Guest eamann Posted March 8, 2012 Share Posted March 8, 2012 I am finally in the final stages of getting my carburetors set for riding and need to sync them. The local dealer quoted about $250 to do this for me, which is way out of my budget. Can anyone give me a beginners guide to what I will need and how I sync the carbs on my '86 VF500F? I have no experience with this but need to learn. Thanks! Link to comment Share on other sites More sharing options...
Member Contributer Chuckster Posted March 8, 2012 Member Contributer Share Posted March 8, 2012 Buy yourself a Morgan Carbtune, do it yourself and learn about your bike at the same time. http://www.carbtune.com/ Chuck Link to comment Share on other sites More sharing options...
Guest Posted March 8, 2012 Share Posted March 8, 2012 Sounds great. I'll look into the tool. If you can give me a shove in the right direction as to the process as well that would be great! Link to comment Share on other sites More sharing options...
Member Contributer Chuckster Posted March 8, 2012 Member Contributer Share Posted March 8, 2012 I think the site has directions on it. If not, let me know and I'll copy mine and send them to you. Chuck Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted March 8, 2012 Member Contributer Share Posted March 8, 2012 Save yourself $50 and build one yourself. Think mine costed me $15 from home depot and works just as well. There's a thread buried somewhere on how to make one. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted March 8, 2012 Member Contributer Share Posted March 8, 2012 http://www.vfrdiscussion.com/forum/index.php/topic/67423-how-to-build-a-monometer-and-how-to-perform-a-carb-sync/page__p__788707__hl__manometer__fromsearch__1#entry788707 Link to comment Share on other sites More sharing options...
Guest Posted March 8, 2012 Share Posted March 8, 2012 Perfect! What kind of adapters am I going to need for the '86 vf500? I will go to the store and pick up the stuff as soon as I figure that out. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted March 8, 2012 Member Contributer Share Posted March 8, 2012 adaptors? The tubing should fit right up to the vacuum port, if that's what you mean. Link to comment Share on other sites More sharing options...
Guest Posted March 8, 2012 Share Posted March 8, 2012 Yes but there is only one vacuum port on my bike. The rest are covered with screws. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted March 11, 2012 Member Contributer Share Posted March 11, 2012 Yes but there is only one vacuum port on my bike. The rest are covered with screws. I'm going to need pics. You have one vacuum port for EACH carb (4 total). They should have a little black boot over them. That's what you're talking about right? And then you have three screws to adjust the carbs, as carb #1 is the base the rest have to work off of. Link to comment Share on other sites More sharing options...
Guest Posted March 13, 2012 Share Posted March 13, 2012 Ok. I will give you pictures tomorrow. I found the nipples on a website and have ordered them already You might be a bit confused because the '86 carbs are different than the '84-'85 versions. The vacuum ports are not on the carburetors themselves but instead, are drilled into the intake part of the engine, below the carbs. Three of these are covered by screws and the other is covered by a brass nipple that, when the tank was vacuum controlled, was used to suck gas out of the tank. Link to comment Share on other sites More sharing options...
VFRBert Posted March 14, 2012 Share Posted March 14, 2012 Before you start the operation, get this little tool. You won't get burned fingers anymore while adjusting the synchronisation screws. Shrink a piece of tubing (pvc wil get soft after carefully heating, put it on the screwdriver head and let it cool down) pvc shrinks during cooling down and the tube wil thighten itsself aroud the screwdriver head) use an extension and ready you are Link to comment Share on other sites More sharing options...
Guest Posted March 18, 2012 Share Posted March 18, 2012 DSC01128 by eamann66, on Flickr Ok so the manometer is finally complete with a few adapters from Carbtune. I tried to test it out today though and ran into an issue. It may be that my carbs are just that far off but every time I turn on the engine, two of the tubes go way up in a few seconds so I have to turn off the bike. Could this be because I don't have the tubes attached correctly? Anyone know what to do about that? Or is it that the manometer might be leaking? I made sure to seal all of the gaps pretty tight with glue and duct tape. Any ideas? Link to comment Share on other sites More sharing options...
Member Contributer Sparrow75 Posted March 19, 2012 Member Contributer Share Posted March 19, 2012 Sounds like those two carbs are the ones that are out of sync with the rest. Try adjusting those two carbs then restarting. If out of sync repeat adjustment, until they are all close together. I sync my carbs one at a time, adjusting to match the reference carb (# 1 or #4). Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2012 Share Posted March 19, 2012 How much should I adjust them with the engine off? Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2012 Share Posted March 19, 2012 I'm looking into this whole sync thing myself, my bike may need it as well. Not gonna pay a cpl hundred when I can do it myself. If I was to adjust them with the motor off I'd set them to factory specs from the get go and go from there. Definitely not an expert here though lol. It seems like an easy process from what I'm reading so far... Link to comment Share on other sites More sharing options...
Member Contributer Chuckster Posted March 19, 2012 Member Contributer Share Posted March 19, 2012 How much should I adjust them with the engine off? You have to make adjustments with the motor running. Chuck Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2012 Share Posted March 19, 2012 The only issue with that is that the oil seems like it is going to get sucked into the engine. Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2012 Share Posted March 19, 2012 The only issue with that is that the oil seems like it is going to get sucked into the engine. Just gotta have those long tubes and be ready to hit the kill switch. Use a thicker oil in the tubes to slow it down a bit as well. If it's that bad I'd set the pilot screws to factory specs as well as the idle then start from there. Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted March 19, 2012 Member Contributer Share Posted March 19, 2012 How much should I adjust them with the engine off? You have to make adjustments with the motor running. Chuck Incorrect. You can make adjustments while the engine is off. So you are going to want to make adjustments on those two carbs while the engine is off to get them to a point where it's not going to suck the oil in. Just beware that on start some lines will jump up but then settle down a bit. Then you can leave the engine running and continue the sync. The only reason you need the engine running is because you need live feedback on how your adjustments affect the sync. Link to comment Share on other sites More sharing options...
VFRBert Posted March 19, 2012 Share Posted March 19, 2012 You need to connect all the hoses, and use some kind of buffer. I took this picture of the dutch VFROC forum, this is a working home made synchroniser. As a buffer they use 4 jam jars. If the engine sucks to hard on the line's, the fluid is sucked into the jars and not into the engine. The lines are glued airtight into the lids. How harder the engine sucks on a line, the higher the fluid rises, youre are not measuring vacuum opressure, only the difference in vacuum between the four cilinders Bert Link to comment Share on other sites More sharing options...
Member Contributer jeremy77 Posted March 19, 2012 Member Contributer Share Posted March 19, 2012 So... I understand DIY stuff is fun but I have trouble seeing the benefit of going to trouble and expense of making one of these when you can buy one for $90. I know $90 isn't nothing, but it seems like a lot of parts and time is required for the DIY version... and how do you ensure it's accuacy. Am I missing something? http://www.amazon.com/Motion-Pro-SyncPRO-Carburetor-Accessories/dp/B0058AFZGQ/ref=sr_1_28?ie=UTF8&qid=1332171435&sr=8-28 Link to comment Share on other sites More sharing options...
Guest Posted March 19, 2012 Share Posted March 19, 2012 Well, as a college student, every penny saved helps. And in reality, it only took me about 15 minutes to put the whole contraption together, so if it does work correctly, it's definitely worth it. The only reason it wouldn't work is if there is an air leak in the bottom of the thing by the connectors. Not a difficult issue to fix. Link to comment Share on other sites More sharing options...
Member Contributer Sparrow75 Posted March 19, 2012 Member Contributer Share Posted March 19, 2012 Eamann, I suspect your manometer is not leaking air...that is if the fluid in two of the four lines go up while the other two go down by the same amount. If it is leaking at the bleeder screw in the cylinder head then that may be part of the problem. In your pictures the fluid in your manometer looks like if might be clean motor oil? I used ATF because it is thicker and will rise and fall a bit slower that a thinner fluid...and its easy to see. Did you use a thin strip of paper to bench synchronize the carb throttle plates. Make sure that the drag on the strip of paper in the middle of the throttle opening (near the small hole when closed) on the reference carb was the same as on the other carb bodies, when throttles are closed. This was important to set the carb throttle sync close to each other so that on start up it is easier to dial the sync in further with the manometer attached. If you handle the carb linkages roughly on install for some reason, then your sync may be significantly off. When syncing carbs I find that on my 750F a quarter turn can make a big difference. Revving to higher rpms shows that a carb that is lower on idle may be slightly higher at 3000 - 5000 rpm. I just try to have less than 2 inches of ATF (not sure how many millimeters of mercury that would be) difference between carbs at 5000 rpm. Perhaps other might comment on this, but if the bleeder screw has a large hole then might be harder to sync as the fluid will be drawn up or down to quickly. As I understand, if the holes are smaller (and the same diameter of course) then the manometer will be less jumpy (ie. sensitive). Link to comment Share on other sites More sharing options...
Guest Posted March 20, 2012 Share Posted March 20, 2012 Eamann, I suspect your manometer is not leaking air...that is if the fluid in two of the four lines go up while the other two go down by the same amount. If it is leaking at the bleeder screw in the cylinder head then that may be part of the problem. In your pictures the fluid in your manometer looks like if might be clean motor oil? I used ATF because it is thicker and will rise and fall a bit slower that a thinner fluid...and its easy to see. Did you use a thin strip of paper to bench synchronize the carb throttle plates. Make sure that the drag on the strip of paper in the middle of the throttle opening (near the small hole when closed) on the reference carb was the same as on the other carb bodies, when throttles are closed. This was important to set the carb throttle sync close to each other so that on start up it is easier to dial the sync in further with the manometer attached. If you handle the carb linkages roughly on install for some reason, then your sync may be significantly off. When syncing carbs I find that on my 750F a quarter turn can make a big difference. Revving to higher rpms shows that a carb that is lower on idle may be slightly higher at 3000 - 5000 rpm. I just try to have less than 2 inches of ATF (not sure how many millimeters of mercury that would be) difference between carbs at 5000 rpm. Perhaps other might comment on this, but if the bleeder screw has a large hole then might be harder to sync as the fluid will be drawn up or down to quickly. As I understand, if the holes are smaller (and the same diameter of course) then the manometer will be less jumpy (ie. sensitive). Yes I am using motor oil. I will change that out to something a little thicker. I did bench sync the carbs and the pilot jets are all 2 and 1/2 turns out which is the factory setting. Air could be leaking between the bleeder nipple I suppose. I will give that a shot tomorrow. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.