Member Contributer veefer2010 Posted March 28, 2015 Member Contributer Share Posted March 28, 2015 "You see but you do not observe," as Sherlock Holmes would surely have said to me. I've become quite expert at adjusting the VFR800 starter valves - again and again - seeing the vacuum gauges but not observing what they were telling me.. The Honda book says the starter valve vacuum difference is 20mm. My gauges told me that the non-adjustable SV valve (#4) was actually 10mm but I had been ignoring the reading on the gauge and setting the other three valves the same as #4, i.e. all four SVs to 10mm. It turns out that #4 is adjustable and quite easily so. It even has the same little locating detents as the other three SVs. SV #4 has a couple of flat sides on it and a 3/8" open-end wrench fits perfectly. I wound it out and then out some more until the gauge read 20 mm. (I calibrated all four gauges using my brake-bleeder vacuum tool first). Then I did the SV adjustment for the 5th time but to 20 mm. Finally, smooth as silk - just like a real motorcycle; no more snatchy throttle. My bike is stock standard. Stock pipes, no mods to PAIR Valves or O2 sensors and all anti-pollution gear is connected and working, No Power Commander, everything by the book. Ciao Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted March 28, 2015 Member Contributer Share Posted March 28, 2015 +1 had the same thing on my 03 . Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted March 28, 2015 Member Contributer Share Posted March 28, 2015 Well as the cheap gauges pictured, which I also use, are not great quality, I only use 2. First I sync both to read exactly the same on the reference cylinder, then l leave one on reference & move the other to the other 3 cylinders in turn, until the throttle is super smooth, then return to the reference to confirm its still reading exactly. Best way I've found. Link to comment Share on other sites More sharing options...
Member Contributer Cogswell Posted March 28, 2015 Member Contributer Share Posted March 28, 2015 Thanks for posting. I'm keeping this for reference when I adjust mine. Link to comment Share on other sites More sharing options...
Member Contributer FJ12Ryder Posted March 28, 2015 Member Contributer Share Posted March 28, 2015 I've put this off forever, I really need to get my a$$ in gear and get it done. Link to comment Share on other sites More sharing options...
choco Posted March 28, 2015 Share Posted March 28, 2015 Snatchy low end throttle is my only real complaint on this engine, 2004 Link to comment Share on other sites More sharing options...
Auspanglish Posted March 28, 2015 Share Posted March 28, 2015 Very interesting Link to comment Share on other sites More sharing options...
Member Contributer veefer2010 Posted March 28, 2015 Author Member Contributer Share Posted March 28, 2015 Snatchy low end throttle is my only real complaint on this engine, 2004 That was my biggest complaint too. Over the years I've had a Blackbird, a Fireblade 929 and a CBR600RR and none had a snatchy throttle like the VFR800 - they all worked fine (all with anti-pollution stuff connected). I hated the VFR fuelling so much that I was very close to selling the bike but now I think I'll keep it. Ciao Link to comment Share on other sites More sharing options...
Member Contributer Grum Posted February 25, 2016 Member Contributer Share Posted February 25, 2016 Hi veefer2010. I am a bit confused by your posting. Firstly, the 20mmHg difference is an allowable tolerance between the setting of all three starter valves referenced to number 4. Secondly, assume you mean that your number 4 reference starter valve was only 100mmHg (not 10mmHg). 100mmHg seems very low and is about half the vacuum I have experienced for number 4 (see attached photos). Suggest this has been previously tampered with. Thirdly, assume you have set the reference valve number 4 to 200mmHg. Fortunately, this is a ball park figure which could work well to balance the others to, as the manual mentions that the MAP (Manifold Absolute Pressure) at Idle is between 200 - 250mmHg Searching through the service manual there appears to be no vacuum value stated for the Reference Starter Valve - and possibly for good reason as it is factory set and no doubt the reading would vary depending on your local conditions being, temperature, barometric pressure and altitude. Number 4 should not be messed with and the others balanced to it at an idle speed of 1200rpm and at normal operating temperature. In your case it appears someone has previously messed with it. Attached are two post adjustments done on a 2007 and 2009 VFR - note the difference between the reference number 4 valves for both bikes which were NOT adjusted, first bike 200mmHg and second bike 240mmHg. Also the 20mmHg allowable difference tolerance is shown between two major graduations, so both bikes are well within spec. Both bikes had no fuelling issues in the low throttle band after adjustment. Hope this clears the air a bit. Glad you got your bike working well. Cheers. Grum Link to comment Share on other sites More sharing options...
Knight Posted February 25, 2016 Share Posted February 25, 2016 Grom this thread is older but you sucked me in anyway. Can't speak for the 7th gen but on prior bikes the 4th cylinder was glued or locked in place. If they do the same on the 7th gen then the fact that it is movable is support for what Grum said that it had been altered. To Grom's point note that the tolerance is 20 mm but your gauge in mm has an extra zero so your absolute setting is 20 cm. So the setting is 20 cm +- 20mm. Maybe you just mis-typed which is easy to do, but I thought I'd point it out because I originally had a similar misunderstanding. Link to comment Share on other sites More sharing options...
Member Contributer MaxSwell Posted February 26, 2016 Member Contributer Share Posted February 26, 2016 Does this apply to fifth gens? My throttle is snacthy at low rpms. I've never done anything with starter valves in about 140,000 miles of fifth gens. Link to comment Share on other sites More sharing options...
Member Contributer Grum Posted February 26, 2016 Member Contributer Share Posted February 26, 2016 Does this apply to fifth gens? My throttle is snacthy at low rpms. I've never done anything with starter valves in about 140,000 miles of fifth gens. Hi MaxSwell. After 140,000 miles I would say a Starter Valve Synch is looooooooong overdue. Having it checked and adjusted could well sort out your low throttle issues as this is just the area where starter valve synch is critical, at the very low throttle opening range. Not sure on the procedure for a 5th. Gen. Cheers. Grum Link to comment Share on other sites More sharing options...
Knight Posted February 26, 2016 Share Posted February 26, 2016 Yes make sure and use the 5th gen manual. The 5th gen has staggered vacuums while the 6th gen has identical settings per cylinder. MaxSwell, I bet $1 that your bikes have had the idle adjusted, yes? As it ages the cylinder vacuums diverge from the spec and the idle gets rougher and goes down. The rider may begin stalling thinking that they aren't gassing it enough at the stoplight or that the idle is too low, and thus adjust the idle up. Once you tune the starter valves the idle will shoot up and you'll see when done the final step is adjusting the idle back down to 1200. The new idle is smoother and more powerful, much easier to tool around the parking lot with little or no throttle and partial clutch. And most if not all of the on/off behavior of the throttle will be gone. Yes, whatever problems are left can be corrected with fuel controllers. But tuning the bike is a critical first step. Speaking of which, if you have a Power Commander now, it may be over-fueling in order to compensate. I was able to tune my PC before I could get the starter valves tuned so I know. At 3700 RPMs, partial throttle, 35 mph, the engine shakes. Increase fuel in that area and the engine shake goes away. But the vacuum variance is still there and throttle response is still snatchy. Thus when the starter valves are tuned, the fuel should be re-adjusted, most likely leaned out in the partial throttle areas. Link to comment Share on other sites More sharing options...
Member Contributer MaxSwell Posted February 26, 2016 Member Contributer Share Posted February 26, 2016 Thanks Knight! My eyes have been opened. Yes I've adjusted idles in the past. Now I've got something critical to do to improve things. Is there a particular measuring device I should purchase? BTW: The 140,000+ miles were spread across five fifths. Only one, my first, had 100,000+ mi. Man! What a great piece of engineering! Link to comment Share on other sites More sharing options...
Member Contributer maxredline Posted February 27, 2016 Member Contributer Share Posted February 27, 2016 I am just about to tune my bike. Valves were spot on and I have removed the pair plumbing and flapper hose. Once I get it all buttoned up with new gaskets and plugs I will attempt my first sync with a PC 3 inplace. This is what I am waiting for from Amazon. I didnt want to go with the cheaper gauges, $194.38 CAN shipped Link to comment Share on other sites More sharing options...
Member Contributer MaxSwell Posted February 27, 2016 Member Contributer Share Posted February 27, 2016 Yikes! They are pretty proud of that tool. But I suppose one gets what they pay for. Thanks all. Link to comment Share on other sites More sharing options...
Knight Posted February 27, 2016 Share Posted February 27, 2016 Maxredline, would you mind adding to that post the make and model of that kit? Did you pick it over another similar item or were there few choices? The reason I ask, as I browse Amazon I don't see 4-gauge kits. I rely on mechanics for now, so others can chime in, but it seems the 4-column single manometers that some here use have a lot of negative feedback. They seem to be a real compromise over separate gauges. And at $100 for a 4-column vs. $200 for 4-gauges, the latter seems to be a no-brainer. No? Link to comment Share on other sites More sharing options...
Member Contributer RobF Posted February 28, 2016 Member Contributer Share Posted February 28, 2016 This is what I am waiting for from Amazon. I didnt want to go with the cheaper gauges, $194.38 CAN shipped Maxredline, would you mind adding to that post the make and model of that kit? Did you pick it over another similar item or were there few choices? The reason I ask, as I browse Amazon I don't see 4-gauge kits. I think maxredline is referring to this unit: http://www.amazon.com/dp/B004MSE9JO I've been contemplating doing the starter valve sync on my 6th gen. That's not a job I've ever done before. I eventually found similar units on Amazon by searching for "carburetor synchronizer" -- which surprised me since the 6th gen doesn't have, you know, like... carburetors. I guess the tool and underlying concepts are the same even though the hardware being inspected isn't. The things I learn reading VFRD! Link to comment Share on other sites More sharing options...
Knight Posted February 28, 2016 Share Posted February 28, 2016 This is what I am waiting for from Amazon. I didnt want to go with the cheaper gauges, $194.38 CAN shipped Maxredline, would you mind adding to that post the make and model of that kit? Did you pick it over another similar item or were there few choices? The reason I ask, as I browse Amazon I don't see 4-gauge kits. I think maxredline is referring to this unit: http://www.amazon.com/dp/B004MSE9JO Thank you very much. What a convoluted name they labelled this item with. The kit is $129.50 USD, which seems inexpensive, but once again I see very mixed reviews. Some things do not change. Sales and marketing people don't know that fuel injection is here, or that fuel injected vehicles have vacuum to adjust? These should be labelled "vacuum gauge", with some of the detail in the sub-header so people understand that they are sized and scaled for automotive systems. It is 2015. Our ability to process data is infinitely greater than just a decade ago. Cannot consumer goods be labelled better? Link to comment Share on other sites More sharing options...
Member Contributer maxredline Posted February 28, 2016 Member Contributer Share Posted February 28, 2016 Knight, I would consider the sync tubes if I could find glass with mercury at a reasonable price but I did not. I found tubes that were plastic that had fluid that would go bad within a year or that just required maintanence that I did not want to have to deal with in a tool. The guages I have bought first of all don't look cheap. They could very well be cheap but the reviews of people who bought them were postive including a mechanics shop. I really don't have much info on them but when I receive them in March I will post up for you. I found another place that sells them. Check out the page and look at the cheaper set....you decide 8) http://www.thealphamoto.com/motorcycles-tool-s/1814.htm Link to comment Share on other sites More sharing options...
AllWeather Posted February 29, 2016 Share Posted February 29, 2016 I have a set of the Carbtune vacuum gauges with the 4 tubes and the metal sliders and I also have access to a set of digital vacuum gauges and a set of motion pro mercury tubes ( no longer available to buy ) that my good mate owns as he has a workshop Now when we did a comparison with both sets attached to one bike via a "T" connector as on both #1's then both #2's connected and soon The readings were almost the same well within the allowable differences less than 2mmhg between the 2 sets of gauges We also tested the Carbtune the same way with a set of mercury gauges and same result So maybe I got lucky and got a good set but they have served me well and seem to be more than accurate than some would have you believe The secret to a good balance of carbs /starter valves / throttle bodies is patience ,a good airflow over the motor so the temp stays reasonably constant and allowing the motor to settle after a quick blip of the throttle after making small adjustments I make some money out of fixing bikes and general servicing and I get to see the mess people make when they don't know how to do the job they are attempting or how to use the tools .........It can be a real eye opener Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted February 29, 2016 Member Contributer Share Posted February 29, 2016 You could also go the DIY route and build one for $15 that will be just as good. Link to comment Share on other sites More sharing options...
Member Contributer MaxSwell Posted February 29, 2016 Member Contributer Share Posted February 29, 2016 You could also go the DIY route and build one for $15 that will be just as good. How about a description? Link to comment Share on other sites More sharing options...
Knight Posted February 29, 2016 Share Posted February 29, 2016 You could also go the DIY route and build one for $15 that will be just as good. How about a description? Here are a couple discussions: http://www.vfrdiscussion.com/forum/index.php/topic/16200-homemade-manometer/ http://vfrworld.com/forums/showthread.php/37472-Can-anyone-recommend-a-good-CHEAP-manometer Link to comment Share on other sites More sharing options...
Member Contributer Terry Posted February 29, 2016 Member Contributer Share Posted February 29, 2016 I bought the MotionPro SyncPro which is a manometer design but using a non-mercury fluid, and this has served me well on my 5th Gen and VTR1000F for the last two years. I've had no issue with fluid loss, and I do like the calibration step that ensures all tubes are balanced before starting. My only niggle is that the scale is not mm mercury, just evenly spaced markings. For a synch where you want all cylinders equal, that's fine, but for the 5th gen that calls for staggered vacuums it is not obvious how much one should stagger the readings by. I hooked up a vacuum gauge from my vacuum brake bleeder (which is a marked in mm Hg) and deduced that the markings on the SyncPro are reasonably close to 10mm Hg. Link to comment Share on other sites More sharing options...
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