GT 750 top end rattle 3-4000 rpm.

[Exmoor beast]

Where did you get your "tappets"?
Paul

Scotland!

 

[Exmoor beast]

Longest 30 seconds of my life waiting for oil to come out of rocker spindles with both finned covers off, just about to give up and cry when out it came! Had to run it with no pipes as new ones haven’t arrived. Timed it up, oil in, battery on , fired up on the button. Hopefully I’ll be ok for the weekend…

 

[Tippie]

Looking through open tappet covers with it running is enough. With the finned cam end covers removed the oil won't go through the rockers onto the cam. Ok if just spinning it over on starter motor but don't run it like that.
Happy that it all seems in order now.

 

[chrisk]

I experienced, what sounded like a top end rattle, at 3,500 revs and up.

It turned out the be the tensioner roller, was shaped like a D, instead of O.

Presumably the roller acted as a triple and 500 blade until the revs got higher, then bounced back and forth as it started to spin.

 

[Paul Marx]

T

I experienced, what sounded like a top end rattle, at 3,500 revs and up.

It turned out the be the tensioner roller, was shaped like a D, instead of O.

Presumably the roller acted as a triple and 500 blade until the revs got higher, then bounced back and forth as it started to spin.

They all do that.
Paul

 

[Exmoor beast]

I’ve fitted a set of Phil Todd nylon wheels, 2 x camchain and a primary chain wheel

 

[Exmoor beast]

Got the old beast running and went for a blast, all good. The original resonant rattle has gone- so I conclude it was valve top/ guide/spring wear related and not “pinging” which is what it sounded like..I purposely didn’t change anything to do with the timing ( still on points) so I could get a definitive answer .I think the valve tops wearing Is the root cause- why the exhaust more than inlet I don’t know? Im running it on a 20/50 semi synthetic with 1500ppm zinc so hopefully that Should keep the top end sound. That was a bloody long winter rebuild..