Author Topic: K5 DL650 Carburetor balancing / synchronisation (Read 1808 times)

graingerblaze · « **on:** July 14, 2019, 09:10:12 »

I have read through a number of topics but can't quite find my issue so hope someone here can help?

A few weeks ago my bike developed an annoying vibration. At first I suspected the usual culprits, chain tension, Givi engine bars, loose fittings, general alignment... all checked out fine as the bike vibed just as much when stripped back to just the fuel tank and seat

So I decided to book her in at a local garage to check the carbs where nicely balanced. A week later I go to collect and they hand me the keys and say no charge as we can't get them to balance. Apparently one of the carbs would just not adjust, so they suspect an issue with the carburetor.

I rode the bike home, now even more lumpy than before so not useable till this problem is fixed. I phoned my local dealer (C J Balls in Norwich) and they charge £100 for balancing but can't do anything for 3 weeks.

So I plan to strip the carbs out, clean and check everything looks OK myself. After I have reassembled I want to have a go at balancing the carbs, having never done this does anyone have any suggestions for a good carb balancer and issues to look out for?

kwackboy · « **Reply #1 on:** July 14, 2019, 09:31:45 »

If your wee is a k5 it should be fuel injection and not carburettor.
Balancing throttle bodies can be tricky as you need to run the bike and for this the tank has to be connected.
Look up posts for throttle synchronization , I'm sure it's been covered .

Have you checked engine mounts, Wheel balancing, Maybe ?

graingerblaze · « **Reply #2 on:** July 14, 2019, 09:43:49 »

Well that shows how much I know about my bike

It is indeed a K5 (2005) wee 650, surprised my local bike garage didn't notice that crucial point. The wheels are fine, its not speed related by engine RPM. For example if I pull the clutch in while the bike is vibing (around 5,000 rpm), it all goes lovely and smooth so its not the chain, wheels or any extras like engine bars as no change when removed.

I asked the garage to check the engine mounts which they assured me they did and all fine. I am now questioning that so may buy the special nut tool to double check the torque rating on them.

The bike idles lovely, but anything over 4,000 rpm and it starts to buzz. So when at motorway speeds (5k) my hands and feet and becoming numb, so I know something is out but not enough to trip an error code or cause misfires.

I will need a balancer now as the garage made the bike worse, whatever they did I need to put back just not sure the best way to achieve / varify that the bike is nicely balanced.

kwackboy · « **Reply #3 on:** July 14, 2019, 11:09:30 »

When you pull the clutch in @ 5k are you keeping the rpm the same ?

sirkitchalott · « **Reply #4 on:** July 14, 2019, 11:13:30 »

https://photos.app.goo.gl/rTaZp5mXtshtgfbQA

I don' know if your bike has the same set up as my K Vee, but I followed a youtube vid on throttle body sync, bikes so smooth now.

Just need a couple of jam jars and some model fuel line. I made my set up out of some RC model fuel tanks.

oslin · « **Reply #5 on:** July 14, 2019, 13:24:51 »

it is nothing like as complected as it sounds providing you have a separate fuel supply bottle and a vacuum or mercury level gunge and there is nothing wrong with the adjustments on the throttle body's which is unlikely but it can happen and if it does they will need freeing off first but you do have to take the tank off and the air filter to gain access to the adjustments and then with the engine at running temperature make the adjustments,
the purest will also say the valve clearance should be correct as well before you make any adjustments but if they are within tolerance that will be fine.

Ianmc · « **Reply #6 on:** July 14, 2019, 14:19:04 »

I balanced my 650K9 throttle bodies with the fuel tank up on the prop.It was quite easy,just make sure you speed the engine up a touch before balancing as it makes it more accurate.Also make sure the TPS is set up correctly,I ignored Suzuki’s instructions and got it as low as possible,it makes the transition from idle to open much smoother.I am assuming that this model has secondary throttles as you must make sure these are opening fully when you twist the throttle WITHOUT the engine running and with ignition on.Good luck.

graingerblaze · « **Reply #7 on:** July 14, 2019, 16:41:28 »

Thanks for all the replies. When moving, if I pull the clutch and drop the revs the bike rolls along super smooth. If I then keep the clutch in but wind the revs up to say 5k, the vibes come back.

I'm pretty sure it's engine related, because I can feel the vibes by just revving when stationary. Before someone says that v-twins for you, I have had V's for over two decades from many different manufacturers and none have ever caused me numbing.

I will strip the bike, clean and reassemble with everything that's meant to move free to do so. I like the simplicity of making a home made balancer, although I may cheat and buy something.... Any recommendations please?

Thanks everyone, will have a start tonight

sjrainsford · « **Reply #8 on:** July 14, 2019, 17:27:16 »

I’ve got a Morgan carb tune (2 channel one). Great piece of kit.

Gert · « **Reply #9 on:** July 15, 2019, 07:44:55 »

Have you read https://www.vstrom.info/forum/forum_files/VStrom650ThrottleBody.pdf?

Fritz · « **Reply #10 on:** July 15, 2019, 14:48:37 »

Quote removed

Top gear - had one (4 cylinder) for 30 odd years and used from 400/4 to all my BM twins, simple & excellent. Once purchased you'll have a friend for life

graingerblaze · « **Reply #11 on:** July 15, 2019, 16:02:23 »

Just ordered a 2 channel Morgan Carb tool, will see if it helps when I rebuild the throttle bodies

Fritz · « **Reply #12 on:** July 16, 2019, 13:04:08 »

Quote removed

You'll have an able friend for life...mind I've only used mine on carburetors so hope works on EFI in same way - assume so. Need to investigate this voodoo electrickery malarkey.

PS - Don't buy a four cylinder bike mind

Octave · « **Reply #13 on:** July 17, 2019, 10:35:36 »

Hello grangerblaze,
When you attempt this procedure, would you take a few photos of the screws you are adjusting. I looked at a few youtube videos but could not see "screw adjusting details"

Good luck and success to you.

Ianmc · « **Reply #14 on:** July 17, 2019, 18:48:02 »

Hello “Octave”,it is in the link that “Gert”posted lower down.

graingerblaze · « **Reply #15 on:** July 17, 2019, 21:47:04 »

Will do, starting the strip down and preparations tonight, hopefully find time tomorrow evening to have a go

Joe Rocket · « **Reply #16 on:** July 17, 2019, 22:19:10 »

Ooooh! Rather you than me........ can only wish you every encouragement and sucess!

graingerblaze · « **Reply #17 on:** July 18, 2019, 23:40:58 »

So much easier than I thought it would be, a few tiny turns of a screw and the vibes have gone! I got the gauges within 1Hg of each other so well within spec now, wish I had done this months ago.

According to the Morgan Carbtune manual, this should be done every 5k! I have done over 15k since I bought her last year, no idea how long since the previous owner had them checked (if ever).

I found the vacuum pipe from the front throttle to the IAP sensor damper was a bit past its sale date. It had gone solid and stiff so was probably leaking, now replaced with new hoses.

Some photos of the vacuum ports if of any help. The procedure Ian kindly sent me was perfect!!!

graingerblaze · « **Reply #18 on:** July 22, 2019, 16:35:13 »

A quick video of the throttle balanced, and which screw I adjusted if anyone needs to know.

Gassoon · « **Reply #19 on:** July 22, 2019, 19:54:02 »

Glad you are sorted, graingerblaze, and thanks for posting the video; the more resources available to help us fix our bikes, the better!