help with diagnosis

hello... this is my first time posting, i am here because my 1985 honda vf700f has a ticking and i dont know exactly what it is. the ticking is coming for the valve cover area and the number 4 cylinder. there is only 18,000+ miles. i am the second owner of it and i have personal put about 1000 miles on it. i dont race it, dont over rev it, but it had a ticking when i first got it and it was quiet. now after personally putting 1000 miles on it, its louder... is it the rockers? cam? valves? please help

 

It could be a lot of things but a ticking, that loud, is never good. It could be a broken spring or busted keeper. Do not run that engine. Get that valve cover off and have a look. Someone with more VF experience than me can give you better advice.

 

Typically a rocker, but who knows...
I've got a 4 pot 16 valve screw adjusted rockers engine that required maintennance every 15Kmiles
As said before, open thar cover and check clearances first... Don't ride if you don't have to.

 

did you notice if it was louder at idle than above idle or vice versa, louder at revs than at idle? makes a difference

 

I cant tell if it's louder at higher rpm because my exhaust is loud. At idle its pretty loud and i plan to take the cover off and investigate this up coming weekend.

 

The valve trains on the early VF's had many problem. The rockers developed dished spots and the cam chain tensioners had problems. You will not see the rocker dishing problem by just taking off a valve cover. You need to actually remove the rocker so it isn't blocked by the cam. You will find lots of threads on here about worn rockers. the ticking starts small but quickly gets loud. The cam may or may not look worn for the cylinder causing the noise. The rockers were flash chrome plated in the wear area and when the plating fails the rocker wears very quickly.

 

So worst case possible... id have to replace the cam and rocker?

 

Yup... Prepare for the worst and expect the best.

 

I had to adjust my valves a few times to get it right.
Then less than 500 miles later I started getting noise from the rear chain again. My best advice (at least if everything's in fair shape up top) is to study up on valve adjustment, various oil mods, as well as how to get the timing chain tensioners going if they are stuck.

Valve adjustment is very tedious and requires 2 identical feeler gauges and something to lift and hold the cam in its journals, I prefer the Dave dodge method with the exception that I adjust with 2 .005" feelers on top of the valves rather than 1 .003" feeler between the cam heel and the rocker.

Oil mods can be as simple as opening up the holes in the banjo bolts that feed the heads, and making sure the speakers are properly aimed, to a full on pull the motor and tap into the main oil galley and run lines with the proper amount of restriction to the heads.
You should at least run a quality (Napa gold 1334 IIRC) oil filter, and oil (Spectra Gold, Mobile Synthetic) ,and change it frequently as well as open up the factory lines as per the link below.
http://www.math.uwaterloo.ca/~rblander/V4_phil_mod1.html
http://www.math.uwaterloo.ca/~rblander/V4_phil_mod2.html

Additional information
http://www.math.uwaterloo.ca/~rblander/V4_JL_oil.txt
http://www.math.uwaterloo.ca/~rblander/V4_AR.html

www.google.com/search?as_q=V4&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=http%3A%2F%2Fwww.math.uwaterloo.ca%2F~rblander%2F&as_occt=any&safe=images&as_filetype=&as_rights=

The above is only from one source much more info is out there.

Enjoy and good luck

db

 

If it is the cam rocker problem you will discover that you cannot get these parts easily or cheaply. Most people who have repaired the bikes seem to just get used parts or maybe a whole engine. There are companies which will regrind your original cam.
You will find discussions on oil supply mods and many people put those kits on. It's questionable whether they really were needed as Honda looked into the oil flow when they were troubleshooting the failures.
A really good discussion of the many factors involved can be found here: http://www.motorcycleproject.com/text/v4_cams_what.html

Another common problem is valve failure causing severe engine damage. You can find pictures of holes in pistons and damaged heads. No one knows definitely what is the root cause. Some suggest valve springs are the cause but I haven't found any real engineering analysis that points to a specific part(valve, spring, keeper)

 

http://www.webcamshafts.com/index_blank.html?pages/vehicle_search.html
maybe get hold of these people if you do need parts. I just got rockers from them for a atv project they are great to deal with got my parts in 1 business day.

 

very good article, makes want to replace the rockers with hard welded ones while my cams are still nice and pit free.
Seems as long as the cams don't put and the top doesn't get oil starved.... that the chrome plating might be safe anyway. Seems the rockers would be a necessity if going to a stage 1 or 2 cam. Lots of other work to take place before a bit more power will help the old vf .