Engine Knock Out of 1st Gear

[Rob F.]

I own an '08 R1200RT that is a year old and asked this questions when the bike was new but didn't get much insight so here it is again. I tend to think I'm a fairly good rider (6+ years). I had a '96 RT prior. In 1st gear, I release the clutch around 3K RPM. No more. There are times when the engine will knock. Is this caused by too little RPMs? Or is there a problem? What exactly is causing the knocking sound?

 

It is more pronounced it I am on an incline or if riding two up (so obviously when the bike is under some kind of load requiring higher RPMs to get it going). Any insight would be appreciated. Happy Holidays.

[Mr_Ed]

I'm a little confused by the title of your post compared against the text of your post. Are you talking about engine knock or are you talking about the bike somehow jumping out of first and into neutral?

[T__]

Rob, what type of knock you getting? Spark knock,, engine rattle,, gear rattle,, combustion knock,, other?.

 

Twisty

 

[Rob F.]

From a stop, my bike is in 1st gear. As I roll on the throttle, not more than 3K RPMs, and let the clutch out, I'll hear the engine knock sometimes. From what I can tell, it might be happening if the RPMs are too low. It is a knock coming from the engine. It sounds like a few clunks. Hope this helps but feel free to ask more questions.

[T__]

From a stop, my bike is in 1st gear. As I roll on the throttle, not more than 3K RPMs, and let the clutch out, I'll hear the engine knock sometimes. From what I can tell, it might be happening if the RPMs are too low. It is a knock coming from the engine. It sounds like a few clunks. Hope this helps but feel free to ask more questions.

 

 

Rob, without you being more specific on the type of knock it makes we really can’t offer you much in the way of being normal..

 

The 1200 BMW boxer engine runs fairly high compression,, somewhat decent cam profile,, lots of chains & guide ramps in the engine & now also has a gear set to drive the balance shaft so if you lug the engine it can rattle & knock.. The trans can also knock & rattle a little if you lug the engine & force high peak combustion pulses in the drive train..

 

If you doubt your engine integrity either have your local dealer tec ride it or go ride a BMW demo bike under the same launch technique..

 

Twisty

 

[Mr_Ed]

So you have the clutch fully engaged and you're running 3K revs or less and there's an engine knocking sound?

 

Your guess that your revs might be a little low may be on target. Do you have ready access to a dealership? Maybe you could test ride another 08RT and see if you can duplicate the same sound on another bike.

[Rob F.]

Thanks guys for the tips. My bike is due for its 6K service so I'll have the shop check it out.

[Deek]

Thanks guys for the tips. My bike is due for its 6K service so I'll have the shop check it out.

 

Be sure to post what they find. I'm curious.

[motorbob]

Rob,

You are lugging the engine. The Boxer engine doesn't like low revs. Doesn't really like high revs either.

I have both a 08 RT and 07 GT. The GT doesn't care about RPM, simply give it gas and it goes no matter the gear or RPM.

The RT is more work. You must keep the revs over 3K or it will knock. Not spark knock or gears rattling simply telling you to run the engine in its preferred range of 3-5K.

I learned my lesson on my previous RT (06) Used to Japanese inline and V4s I was using low revs and experienced the knock you are referring to.

Last summer I rented a RT for a day did 600 mi, kept the engine above 3K and liked it so much I bought another one.

My SO hates being a passenger on my GT but just love the comfort of the RT. The comfort, riding position, wind management are magic.

 

Will have a almost brand new K1200GT with 11 000 km up for sale next spring.

[hexairheadbeemerguy]

I have +25 years experience riding air & now hex heads and my bet is what you are hearing is the dry clutch rattling. A wet clutch will not rattle this way, my '73 2002 using a dry clutch made the same noises. My '83RT is less likely to rattle than my '07RT but the '83 is only 8:1 ratio vs 12:1 on the '07. My '07 needs more throttle, i.e. more rpms from a dead stop or rattles like hell; the '07 has 27K kms on it and not problem of any kind.

[Dave_in_TX]

I have no knock with my 07 RT and I rarely rev it to more than 2000 rpm when starting out from a dead stop. As the clutch is engaging, rpms are usually about 1500.