RC36 faint smoke from behind the radiator

[Guest Myyra]

Hello everyone.

I have had a VFR 750 1991 for a year now, and she has been as good a 21 year old bike as possible. (Around 77000km on the clock)

After taking her out from winter storage few weeks back, she started after a few tries and I was terrified to see some smoke coming out from under the fairings, around the front exhaust headers, as well as more white smoke from exhaust than normally. However as she had been sitting for 3 months I figured the exhaust smoke was mainly condensed water (it was a cold day, well, as warm as we get here in Finland in March) and then remembered I had been a bit excessive with the WD-40-like spray and it probably burned off the headers after they warmed up. Surely enough, the smoking ceased after 10 minutes and I rode happily around for a few days. After a week of renewed snowing (and much swearing from my part since it had just melted 2weeks before) the long-awaited spring started for good this time and I took the VFR to the mechanic for a 24000km thorough maintenance and asked him to look for leaks as he was checking the spark plugs and valve clearance. Everything seemed fine. However this week when I was riding around, I thought I saw some faint white smoke coming from the area you see when you look right past the forks inside the fairing as I was sitting in red lights. I thought this was only water evaporating since it was a wet day. However, two days ago the same effect came back and as I parked the bike I left it running to check around the radiator. Sure enough, there was faint whitish (exhaust-looking) smoke emanating from right under the lower border of the rad, but it didn´t seem to come out of the radiator itself, more like from behind it or somewhere I could not see properly. It didnt smoke continuously but it seemed to come a few small puffs at a time.

What could be wrong? It was a wet day that time, too but the smoke did not seem to be water, it was too white IMO. The bike runs at normal temperatures afaik, the exhaust smoke is not thick, the power seems to be there normally, and no other symptoms are present. This seems to have come after the maintenance visit a few days back, but is so small I wonder if I just haven´t seen it before.

Picture related, my bike from last summer :)

[samaki]

I suspect that you have a water leak at a radiator hose connection. If your spark plugs were changed or valves adjusted at the last 24000 km service, the radiator would have been disconnected. It is likely that the hoses were not reattached properly or a hose clamp has been left loose. Should be an easy fix.

[Cogswell]

Sorry for your trouble - hopefully it's minor. Mostly I wanted to say that you have a really nice looking 3rd gen! I don't recall seeing graphics like that on that year - were those Euro spec only or something custom?

[Dutchy]

Hyyva huomenta and welcome to VFRD!

top left of your screen there is a more pulldown menu

ciick downloads and go to pg 7 of the owners manual and others

there you find the 90-97 manual which will show you excactly how the cooling should be routed/connected (and all other parts of your bike)

[JZH]

Standard Euro-spec VFR750FM (except for the white bit on the turn signal housing).

Ciao,

[Guest]

Thanks for the answers! I already have the manual so I´ll be doing some checking out today and will tell you how it worked out.

And yes, the side graphics are custom stickers. Luckily mine already has the rear licence plate holder removed, it really spoils the look in the otherwise cool picture!

[Guest]

The fix seems to have worked. Thanks again!