu upon acceleration... Noticed the cover was off after the engine sprayd my jeans (yeah, felt like an idiot) and slowly rode home to put the cover back on. Have i caused any huge damage to my bike? It still dies and looses all power now that the cover is on. All help greatly appreciated! Thanks!

[TOOLS1]

No you did not hurt the engine, as long as it still had oil in it. The best way to adjust the cam chain is to loosen the bolt on the adjuster and then manually crank the engine over (just a little is all that is needed) with the kick starter, or a wrench on the end of the crank. This will remove the slack, then tighten the locking bolt back down, done. However sometimes I have found stuck adjusters, so I often take a bent screwdriver, and use it to push on the end of the adjuster through the hole in the end of the housing.
Withe the limited, but cute information "boooowwwouuu" you gave on your running problem, I would suspect a fuel problem. Check fuel flow, the vent in the gas cap, float height, dirty jets...
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[Beatnic]

Thank you TOOLS! Great info on the cam chain! By biggest problem right now is the weird loss of enginepower when accelerating,  which for some reason got a lot worse after i adjusted cam chain and rode the bike without the tappetcover. I get really slow acceleration, and it wont accelerate past 80 km/h. Also dies if i hit  the throttle fast (well, not fast really. More like you normally would when accelerateing).

I really dont understand what could cause the problem, since after cleaning the carbs the bike was running fine. Thats why i thought leaving the cover open while running (which was when the problem started) must be connected. I can make a video of what it sounds/looks like right now, if that would make it easier to troubleshoot. Thank you so much far taking your time to help me out!

[TOOLS1]

The cover being off would not have anything to do with running. I wonder if you might have knocked something else out of whack when you adjusted the valves, and cam chain. Are you having any other problems like erratic idle, or returning to idle slowly? Did you check your fuel line?
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[deskinthewoods]

Hi. New here but this sounds like the problem I had. I tracked it down to the accelerator pump ports being clogged. I took the pump off and blasted carb cleaner throught the hole the pump pumps into until I had a good stream coming through all 4 ports (one in each carb).

They are here:



I had to do this twice, once 2 yrs ago and again the spring of last year, so it can be a recurring problem. I now add Seafoam to the tank every few fills to keep things flowing.

Hope this helps.

[shinyribs]

Any chance that the tappet cover being off let out enough oil to drown the nearest spark plug? Oil shouldn't short out a plug, but I've seen stranger things. Being in that general area, it's ready to bump things around. It's possible one of the plug caps is not making a good connection to the wire. They simply screw on to the wire. Check for a loose spark plug cap, or just unscrew them all and trim off a smidge of where if they don't seem healthy.

It's you cam chain quiet now or is it noisy? If something failed while you were adjusting the cam chain it's possible the chain is running real slacked , which could throw off the timing and make it lazy.