Topic: Primary chain - how do you know if it needs replacing - throttle snatch?

[loonymoon]

Hi,

 I was just browsing www.cmsnl.com which has a lot of parts for the 350F. I came across this description for the primary chain:

CHAIN,PRIM.DRIVE

If you are developing unwanted amounts of transmission snatch, particularly at low town speeds when shutting off and then re-opening the throttle, maybe it is time to replace the primary chain, with a fresh, new part that will tighten up that back-lash, that is so annoying, and potentially damaging.

I noticed that when I did my ride to epping forest that I recorded on You -tube I did get quite a lot of snatch when at low revs slowing down or pulling away. However I mainly put that down to me not being used to the bike any more and having been riding an automatic scooter for so long.

The bike only has 11,500 miles - do you think it is time for a primary chain change? ( it had a new drive chain recently)  Or could it just be me being inept? I admit when I rode to the classic bike show I didn't notice it so much so either I could have got used to it by then, or perhaps it was just that I wasn't travelling at slow speeds for most of the journey!

I'm just slightly worried by the "potentially damaging" part of the description...

[Gordon]

You seem to be exhibiting symptoms of first stage "Bikeochondria".

11K is nothing for a primary chain.  What's more likely is that your drive chain slack just needs to be tightened up a little. 

[bistromath]

Make sure you've properly tightened the drive chain before you consider the primary chain. First symptom of worn primary chain is primary chain slap, which manifests itself at idle. Take the oil pan off and feel the play on the primary chain directly.

At 11,500 miles I'd be amazed if the primary chain was shot already. Previous owner would have had to drag race it for every one of those miles. Tension that drive chain properly and just accept a little bit of lash, it's normal.

[kghost]

Looney,

The 350 was always a bit snatchy as it is......

Mine is fairly abrupt rolling on and off.......

Seems a function of the bike/engine coupling....400F is like that a bit but not as bad.

I have 18,000 on mine...and its not the primary. I flog the living daylights out of mine. 

[loonymoon]

bikechondria - yep probably what it is. 

I thought 11500 was too low for a worn chain... but thought I'd check anyhow.

Drive chain was installed by a decent mechanic  - but I will make sure it's not too slack too.

[mattcb350f]

Looney,

The 350 was always a bit snatchy as it is......

Mine is fairly abrupt rolling on and off.......

Seems a function of the bike/engine coupling....400F is like that a bit but not as bad.

I have 18,000 on mine...and its not the primary. I flog the living daylights out of mine. 

Mine too. And It's got a new chain.

Remember there's no tensioner on the 350F either so the slap is probably more noticable than on the bigger bikes (I think the 750's have a tensioner  ).

 Matt.

[bistromath]

Slack's gotta be adjusted every few hundred miles or it'll get out of hand. Keep on it.

[kghost]

Slack's gotta be adjusted every few hundred miles or it'll get out of hand. Keep on it.

That used to be true.....

The honda recommended service interval is 500 miles (Page 54 Owners Manual)

Chain quality is a bit better these days.....

I've seen 1000-2000 between some adjustments with a high quality chain.

 3/4 inch is the correct slack...more requires adjustment