Did a compression test....not great

boyoboy said:
... Clean inspect set up carbs with the stock airbox will be easier to tune than pod filters....
Click to expand...

True that!
I would even hazard to say that correctly set up carbs connected to a well designed air box will out vastly out perform cheap pod filters and a free flow exhaust installed on this bike.

Your 1985 nighthawk 650 is equipped with CV carbs, they operate on vacuum, an inline 4 cylinder engine with 4 CV carbs and pod filters is a really really bad idea. Plus the nighthawk 650 is a heavy pig of a bike, I know this because I have one in my garage that I have been servicing for a friend and I don't even like to push it around. Bike needs to go on a strict diet before it could ever use more power. The suspension, the carbs, the wheels, the steering head bearing, swingarm, frame and the brakes all suck and this one even has a chain final drive. These engines have a chain primary drive and that is a terrible engine design to attempt clutch up wheelies with, all you are going to succeed in doing is bagging out your primary drive chain and ultimately destroying that part of the engine. It's a cruiser; trying to turn it into a performance bike will never happen unless you spend far too much money and time on it. Make it into a nice cruiser and ride it or sell it is your only logical option.
 
Last edited:
Trials said:
True that!
I would even hazard to say that correctly set up carbs connected to a well designed air box will out vastly out perform cheap pod filters and a free flow exhaust installed on this bike.
Click to expand...

I didn't want to say it. Pods may give a bit more power but not enough to make an impact on you. Plus you have to live with the intake howl of the pods.
And pods can be difficult to get the jetting right. unless you have someone gifting you the 4-1 I wouldn't spend money on the bike for a new pipe. Put the money in a "future bike jar" at home lol. edit-I would get the bike tuned good all stock and be happy with the old girl.
 
Last edited:
Trials said:
Do you want to just make it louder, perform better on the street or are you preparing it for track racing?
Click to expand...

I won't be tracking it I like it semi loud right now with my modified stock exhaust wind noise over power the exhaust above 80kph while crusing
 
Trials said:
True that!
I would even hazard to say that correctly set up carbs connected to a well designed air box will out vastly out perform cheap pod filters and a free flow exhaust installed on this bike.

Your 1985 nighthawk 650 is equipped with CV carbs, they operate on vacuum, an inline 4 cylinder engine with 4 CV carbs and pod filters is a really really bad idea. Plus the nighthawk 650 is a heavy pig of a bike, I know this because I have one in my garage that I have been servicing for a friend and I don't even like to push it around. Bike needs to go on a strict diet before it could ever use more power. The suspension, the carbs, the wheels, the steering head bearing, swingarm, frame and the brakes all suck and this one even has a chain final drive. These engines have a chain primary drive and that is a terrible engine design to attempt clutch up wheelies with, all you are going to succeed in doing is bagging out your primary drive chain and ultimately destroying that part of the engine. It's a cruiser; trying to turn it into a performance bike will never happen unless you spend far too much money and time on it. Make it into a nice cruiser and ride it or sell it is your only logical option.
Click to expand...

Hey no calling my bike fat lol. I'm not hard on it that often most time when I do shift when using a lot of throttle I roll into it.
 
One of the things often overlooked when installing pod filters is that there is no longer any support on the intake side of the carburetor.
All the weight is carried on the intake manifolds, which can then split and suck air.
Especially on an older machine, once you have it running, spray something like WD40 on those intake rubbers and see if idle speed changes.
If it does, there are more new parts to buy.
 
One of the functions of an air box is to provide a large volume of relatively still air for your carburetors to draw from. Above 80 kph your pod filters will be sucking turbulence and making all kinds of induction noise. You will no longer have a proper place to vent the crankcase and if you go with paper filters those will be exposed to rain and road spray which totally destroys paper filter material. If you go with foam or felt filters they will be needing regular cleaning and oiling to work properly and the excess oil will drip down on the top of your engine. You also need to install pods that don't block or interfere with the small openings in the throat of the carburetors, cheap paper pod filters often do just that.
At the very least you should incorporate a plenum for the CV carbs and attach to that one large logically located, oil treated air filter. That might gain you some performance without all of the nasty side effects, once you get it tuned to suit all your other modifications.
 
Knight said:
Hey no calling my bike fat lol. I'm not hard on it that often most time when I do shift when using a lot of throttle I roll into it.
Click to expand...

;) can I still call it a pig?
 
Another thing to consider is that pods don't really like getting caught in the rain, they are very likely to suck in water.
Need more power? Save and buy a different bike.

Sent from my SM-A500W using Tapatalk
 
Thanks for the advice I think I will just stick with the stock airbox and fix it. now to find a manufacture that make a 4-2 exhaust mac only makes it for the previous gen nighthawk and I'm not fond of the mac's tinny sound
 
TK4 said:
One of the things often overlooked when installing pod filters is that there is no longer any support on the intake side of the carburetor.
All the weight is carried on the intake manifolds, which can then split and suck air.
Especially on an older machine, once you have it running, spray something like WD40 on those intake rubbers and see if idle speed changes.
If it does, there are more new parts to buy.
Click to expand...

Its a pretty easy fix - use tie wraps or safety wire to support the carbs weight from above. just saying, IMO a stock airbox is the way to go on a street bike.
 
Would be good to hear more about solving the black plug/airbox leak. You may be pleasantly surprised at how much better your bike runs in good tune.

clutch up says zx600 !
 
You must log in or register to reply here.

Back
Top Bottom