Great tutorial, and the best part is you survived, and didn't gas yourself by running your bike inside a closed garage.

Thank you, just thank you... I watched your video many times before I decided to take the plunge and I sync'd my starter valves yesterday. What a difference it has made! I used a Morgan Carbtune but the principle is the same but getting the hoses on & off that 4 way vacuum hose thingy was a ball ache! Would have never attempted it without this, so again, THANK YOU!

i just want to thank you for this video! I had SOOO much problems with my VFR800 starting cold and running rough when cold. NEVER i would i thing of this "flaper valve vacum hose" that was aperently loose ! Cylinder 2 was colder than the rest and i could not find error. Your video saved me !! THANK YOU!!! you got subscriber ! and i am watching all your videos !

Very clear explanations of how this job is done. Thanks.

Great vid mate. Thank you for making it, explaining it clearly and precisely and finally sharing it with us!

Bloody awesome, concise and to the point, like your style

Good for all to know this difference between model years... thx for confirming!

Exhaust note sounds awesome.

Thank's mate, good video. I'm to friggin old to do that sort of stuff, but good to know when I take it to the shop (No, not a Honda Stealership). A lot of forums talk about getting this done, now I know.

Kal, thanks for another clear explanation without extra fluff, straight to the point. Can I ask you this: My Gen 6 will idle normally, meaning that the starter valves are functioning normally, can I then assume that my injectors are also functioning normally ? and that the reason as soon as I twist the throttle, even minutely, (on the stand in neutral), the engine dies, is NOT related to blocked injectors, but some other item in the fuel delivery chain.

Excellent walk through.

Hey man great vid thanks for the share. I will say that is one dirty air box, there is all kinds of crap in there!

Mileage changes won't be caused by starter valves being out of sync. At most they affect driveability from a closed throttle. Since your bike is a 2002, I'd check your Fuel Pressure Regulator for leaks, as it's happened to quite a few bikes from that era.

Good video. It's almost identical to the ST1300. I noticed the inside of your air box seemed dirty, perhaps it's not sealed up?

Hey Kal... Auspanyol here... the Worskshop Manual says nothing about unplugging the MAP Sensor electrical connector... I didn't and got excellent results... either way the thing is no longer connected to the starter valves via the 5-way vaccum-line connector so it isn't receiving and info vía that tube...

Salve, scusa un informazione, come riferimento sincronizzazione devo prendere cilindro numero 1? Qual'è il cilindro numero 1? Dove si trova? Anteriori dx o sx? Posteriore dx o sx ? Ultima cosa gentilmente i manometri a quanto devono stare, ho una Honda VFR VTEC 800 del 2002, Puoi aiutarmi per favore? 🙏 Grazie mille distinti saluti

Very informative tutorial. Thank you. If I understood you correctly you left the flapper valve as OEM. Can you explain why please?

Hey Kal. Nice that there is someone like you to help out rookies like me. I just bought the Carbtune device, and is about to do my first injection sync on my VFR 800 VTEC. Is the starter valve sync the ONLY thing I need two do in regards to the syncronization of my throttle bodies?

Thumbs up for doing such informative videos!

The 98-01 Service Manual states to set #3 20 mmhg lower than #1 and set the #4 10 mmhg lower than #1, then confirm idle speed still 1200 rpm +/- 100rpm. Did you not do this for some reason? Did it really change to all at same vacuum from my generation to yours? Better check!

The best thing I found to hold the take up and is more stable is a plastic spray squeegee for an automobile.

'06 Gen 6 VFR 800i , I'm trying to find a problem that just when i crack the throttle off idle i'm getting a popping sound from somewhere in the throttle body. I've stripped it all down to check the sync but havnt started it yet trying to make sure i'm good to go so i'm watching videos on how to do it. Just wondering if its something anyone here has heard before, it seems to create a minor stumble also.

The 2002 onwards bikes do not use the uneven vacuum readings. All intakes need to be within 20mm Hg of cylinder #4 on these model bikes.

Could be the starter valves or possibly your fast idle wax unit isn't adjusted far out enough. A good way to test is to crack the throttle a tiny (and I mean *tiny*) bit the next time you try a cold start. If the bike fires right up with a slightly open throttle it means the bike wants more air. When the bike eventually starts cold - does it hold a high idle (above 1,500rpm) or does it want to stall until it warms up?

Where can I get the brass fittings that go into the vacuum lines? I have to sync my starter valves and I would love something permanent like that.

I need your help . On my 04 vfr , that bike has done 54000 kms , I decided to change the cam chain a cam tensioner , I changed them to new and set the timing perfectly as per manual , but not the left front cylinder is misfiring a bit .. can you help me out with some guidance .. what can be potential reason

Hi Mate, this may be a dumb question but can you explain why you needed to synchronise the starter valves? i just want to know the symptoms in case if this happens to me. i am learning hence the question. i have 2004 VFR800.

Are the throttle butterfly valves balanced or are they fixed on these? I understand why honda made the idle speed adjuster/ fast idle work like this rather than the traditional adjustable throttle stop, it is so that the throttle position sensor doesn't need adjusting whenever the idle speed is altered but why four individual valves? once the main throttle body assembly is balanced a single air bleed valve would have sufficed. I'm assuming that you would need to temporarily blank each of the four fast idle valve pipes before balancing the throttle bodies, which presumably would choke the engine of air meaning you then need to either adjust the fixed stop on the linkage or shim it somehow to get the bike to idle (so as not to disturb the factory setting and throttle position sensor) I feel it would be beneficial to balance the butterfly valves first THEN balance the fast idle valve, i've seen plenty of people balance the idle valves but noone balancing the actual throttle linkage/ butterflies.

Thanks for doing a great job with this video. I am about to do a sync on the ST1300,,, and I recognise that the throttle bodies are almost the same,,, just turned 90 degrees. I am just curious,, about the mentioned "flapper valve". It looks like a mod, that might be particular to VFR's ? What is the concept there ?? cheers,, Alan

Thank you for this video Kaldek. But what if a previous owner did change the number 4 starter valve? The number 4 can be adjusted the same way as the others. How would you set the number 4 back to the factory setting? I have searched and searched for this information. After doing the synch, I now have surging at SLOW speed and there is a small hesitation just before the vtec engages. This is a 2007 VFR. Please help. Jeffrey

one question on a 1998 honda vfr 800cc is fuel injection,yes or no and yes way it has a trottle cable advise please thanks

Do I plug the MAF vacuum

@Auspanyol Eh? Where do you have it connected if it's not via the 5-way?

hey man I did the pair valve flapper and snorkel mod and now my bike takes about 20 seconds to start on cold. and it's random sometimes when cold it will start right back up. I reconnected the pair valve cause I thought that was the only thing it could be

Sorry to bother you again but in your video, the FI light is flashing a code. On my bike the FI light stays lit and never flashes. After putting everything thing back the FI light goes off when the engine is started but does not flash an error code. What does that mean?

The idle screw is difficult to move, is that precisely because the bike needs to warm up so that the idle wax unit loosens enough to allow idle adjustment from the idle screw?

@Rangerscott69 Yeah, I actually don't have any of those, believe it or not!

Great video. I've recently had an issue with my 2002 where there is a popping noise from one exhaust while at idle, and my MPG dropped to 28. Could this be caused by the starter valves being out of sync?

I want to know if you put a cap on the map sensor hose

All good that for your vid

I haven't pulled off that airbox from my 5th gen VFR800 yet, it has about 21k km on it. Does a 5th gen have this same stuff? Should I be looking towards same adjustment? It idles at around 1200.

hi mate, still got the vfr?

Luckily didn't have to remove airbox to adjust on the 5th gen with a digisync

Where did you get those dials? How much do they cost each?

@ 5:00 what is disconnected? I played it 5 times but I still didn't get it.

not going to to tell you how to the lift the tank, then you do, good start lol.

Could be the starter valves or possibly your fast idle wax unit isn't adjusted far out enough. A good way to test is to crack the throttle a tiny (and I mean *tiny*) bit the next time you try a cold start. If the bike fires right up with a slightly open throttle it means the bike wants more air. When the bike eventually starts cold - does it hold a high idle (above 1,500rpm) or does it want to stall until it warms up?