QuestionMark,
Three years ago I got back into riding after 15 years. I bought my father-in-laws '83 Honda VF750C in excellent condition. It has 31,000 miles on it. I have been running Vavoline 10W-40 Motorcycle oil in it. When I start the bike up the valves chatter loudly for at least 5 to 10 minutes until it warms up. Last year, right before my end of season oil change, I put in some Belray EXP Semi-synthetic 10W-40. It seemed like it helped quiet it down for my last couple of rides. Should I switch over to the Belray oil or should I stay away from a synthetic and go with a heavier oil like 20W-50?
AnswerHi Rich,
Check the oil container for temperature chart to verify which viscosity to use.
For most of the lower 49 United States climates, 10W40 or 10W30 is appropriate use.
Bel-Ray is very good synthetic motorcycle oil. It's okay to use regular mineral oils, too. The choice is yours. Despite the myths, switching between the two types of oils is okay.
Avoid using 20W50 to quiet a noisey engine. Instead, find the source of the noise and repair or adjust accordingly.
The early generation V-four Honda engine valve trains had problems. Intel available about this pasted below.
Respectfully,
Mark Shively
http://www.math.uwaterloo.ca/~rblander/V4_cams.html
The Dreaded V4 Cam Problem.
First generation Honda V4s are inadequately lubricated in the top end: simply not enough oil pressure or oil flow volume to keep the top end cool. Coupled with some soft cams in early years, this led to frequent erosion of cam lobes. Honda no longer gives away free replacement cams (although they did up until 1990 or so). Have your cams examined. Usually the rear cam of the rear cylinder pair is the first to go. To be fair, despite mild pitting a bike will run fine. Only severe pitting is a problem. Early GSXR750s had worse cam disintegration than the V4s ever had I'm told. Things you can do to help preserve your cams: use 10W40 premium oil such as BelRay SV4 or Golden Spectro. Change the oil a lot! Like, every couple thousand miles, none of this 8 thousand or whatever the owners manual says. Keep your revs up to help keep oil pressure up. This means drive in 4-5-6K rpm range, and don't dog it in 2-3K range while cruising. You can increase main jet one size up to enrichen the normally very lean mixture to make the engine run cooler. You can install a manual over-ride on the radiator fan so you can turn the fan on *before* the engine gets too hot. Or you can upgrade your rad fan switch to a newer Honda part that turns the fan on at about 50 degrees lower temperature.
A complete set of camshafts and rocker arms will cost you about $1000 to $1200 or so. Unless they're in really rough shape, you can usually get by without doing this. Even in the worst cases, the bikes still ran okay. If your cams are in good shape, you might want to consider a kit to improve oil flow to the heads. One for $250 was sold by Tierney Hollen Engineering. I installed it on my bike and I think it's great. Here's a photo, but about all you can see is the braided steel hose that comes up from the disc behind the oil filter to the cylinder heads.
There's a lot more to be said on the cam topic. Refer to the "Honda V4 Cam Story", available from yours truly.
