BnkrBill Posted January 31, 2009 #1 Posted January 31, 2009 Ok, here's the deal. I was very glad when I found there was a site for Yamaha Ventures Today I purchased an 88 Venture Royale. It is in what appears to be very good shape, however I noticed that it would not rev up. It will go well out of the hole but will not let the rpm's get very high. You need to shift sooner than usual or it will bog down. Max speed as it is right now is about 45 mph. At a standstill if you give it throttle it will only rev up a little and then it stutters. I pulled the parts off to look down the throat of the carbs and as I give it throttle all 4 sleeves appear to shutter after moving only a little. Since the rest of the bike was excellent, the transmission felt good and the engine appears to run well I thought I would take a chance on it being something relatively simple. Any ideas? or do I have a real nice coat rack in may garage? Thanks for any help you can give me BnkrBill
pegscraper Posted January 31, 2009 #2 Posted January 31, 2009 Do the throttle slides open up freely by hand?
BnkrBill Posted January 31, 2009 Author #3 Posted January 31, 2009 How would I go about determining that? If I use the throttle they only move a little bit. Bnkrbill
skydoc_17 Posted January 31, 2009 #4 Posted January 31, 2009 Hey Bill, Welcome to the VentureRider.Org Site! There is a great bunch of people here and you will enjoy the help and might have a few laughs in the process. OK down to business, You didn't mention if the scoot had been sitting or not, but what you have described is pretty much the way most first gens. come to their new owners. I usually change out all of the "perishable" items when I get a new used bike just so I know where I stand. But before I get ahead of myself lets take this in some sort of order. 1) drain fuel and replace with fresh fuel. 2)drain bowls on carbs. 3) add Seafoam to the gas tank. red and white can @ advance auto, autozone, some walmarts, Some say 1/2 can per tank I am a bit more generous 1 can per tank the first time, Run until up to operating temp. then let sit overnight, then if it gets better try to ride it hard for the entire tank, you are cleaning out the fuel system. 4)If you luck out and it starts running better, throw in a new set of plugs. 5)I would look at the fuel filter next and replace. (PM me for location and instructions) By the way first gens. don't like to run much above idle with the air filter cover off, FYI. 6)If you are seeing more improvement, I would think about an air filter next, I use the K&N washable but a new stock one is just fine. This is where my 87' VR "hit the wall" I could not get it to run any better, it was a runner but not perfect. 7) At this point I had to replace the carb. diaphragms, I got just the rubber diaphragm off of Ebay for a very good price. This took my scoot to a new level and it is now a daily driver. There are other "gremlins" that could be causing your problems but until you take care of the simple stuff you will just be "throwing parts" at your scoot. ALL of the things I have mentioned here can be done yourself, and for the cost of the parts only you can solve about 90% of the problems the every new owner of a used first gen. goes thru. If you have more questions, continue to post and the members will be more than happy to walk you thru any repairs you need to make. If you are not an open forum kinda' guy, send me a PM and if I don't know the answer, I will find out for you. Again welcome to the VR.Org site! Earl and Jean
bobcat Posted January 31, 2009 #5 Posted January 31, 2009 Earl covered it well....I'd replaced the plugs first, add a can of seafoam, check the air filter then replace the fuel filter before I dug into the carbs...I like to eliminate the easy and cheaper things first....Plugs, seafoam and fuel filter should cost about $20-$25 bucks...(fuel filter located under and behind left saddle bag area..... Good Luck
WilCruise Posted January 31, 2009 #6 Posted January 31, 2009 Yup, That's the best way to start. Some of us like to go highly concentrated on the seafoam with a new aquisition to get it cleaned out. Search on seafoam and you'll find lots of discussion about it. After draining all old fuel as suggested, run the tank down to reserve with some fresh fuel then throw in a whole can of seafoam. Run it enough to get that into the carbs (it'll sputter & smoke a bit but should still run). Let that sit for 24-36 hours or so, run it a bit more then top up the tank. Once that tank is gone you'll usually be in much better shape. If not then it's time to do more tinkering. Good luck and welcome aboard.
Squidley Posted January 31, 2009 #7 Posted January 31, 2009 All good advice, Seafoam can cure a LOT of problems on the Venture. Something I aways do with and older Venture that is running bad is ride it like you hate it once you put the seafoam in. All the Jap bikes that I have owned seem to run best when you ride them like that once in a while. I will say to do a complete tune up on the bike, Plugs, Wires, Caps, have a good start point for all your maintenance records. Welcome to the club and if you have any question never hesitate to ask, there are no dumb questions here
Black Owl Posted January 31, 2009 #8 Posted January 31, 2009 And don't forget to sync and tune the carbs,,,,
GaryZ Posted January 31, 2009 #9 Posted January 31, 2009 The bike starts, idles and runs fine in the low speed circuit but will not run at higher RPM. Your description suggests one or more broken carb diaphragms. The slide(s) won't lift and intake air/fuel is limited.
Yammer Dan Posted January 31, 2009 #10 Posted January 31, 2009 Sea-Foam and plugs first and then look at Diaphragms and filter. Filter on top of swingarm on left side. Kind of hard to reach. It is best to replace it when you change tires but you can do it when needed. All good advice here. Welcome, and you will enjoy that scoot. Built way ahead of its time. Air ride and everything work OK?
pegscraper Posted January 31, 2009 #11 Posted January 31, 2009 (edited) How would I go about determining that? If I use the throttle they only move a little bit. Bnkrbill The engine doesn't need to be running. Stick your finger down in the carbs and see if the slides move or if they're stuck. If they won't open up all the way, the bike won't be able to rev up much at all. If they're good, why I'm sure the the seafoam will be your magic genie in a bottle. It fixes everything, no wrenches needed. Edited January 31, 2009 by pegscraper
jasonm. Posted January 31, 2009 #12 Posted January 31, 2009 The slides/diaphragm assys are the likely issue. With one bad, you'll get a break up or bogg up high in the revs . If 2 or more are bad you will have that sluggish feeling you describe. My '83 had the exact issue. It was the slide assys. The rubber developes holes and loose the ability to open up as designed. The price on these used to be below $50 each. I do not know what they go for now in todays whacky economy ? Some have tried to repair the holes. But seriously, what really survives in a gas fume environment and is flexible?...nothing. Do not use a silicone RTV! As they clearly warn against this usage on the package. Replace them, but you need a special hollow torx bit to get one cap screw out. Another slim chance, It is also possible a jet or 2 is clogged. Like I said , my '83 did the exact thing.
mbrood Posted January 31, 2009 #13 Posted January 31, 2009 This could also a symptom of a bad boost sensor.
lonestarmedic Posted January 31, 2009 #14 Posted January 31, 2009 If you need diaphragms, try this guy. As long as the slides are smooth. http://cgi.ebay.com/ebaymotors/DIAPHRAGM-YAMAHA-XV535-VIRAGO-XVZ12-XVZ13-VENTURE-ROYAL_W0QQitemZ280306841143QQihZ018QQcategoryZ35597QQssPageNameZWDVWQQrdZ1QQcmdZViewItem JB
Guest mtruitt_1971 Posted January 31, 2009 #15 Posted January 31, 2009 another option you may consider is that the boots are cracked or there is an air leak somewhere, i had the same problem once on a yamaha xj650 the problem was that the airbox made it a sealed unit and without it the enging sucked in too much air and not enough gas, just another option to consider, also if you have a vaccum leak it may cause the same effect TEST: start engine and let idle , open up your propane torch so the gas is flowing out the tip (DO NOT LIGHT THE GAS) and move tip all around, if idle picks up you have a leak in that general area.
BnkrBill Posted January 31, 2009 Author #16 Posted January 31, 2009 Thanks for all great ideas. I will get the seafoam and give that a whirl. I checked the choke and relased the cable where it hooks up. It appears that the choke is stuck. Could it still run at low rmp with the choke stuck open? And here's a real dumb one. How the heck do I get the seat off? Thanks Bnkrbill
MidlifeVenture Posted February 1, 2009 #17 Posted February 1, 2009 http://www.venturerider.org/forum/showthread.php?t=23472&highlight=seat+removal Look here.
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