The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: Sasel on 09.08. 2015 18:31

Title: engine knocks
Post by: Sasel on 09.08. 2015 18:31

Hello,

Could you please give me some advice. My Golden Flash likes to make a hammering metal sound when she is idling on half gas. no knocking on full throttel, just in the middle. So i change gears earlly. The engine is rebuild. Where shall i look?

Thanks from hamburg.

Yours Christian

Title: Re: engine knocks
Post by: RichardL on 09.08. 2015 19:10

Christian,

Welcome the forum. Please look here http://www.a7a10.net/forum/index.php?topic=4723.0 regarding a first introductory post.

You've given sparse info regarding the knocking - near the top? near the bottom? Etc. First guest is that it's valve related.

Richard L.

Title: Re: engine knocks
Post by: muskrat on 09.08. 2015 20:24

G'day Sasel.
My first thought is fuel related pinging. As Richard said, more info is needed.
Cheers

Title: Re: engine knocks
Post by: Triton Thrasher on 09.08. 2015 20:57

Try lifting the needle in the throttle slide. Put the clip in a lower notch.

Title: Re: engine knocks
Post by: metalflake11 on 09.08. 2015 21:34

I had similar, it turned out to be the throttle slide in a very worn Monobloc! I run without a filter so the noise was more pronounced.

Title: Re: engine knocks
Post by: RichardL on 09.08. 2015 21:39

Since there is a bent toward considering fuel: What grade fuel? What compression pistons? Lugging at low revs in 4th?

Richard L.

Title: Re: engine knocks
Post by: Sasel on 10.08. 2015 21:06

Thanks for your help. I use 95 octan fuel. I think the hammering is in the top of the engine. I am not shure. I can not here the knocking, when the bike does not drive.

Thanks a lot chris

Title: Re: engine knocks
Post by: duTch on 10.08. 2015 22:51

 Someone else had a similar issue not long ago, and a loose tank bolt was suggested. My RR tank bolt was completely stripped- I know the sound especially with an almost empty tank... *bash*

Title: Re: engine knocks
Post by: renos-a10 on 11.08. 2015 13:41

Hi to all again,

 First of all i think you must check all the screw on the bikes and specialy tank . One day i riding my BSA A10 Golden flash and i hear i think the same knock like this one .
 Second you must check again the valves gap and next the piston  compression .

Good luck
Renos