Knock when cold starting

[cmacrider]

I have an 08 that seems to have a brief "knock"/"clunk"/"thunk" (whatever) when starting it cold.

The bike only has about 16,000 miles on it. It only "knocks" 2-3 times just after firing it up. It does this within the first second and then it goes away. After its warmed up and restarted, I don't hear this.

It starts fine and runs well. All maintenance has been done as required. Could it be a bad plug, coil, valve?

Any comments will be appreciated.

Thanks,

Mac

 

[bluesdog]

Probably nothing amiss.

Mine used to do that fairly regularly. One or two 'hiccups' when started cold. iirc, it's nothing to be concerned about, but I agree it's annoying.

I resolved it by adjusting the idle speed to 1100 RPM when engine is fully warm, AND by performing the unauthorized TBS

 

[MrZappo]

Non issue. It has something to do with the anti polution stuff I think. Goes away as soon as it warms a bit.

I have seen a few fjr's do this and never seen a problem as a result.

 

[RossKean]

If your cam chain tensioner is original, you might consider replacement. The sound of a bad CCT is probably described more as a rattle than a knock but a failure would ruin your whole day (or riding season). Have a listen on the lower right of the engine next time. It might be nothing, but...

An '08 with only 16,000 miles???

 

[cmacrider]

I have an 08 that seems to have a brief "knock"/"clunk"/"thunk" (whatever) when starting it cold.

The bike only has about 16,000 miles on it. It only "knocks" 2-3 times just after firing it up. It does this within the first second and then it goes away. After its warmed up and restarted, I don't hear this.

It starts fine and runs well. All maintenance has been done as required. Could it be a bad plug, coil, valve?

Any comments will be appreciated.

Thanks,

Mac

 

[Fred W]

Completely normal, there is nothing wrong with your bike. Nothing to worry about

Been talked about here a lot. The engine is just having a few misses at idle during the warm up. Does not affect the ride-ability, even when still cold, as it only happens at idle.

 

[Fred W]

CCTs don't only make noise when the engine is cold.

Sounds more like the normal warm up misfires to me.

 

[RossKean]

CCTs don't only make noise when the engine is cold.
Sounds more like the normal warm up misfires to me.

Difficult to tell what sounds he is hearing from the description. I was under the impression that CCT noise was worse with a cold engine. Even so, it would last for more than a few seconds.

As I mentioned, it may be nothing but it certainly wouldn't hurt to have someone who knows FJRs to have a listen.

 

[Mihalis fjr]

A video could help a lot!

 

[YummYam]

Mine usually does this. I think of it as a cough, kind off throat clearing!

+1 with MrZappo and Fred W.

 

[08FJR4ME]

Totally normal, no worries. 73K miles

Dave

 

[FJReady]

Ya, not to worry. Mine's been doing that for over 100K miles. Just do your routine maintenance when it's due and you'll be riding that bike a long time!

 

[Uncle Hud]

Duplicate? https://www.fjrforum.com/forum//index.php/topic/161899-knock-when-cold-starting/

 

[ionbeam]

Duplicate? https://www.fjrforum.com/forum//index.php/topic/161899-knock-when-cold-starting/

Ya, but this time it's only two this time, nothing compared to what the real finger flickers have done in the past.

 

[Bounce]

duplicate threads merged

https://www.fjrforum.com/forum//index.php/topic/150102-avoiding-doubletriple-postings/

 

[entonox]

Aye our works FJR 08 with 38k on the clock has similar symptoms.....................runs perfectly fine. For an abused paramedic bike that's is