top end noise

[wilis]

i have a rattle type noise in rear head when hot, 860GT(not there when first started)mainly when backing off from high revs.have checked all i can think of.could it be lack of oil supply? (its like a dry tappet noise on a car).GW

[Lumpy]

Worn oil pump maybe??? Struggling to make pressure/flow when the oil warms up??

[wilis]

is there a simple way to check oil flow to rear head ?

[Lumpy]

I`ve got one of those gear gazer windows on mine. Friends rekon it`s a bit of a wank but it`s a good way to see you`ve got some oil flow happening. Interseting to note that on my two bikes oil flow is fairly slow to make it up to the back pot when you stop them and re-start when they are hot. Both have good oil pumps too. The gear gazer set me back about $90 a few years back but I rekon they are a good investment. Purely on a safety side of things. Most engines have some oil pressure warning system but a lot of bikes don`t. Considering the consequences of a seized engine on a bike with the rear wheel lock up issue. They are kinda hard to monitor while riding and I would`nt recomend that but at least you can see lube action before you take off

[wdietz186]

Assuming you've checked the valve clearance there are a few other things that can cause a tappet type noise. A loose valve guide[valve stem to guide] or a guide loose in the head,excess wear in the rocker spindle bushing[s],broken valve spring[not too likely],a worn piston [skirt wear],small end/piston pin wear,or what you don't want to hear,a worn big end.

[wilis]

thanks for your help will check again and let you know how i go.gw

[Craig in France]

I`ve got one of those gear gazer windows on mine. Friends rekon it`s a bit of a wank ...

Well Lumpy, if they were good enuf to be used by the factory when they fired the bikes up on the test bed, I reckon they should be good enuf for your friends ...

But impressive to see the oil flow, eh? Like someone turned on a tap ... (or 'faucet' to you Septics )

Ciao

Craig

[big phil]

hi mate. i had the exact same thing on a 86o gt. sounded like a irregular tapping noise from the rear head. sorry to say, it turned out to be a big end. the easiest way to tell is whip off the front cyl and barrel. if the piston is scored and has shiny bits in the skirt, big end.