What is that noise???

Hi VF Owners, I have a potentially BIG problem with my 83 VF750F. I have owned the bike for the past four years, and it has had all of its regular service, using Honda GN4 oil. The bike is ridden regularly with 33000 miles, and is in fantastic original condition, I will try to post some pictures. I have not had ANY trouble with this bike.

I was passing an 18 wheeler last week, and ran up to about 85mph, LONG after the bike had been warmed up, and i was into the last 6 miles of my 60 mile R/T ride. as i was coming into town i could hear a very pronounced rattle coming from the engine, especially on the downshift. At idle you don't hear it, but bring the RPM's up and it is definately audible. It seems to be coming from the upper end of the front cylinder head. I checked the oil, and it was about midway down on the dipstick, and clean. Any ideas what this noise is? Any tests i can do? where should i start!! Let me know if i need to offer any more clarification.....

I appreciate the help!

 

I'd check the cam chains first. Sometimes the tentioners can get stuck or wear out. These 1st gens can also wear out the cams which makes a chattering sound. The cams are a VERY expensive repair, so cross your fingers it's the chains.:violin:

 

Could it be the exhaust headers rattling?

 

I have checked the exhaust headers, and the bolts seemed to be snug. It really sounds like a cam chain or tensioner, or even a piston slapping......

 

I've never heard of a 1st Gen with piston slap, but tons with cam/cam chain trouble.

 

I'd check the CCT's first. Very common problem and an easy fix.

 

Cam Chain Is What I Would Replace, I Work In A Honda Dealership In Parts And My Mechanics A While Back Hat A 86 Vfr In And Advice That The Cam Chain Shoulbe Replaced Every 20000 Miles

Crazy K

 

The CCT sounds like the place to start, does anyone have a Specifically detailed proceedure for camchain replacement, and tensioner replacement? Where can i find one. I have a Clymer manual, but thought i would see if anyone else has a nice step by step with photos.......

Thanks

 

I have owned 2- 1983 VF750F models and they both needed cam chain tensioners after the 20,000 mile mark...Its not hard to replace them/ takes about 2 hours... The rattling noise is the first sign of a bad tensioner..

The cam chains should be fine as its the tensioners that go bad and cause all the noise as the cam chain goes slack then tight.

 

86 vfr is gear driven cams.. Yes to changing the cam chain tensioners on 1983-1985 models every 20-30k miles.