Engine Noise? - Motorcycle-Journal Forums

Damian2888 · 07-11-2006, 08:42 PM

Okay I own a 1984 Honda VF750F interceptor. I hearing a slapping noise in my engine. Now I have determined its not piston slap...not low octane. The noise is constant..weather idling slowing down or going fast. This puppy is a v-four and it has chains in the engine. Im not sure what this noise is..but i need some help here...shops are too much $$$ and lets face it not everyone is a mechanic. I thought it could of been maybe valve noise? but i cant be sure...the weird thing is the noise is in both heads...but slightly louder in the rear head. Can anyone think of anything that maybe the cause of this?

jpwM50 · 07-11-2006, 09:33 PM

Sounds like valves to me. That motor was notorious for major repairs, hope thats not the case here.
They don't call it the interclunker for nothing...sorry I had to say it.

Shea · 07-11-2006, 09:35 PM

Coule be a couple different things. I would check the primary first. That will be the easiest and quickest fix. First, make sure the chain isn't loose, secnd, make sure the primary nut is tight.

it may get pretty invloved after that.

Damian2888 · 07-11-2006, 09:42 PM

okay well..the chain..according to my brother(honda tec..cars) says its not adjustable...now youd think why dont i ask him to fix it?....you wont touch my bike...so...yah all i can seee now is the vavles and that involves engine ripe out..which is mechanically beyond me..

Shea · 07-11-2006, 10:00 PM

Quote:

Originally Posted by Damian2888

okay well..the chain..according to my brother(honda tec..cars) says its not adjustable...now youd think why dont i ask him to fix it?....you wont touch my bike...so...yah all i can seee now is the vavles and that involves engine ripe out..which is mechanically beyond me..

Of course, the chain on cars is not adjustable, but it is on most bikes.

Honda bikes are not Honda cars.

Take off the primary cover. lift the chain with your finger, it should only move so much. each bike may be different, but, I am htinking that a half to 3/4 inch is all it should move. I could be mistaken. If it moves alot, then it needs adjusted. If it looks ok, check the torque specs on the primary nut. You may need to get a new one. They usually recommend using a new one, clean, so that it's not stripped at all and being clean will be better for the lok-tite.

Best thing to do is find a service manual for it. That will tell you everything you need to know.

Damian2888 · 07-11-2006, 11:43 PM

I got the maual for my bike..but i mean to check what your saying means taking the engine out of the frame..id imgaine thats alot of work...and alot of fluid drainage...

Shea · 07-12-2006, 10:44 AM

Quote:

Originally Posted by Damian2888

I got the maual for my bike..but i mean to check what your saying means taking the engine out of the frame..id imgaine thats alot of work...and alot of fluid drainage...

Really? Usually the primary cover is on the outside part of the engine.

http://www.vf750fd.com/vf750f/vf750f.jpg

Isn't that silver cover in this pic the primary cover?

Damian2888 · 07-12-2006, 08:18 PM

no that would be the clutch cover...to do the valves, or chain...the engine must be removed becuase the covers are under the gas tank...and its too tight to take off with the engine in frame.

Shea · 07-12-2006, 09:03 PM

Quote:

Originally Posted by Damian2888

no that would be the clutch cover...to do the valves, or chain...the engine must be removed becuase the covers are under the gas tank...and its too tight to take off with the engine in frame.

What's on the other side? It looks like it has the same cover on the other side? That is really weird that the primary isn't there. I don't understand how the bike works if the primary is in another location.

Damian2888 · 07-12-2006, 09:38 PM

the other side is the...hmm..where the oil goes..im not sure what is called...my manual shows the top of the engine out of frame with the chain sticking out with the valve adjusters beside them....make sense?

JoelAZ · 07-13-2006, 12:37 AM

When you say "The noise is constant..weather idling slowing down or going fast." Do you mean that the noise speeds up and slows down with the engine speed?

JoelAZ · 07-13-2006, 12:39 AM

Quote:

Originally Posted by Shea

What's on the other side? It looks like it has the same cover on the other side? That is really weird that the primary isn't there. I don't understand how the bike works if the primary is in another location.

Most import bikes have internal primary drives. The crankshaft spins the clutch basket and the inner hub is splined to the transmission mainshaft. The transmission is part of the motor. It is very different from the Buell which you ride.

Shea · 07-13-2006, 11:27 AM

Quote:

Originally Posted by JoelAZ

Most import bikes have internal primary drives. The crankshaft spins the clutch basket and the inner hub is splined to the transmission mainshaft. The transmission is part of the motor. It is very different from the Buell which you ride.

Thanks, I didn't realize that.

Damian2888 · 07-14-2006, 08:11 PM

yah like the faster i go its seems like it gets louder...

JoelAZ · 07-15-2006, 01:41 PM

Quote:

Originally Posted by Damian2888

yah like the faster i go its seems like it gets louder...

And you said you hear it from both heads, one louder then the other?

Aside from actually hearing it for myself, I'd go ahead and say you have a rod knock. This would require a full engine rebuild.

Whatever you do, do not got wide open throttle on this engine until you can get it fixed. Wide open on a rod knock is asking for your engine to grenade.

Damian2888 · 07-16-2006, 05:13 PM

oh thats nice...an engine rebuilt you say..thats...nice..this should be a long expensive fix

Damian2888 · 07-16-2006, 08:31 PM

well acually..now that i think about it...a rod knock?..cant be..its not a knock...its more of a tick/slap...also..since i have had this bike..i have been...punching it..alot

JoelAZ · 07-20-2006, 12:28 AM

could be piston slap... In which case the only solution would be to overbore the engine... I still stand by my suggestion of not going WFO...

Damian2888 · 07-21-2006, 07:38 PM

yah i agree ill just cruise with it

07-11-2006, 08:42 PM	#1 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	Engine Noise? Okay I own a 1984 Honda VF750F interceptor. I hearing a slapping noise in my engine. Now I have determined its not piston slap...not low octane. The noise is constant..weather idling slowing down or going fast. This puppy is a v-four and it has chains in the engine. Im not sure what this noise is..but i need some help here...shops are too much $$$ and lets face it not everyone is a mechanic. I thought it could of been maybe valve noise? but i cant be sure...the weird thing is the noise is in both heads...but slightly louder in the rear head. Can anyone think of anything that maybe the cause of this? __________________ Riding Is My Only Cure

07-11-2006, 09:33 PM	#2 (permalink)
jpwM50 Clutch Cadet Joined: Jul 2005 Bike: Blue M50 Location: Waterloo, Canada Posts: 944	Sounds like valves to me. That motor was notorious for major repairs, hope thats not the case here. They don't call it the interclunker for nothing...sorry I had to say it. __________________

07-11-2006, 09:42 PM	#4 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	okay well..the chain..according to my brother(honda tec..cars) says its not adjustable...now youd think why dont i ask him to fix it?....you wont touch my bike...so...yah all i can seee now is the vavles and that involves engine ripe out..which is mechanically beyond me.. __________________ Riding Is My Only Cure

07-11-2006, 11:43 PM	#6 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	I got the maual for my bike..but i mean to check what your saying means taking the engine out of the frame..id imgaine thats alot of work...and alot of fluid drainage... __________________ Riding Is My Only Cure

07-12-2006, 08:18 PM	#8 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	no that would be the clutch cover...to do the valves, or chain...the engine must be removed becuase the covers are under the gas tank...and its too tight to take off with the engine in frame. __________________ Riding Is My Only Cure

07-11-2006, 09:35 PM	#3 (permalink)
Shea Third gear and cruising Joined: Feb 2006 Bike: Buell XB12Ss Lightning Location: York, Pa Posts: 521	Coule be a couple different things. I would check the primary first. That will be the easiest and quickest fix. First, make sure the chain isn't loose, secnd, make sure the primary nut is tight. it may get pretty invloved after that.

07-12-2006, 09:38 PM	#10 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	the other side is the...hmm..where the oil goes..im not sure what is called...my manual shows the top of the engine out of frame with the chain sticking out with the valve adjusters beside them....make sense? __________________ Riding Is My Only Cure

07-13-2006, 12:37 AM	#11 (permalink)
JoelAZ Seat Tester Joined: Feb 2006 Bike: Still under consideration Location: Phoenix, AZ Posts: 88	When you say "The noise is constant..weather idling slowing down or going fast." Do you mean that the noise speeds up and slows down with the engine speed? __________________ -Joel mmMMmmMMmm.... tasty!!! (\__/) (O.o ) (> < )<-- This is Bunny. Copy Bunny into your signature to help him on his way to world domination.

07-14-2006, 08:11 PM	#14 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	yah like the faster i go its seems like it gets louder... __________________ Riding Is My Only Cure

07-16-2006, 05:13 PM	#16 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	oh thats nice...an engine rebuilt you say..thats...nice..this should be a long expensive fix __________________ Riding Is My Only Cure

07-16-2006, 08:31 PM	#17 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	well acually..now that i think about it...a rod knock?..cant be..its not a knock...its more of a tick/slap...also..since i have had this bike..i have been...punching it..alot __________________ Riding Is My Only Cure

07-20-2006, 12:28 AM	#18 (permalink)
JoelAZ Seat Tester Joined: Feb 2006 Bike: Still under consideration Location: Phoenix, AZ Posts: 88	could be piston slap... In which case the only solution would be to overbore the engine... I still stand by my suggestion of not going WFO... __________________ -Joel mmMMmmMMmm.... tasty!!! (\__/) (O.o ) (> < )<-- This is Bunny. Copy Bunny into your signature to help him on his way to world domination.

07-21-2006, 07:38 PM	#19 (permalink)
Damian2888 Seat Tester Joined: Apr 2006 Bike: 1996 KAWASAKI NINJA ZX6R F2 Location: Canada Posts: 95	yah i agree ill just cruise with it __________________ Riding Is My Only Cure

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