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Discussion Starter · #1 ·
Hi. I have recently finished my Neo 181 bbk and now running it in,but have checked and although correct have reset 3 times the valve clearance to 0.1 (0.004) and 0.17 (0.007) but still engine is very noisy ticking Away! Haven't gone flat out yet as running in but seams to be going fine, but is there a different valve clearance value used on a BBK and not the same as the standard 125?? (do have a couple more issues to ask but tackling them one at a time!) THANKS
 

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The valve clearance spec is going to depend on the cam, so if you've still got the stock cam, those are the values to use. (Or does the neo come with its own cam?)
Are you sure the ticking is coming from the tappets? It could simply be the valves closing, or a more worrisome issue, the valves hitting the piston. Id check the timing to make sure its on the correct tooth, and if correct, pull the head off and check the piston too.

I remember someone saying the larger injectors also click louder too, so it could be that?
 

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Discussion Starter · #3 ·
Neo comes with its own cam. Have checked the timing and all good there. Maybe will have to take head off to check like u say the piston isn't hitting the valves. It does seam to go OK but haven't been above 7800 revs yet and don't want to destroy it if something is wrong. Only thing I have seen is that rocker arms are reused from original head which are fine. But when feeler gauge is in between on the exhaust valve u can see that it is tight in one place but a slight gap in another. Should I grind the tappet to fit dead flush (flat surface to flat surface.) Just would of thought that although not perfect contact on the two surfaces where they do touch is where the feeler guage was used and as such it should be opening and closing with the correct gap? Unless the neo 181 has different valve gaps?
 

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Discussion Starter · #7 ·
Ok will run it some more. Enjoyed the building the engine bit but sorting out little issues, which I have more of, this site is invaluable for. Thanks for the help.Someone said that different cams can make it sound loud and ticking. Listen to a uk forum site vid on my issue and that bike sounded very simular,so could it be just that?
 

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yup. cam profiles and how quickly the (or aggressively) the cam closes or opens the valve can affect noise. keep in mind, its better to have them a bit too loose vs too tight. reason being is that if too tight calve can hang open and you can burn a valve up.

on the OLD cb750 sohc motors, they are rocker arm as well. when we used to put hot cams in them and the rpms would go up from stock, we used to go a bit large on the clearances to allow the valves to close completely since you got soem float at a very high rpm with stock clearances. pretty common practice with these old dinosaur rocker arm setups like the grom has. :toothy5:
 

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The ticking is normal, don't go crazy over trying to solve it. My NEO 181 does that same damn thing.
 

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The manual is no longer available online, and the kit seems to be discontinued.

Still have my manual. Valve lash is as quoted, attached. Units are in mm

View attachment 93214
View attachment 93215
View attachment 93216
View attachment 93217
unfortunatelly, there is no length of the valves in this sheet.
I want to install a cam with much more travel, which i checked in an old series-head to measure the timing and travel.
Both are much more agressive.
In this OEM-head, the valve spring retainer hits the valve guide, so i had to modify some parts only to measure the cam (without valve stem sealing).
Before i dismount my engine, i would like to know the length of the valves (OEM is 72.5 mm).
Can anyone help me with this information?
Thanks, Klaus from Germany
 
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