greg_in_london

Thanks esaffley. I got the bike back together last night. I hadn't expected to - reconnecting those throttle cables has always been a difficult fiddly bit I don't look forward to - especially without extremely good light, but with one of those LED head torches it was fine. I don't want to say how it's going yet as I seem to get a 'honeymoon' period after each change. Suffice to say that bench synching left them way off, but a quick balance improved matters, although one carb was still reluctant to run cleanly (possibly because it had been petrol-logged for a while). Either way, we're off for the weekend now and won't be near a TV, computer etc until Sunday, so I'll post how the Venture went then. After that I'll start putting together a log of different mileages/fuel consumptions and try and find a way for people to add to it, starting with mine nd Esaffley's figures.

Hi Gearhead - all the floats float quite happily in petrol, so I don't think any have gone porous. I'm being ultra careful checking all the float levels while still on the bench. I'm finding that a level to the top of the float (measured to the middle of the float - not the highest point) from the central needle jet part of the casting of 20.5mm gives a fuel level of about 17mm, whereas a height of 20mm is giving a float level of about 16mm. I'm measiring the level from the bottom of the meniscus (the bottom of the curve in the tube). I do find it difficult to measure the fuel/float level accurately, though. As a rule of thumb, this had the top of the float pretty much horizontal (tip from yamahaventureclub) on the first I did, but on the second the angle was slightly higher to get the right height. Don't know why - the pivot pin didn't look bent. mbrood - no I don't think that has been mentioned. Are you aware of it being an issue? It is quite some time since I looked at the timing, but when I did it was within the correct range. With the vacuum advance it was hard to know exactly what position/mark the fully advanced ignition would show at, though. If this was a factor with age, though, we would expect more bikes to have their mileage/consumption drop over time, which does not seem to be the case.

Hmmm - something I would have ordered if I'd known. Around the nozzle/needle jet there is an o-ring which is probably well worth changing. I've got plenty of o-rings, but these are unhelpfully narrow. If you did this make sure that you have four o-rings, inside diameter 8mm (or 7mm would do) by 1mm thick. I haven't got those, so I am trying to make do with 3.5 mm by 2mm thick, stretched over the jet, on the basis that when stretched to (more than) twice its diameter it will have the right cross section. If it works I'll say so, if not I'll have to tear them apart again and locate some skinny o-rings. Grrrr.

Hi Gearhead, no I've never changed the float needles before either, but I don't seem to get consistent results checking the float height and now I've got one carb flooding, so buying replacements seemed a way of eliminating one problem. If they don't arrive by tomorrow, I may have to put them back together, but with the float height set lower. I had been setting it to about 14mm as per the TDK, but for my model should be 16mm, which will give a bigger safety margin. That will be closer to how it was set before, when it was running better anyway. Esaffley, I'm not sure how many different models I have specs for, but could you let me know which model you have - I don't know if there was only one specification available in 1987. It seems likely, but in 1983-4 there were at least four ! What you get a 80-90 is as good or better than I ever got with conservative riding. What you get with slow riding some people probably don't even believe, so if we could check what your jetting is, or anything else that is different on your model, it could be useful for the rest of us.

I spoke to Andy at http://www.nrp-carbs.co.uk who unfortunately can't provide the nozzles at the moment, other than by ordering via Yamaha. He was of the view that the needles and nozzles/needle jets do not wear significantly on Ventures or V-Maxes and that is usually the soft bits - diaphragms, seals and o-rings that go first. Obviously some other people have been given different advice. My VR has just under 55,000 on the clock (the last twenty five-thirty with a sidecar attached). So far I've taken one of the cabs apart - I'd rather not risk mixing bits up and the float needles haven't arrived yet - and I can't see wear on the nozzle/needle jet. I'm going to sort out some magnification, but it doesn't look oval to my eyes. When I block the end, blow through the hole on the side and slide needle in and out, air flows fairly freely only with the needle most of the way out, with flow reducing as the needle is pushed in, until almost no air passes with the needle al the way in. I wondered if there should be an air tight seal, but then possibly the needle would stick/jam ? I have never changed this part on a motorcycle before - had not considered that it would wear, except I was told that it could be a problem on these carbs. Now I really don't know, but don't want to pay Yamaha prices and don't have confidence that Yamaha are honest about their parts when I don't know for sure what the best specification is, nor whether I would get it if I ordered it ! Andy also checked the jet sizes for me - the Y-0 (DL model) is dia 3.10mm, the X-6 (TDK) is dia 3.08mm. That's not a big difference, but might have an impact on mileage/fuel consumption. We still need a lot more information, folks, and I suspect that it might be useful if people could check which model they have (ie by the engine/chassis number) as well as saying what they get to the gallon. Then I suppose I'd have to take on the task of collating the information and seeing if there's a link.

Hi Gearhead - I've got some new ones coming (hopefully tomorrow) and if they've got a thread fine http://i3.ebayimg.com/02/i/000/b1/85/fbdf_2.JPGbut from the picture I can't see one. The seller said they were for a V-max but I'm told they're the same. If the needles arthe same and I can't get the housing out then I'll just use the new needle. They will either fit or they won't - they weren't too expensive - they were off Ebay.

I suspect that I'm losing people's attention with the detail here, but for the record, while I've got my carbs apart I'm going to post the details of what I'm finding inside. Butterfly valve has 140 stamped on each disc. Needle is 5FX59 Needle jet is 438 Y-0 (90% sure it says 438 - don't know if that's the 'series' or not) [Y-0 jet diameter is 3.1mm, X-6 is 3.08mm] main bleed pipe is 9A main jet is 117.5 There is also a letter which could be H the jet block has 25 stamped on it pilot mixture jet is 37.5 pilot air jets are 80 and 170. I'll add more information as I keep pulling them apart (time to eat, now). I haven't taken the float needle valve seat out yet. On the microfiche it looks as if it should come out 'backwards' - ie through the carb body, but I can only see that it could be a push fit from the inside, with maybe an o-ring for interference. The manual doesn't say - can anyone say if is just a case of wiggling with a pair of pliers and pulling it out ?

Hmmm - why not go the whole hog and do an LPG conversion - same fuel for cooking and for driving and a chariot to keep it all in. I like my beer warm, but you could have a gas powered fridge too.

We call it an 'E' clip, although the shape is rounded more like in a Euro 'E'. If you're lucky your local auto store will sell them individually or in assorted boxes of 100 for a few dollars. I picked up a selection at Lidl or Aldi when I saw them there for about £2.99. Good luck.

Dunlop have the same size - 175/80 x16, but in some more interesting patterns. I saw they have the Elite 3 Bias and Elite 3 Radial in 160/80 x16 with a load index of 80. This is higher than anything else I've seen (77) in the standard size. Has anyone tried this size ? Was it a good fit and did it last significantly longer than what you had before ?

Looking through the Continental catalogue, http://www.conti-online.com/generator/www/de/en/continental/automobile/themes/tyretips/download/technical_databook_passenger_car_tyres_2008_en.pdf there is very little narrower than 185. On page 18 there is a 175/60 R16 available as a run-flat, but it is a winter tyre and might therefore get warm in the summer. Page 36-7 has operating limits, and the width is given as 184-194mm based on 5J-6J rim. If that's a measurement in inches then it sounds as if the tyre would have to distort considerably to fit. As an aside - probably of no use, the TEMPORARY use tyres on p64-5 have all sorts of interesting sizes, but they are designed for low speed use only. Maybe that's why the load indices are so high ! Page 65 has Vanco 175 tyres. The full specs are on p82 and show that it should fit a 4 1/2 J rim with a width of 179mm. Maybe I'll check the Dunlop catalogue next. (They do the taxi tyres.)

Here's a link to a taxi co tyre - it's 175 - maybe it will fit ?? http://www.taxi-mart.co.uk/shop/prodtype.asp?cookiecheck=yes&PT_ID=133

It will only kink if it is too long or there is movement, which there isn't. Don't try and over complicate a piece of pipe. A nice thick bit will look right and last for years, but anything that doesn't dissolve will do just fine for now. It certainly won't go brittle in the time that you wait for the postman.

When I looked at this a few years ago there were two avenues I wanted to follow,, but which unfortunately I had no chance to follow up. One was to try out a London taxi tyre. They fit a 16" rim and are not too wide. My understanding is that the bead is not the correct shape for a motorcycle rim, so while it may seal, in the event of a flat, it is more likely to come off the rim, just like a tube type tyre, which takes out a safety factor, but is not too great a risk imho. If memory serves the ridge for the bead is wider on bike rim than the car bead is wide. If it is the other way round, maybe you should consider fitting a tube. If you know it's okay and seals fine, great. In the UK it has always been legal to use a car tyre, or a rear tyre on the front, if you drive with a sidecar. The other possibility, which someone on a GSX1300 outfit shared with me a few years ago was that he was having m/c radial tyres remoulded with ford transit treads. I couldn't find anyone to do it though. He reported better wear and grip. Given that he was then using 150mph rated tyres at 80-90mph max he had no concerns about tyres shredding either. (There's the old chestnut - when you see shredded tyres on the motorway, what makes you think they were remoulds ?)

One thing to be aware of, depending on the market you're buying in: some specific trailer tyres are only rated for 50 mph. I've gone above this without any mishap with quite a heavy load (before I realised what the tyre rating was), but it is something to bear in mind if youhave a choice. Essentially 8" and 10" trailer wheels are freely and cheaply available (over here at least), whereas 12" are up-market and can use car tyres (and are more likely to be used braked) and are more expensive. You would expect the ride height to be higher with 12" wheels, but on more expensive suspension units you will probably be able to decide how to mount the suspension arm on the splines on the damper unit, so you can set the ride height to whatever you wish, so long as there is clearance. Smaller - cheaper, easy to source and probably fine to use if your tyres are up to spec. Larger - more expensive and likely to use tubeless rather than tube type tyres. [NB - regarding braked wheels - I tow with a sidecar, not solo.]

If I remember correctly (and am not confusing this with the cmputer on my XJ750) the little whizzbox does periodic checks, but also every time you engage a brake. If something is found to be wrong, the light flashes to let you know for a little while and then just glows steadily. When you accelerate hard, it may be that the vibration is enough to jiggle the brake light switch and trigger a signal. I don't know if you would get this effect if there is nothing 'wrong'. On mine I have an Odyssey battery and better front master cylinder and have not added extra wiring to fool the computer (which always thought my headlight was faulty anyway) so I get the warning red light, still or flashing anyway.

Why only use DOT 3 ? DOT4 (or even DOT5/5.1 if it says on the bottle that it will mix - ie not that funny Citroen silicon stuff) should be absolutely fine. Surely the higher numbers will give more protection against brake overheating and fade. The differences are not so great in practice, although I had thought DOT3 had pretty much disappeared. According to Wikipedia http://en.wikipedia.org/wiki/DOT_3 it's use is hanging on in the US though, for some reason.

That's the right screw. I'd be interested in knowing how you got on as I found it difficult to see much difference with the colortune on my VR. Admittedly I was working on a fairly sunny day, using a sheet to get shade when I needed it, but still it was showing a blue flame whatever I did - which would be fine if it did not use more petrol afterwards - I had to set it back to how it was before I began !

So Funrider you get 40 mpg US (about 45mpg UK) at 65mph and slip to 33-5mpg US (38-40mpg UK) at 80-90 mph. Some others are getting no more than 40mpg (UK) at 50-55mph and 30mpg (UK - 25mpg US) at speeds of 70-80mph. These bikes are in most cases sensitive to speed, but also to something else - the question is exactly what. It doesn't seem to be timing, so maybe it's carburation. Do you know exatly which model you have, or the engine number ?

I thought we were talking about a hole in the dash, top right of the removeable stero insert, but now I realise that people are talking about the hole in piece of plastic around the ignition switch. Mine too has a blanking plug, but looking at the manual for the standard XVZ12TK I can see that the schroeder valve for the air assistance on the front forks would have poked through here.

Now I don't want to seem obsessed by this, but ........ According to the microfiche I'm looking at for the XVZ12DL http://www.yamahaventureclub.co.uk/downloads/XVZ12DL.PDF on pages 15 & 16, the main air jet is 80, not 65 as stated in the manual - surely this would make the carbs run richer at low throttle openings. Additionally the pilot air jet is given as 170 in the fiche rather than 180 as stated in the manual. Hmmm - checking again, the L model microfiche has the same specs as the manual - maybe the manual supplemement for L, DL, KC2 and DKC2 rather unhelpfully left out the specifications/data for the last three of those. It doesn't help my confidence that the #65/#80 discrepancy can be explained by Yamaha mistaking the main air jet for the pilot air jets (and thereby leaving the real main air jets off the fiches altogether). I'm going to tear into it on Monday to be ready to do the float nedles when they arrive. I'll just have to see what I can get on the other parts and hope for the best, unless anyone has any inspiration, or a spare set of carbs that had been getting good mpg.

This is getting even worse. My mate's not answering the phone so he's probably having a liquid lunch atthe hostelry opposite his shop. In the meantime I thought I'd look up the yamaha part numbers om the microfiches for the XVZ12TDK, the XVZ12L and the XVZ12DL (courtesy www.yamahaventureclub.co.uk ) I get: model...........needle set........................... main nozzle (aka needle jet) XVZ12TDK.... 26H-1490J-00-00 .................26H-14941-06-00 XVZ12L ........26H-1490J-00-00 .................26H-14941-06-00 XVZ12DL ......26H-1490J-00-00 .................26H-14941-06-00 and the same for the DLKC2 model. I'll let someone else check the rest on the list. What gives, though. The original manual spec says that they had different settings, but the microfiches say they're all the same. Was there a recall and some carburettors reset (for the better or the worse ?) Was this applied to all markets? If anyone orders from Yamaha they'll get the same bits regardless of model. Was this because of continuous improvements or to meet emissions (ie possbly worse performance/economy) It does suggest to me that Yamaha messed about a bit with the jetting and it could be pot luck which specification people actually got. The question is, how do we work out which is the optimum ?

I always had an odd light, labelled in Japanese hanging around near there and assumedit was a warning if you went over 55mph or some such rubbish. I used it to put the switch for a wave band extender so I could tune to UK radio stations. A place to pump up the front forks would be handy though as my CLASS loses air. Or maybe it's the forks themselves... Either way, I wonder how easy it would be to reconnect (so I could get more than 22 psi).

I've just found the Alan's Performance site : it was Allen's Performance http://www.allensperformance.co.uk/ and I located the table below. Maybe they will be able to help after all - at least it has some 3 digit code numbers. Unless these are the codes they have not agreed to keep secret. I think TM and VM are their slide carb applications, not CV carb. The parts might be the same if we know the codes, though.. SeriesPart NumberSizeApplication110VM13/21-sizeE-6 to F-6VM16-353145VM15H1/17-sizeN-6 to O-6VM17-8101 / VM18-144 / VM20-151159VM34/05-sizeN-0 to R-0VM30-83 / VM32-193 / VM32-33 / VM34-168 / VM34-275 / VM36-4166VM34/17-sizeO-8 to R-8VM38-9175VM30/46-sizeO-8 to Q-2VM28-418182VM28/86-sizeO-2 to P-8VM26-8637 / VM26-8639224VM44/10-sizeAA-0 to CC-5VM40-4 / VM44-3239VM22/294-sizeN-2 to P-2VM20-179 / VM20-273249VM22/313-sizeN-8 to P-8VM24-473295VM13/151-sizeE-6 to F-0VM13-83325VM14/233-sizeE-4 to E-8VM14-8340332VM26/581-sizeN-4 to P-4VM24-489 / VM26-606389785-24001-sizeO-0 to R-8TM32-1 / TM34-2 / TM36-2 / TM38-85 / TM38-86426784-31002-sizeD-0 to E-2VM20-327454784-21005-sizeO-0 to q-8TM24-9512784-24008-sizeP-0 to Q-0TM28-1568784-13002-sizeP-0 to P-8 / Y-0 to Z-2RS / TM36-31 / TM40-6622784-232401-sizeN-4 to 0-6TM27-8006 / TM30-8006633784-13005-sizeQ-0 to T-0TM38-131 / TM38-157 / TMX38-1 / TMX38-5640784-24111-sizeP-2 to Q-2TM33-12680785-40004-sizeO-8 to P-8TMR/TDMR681784-31030-sizeD-0 to E-8VM16-438723784-430000-sizeY-4 to Y-8TM42-6 / TM45-2 /TM48-2

Aaaaagh I missed Alan's Performance yesterday (they close at 4:30pm) and they're closed today (Saturday) and won't open again until Tuesday because of the bank holiday...which will probably mess up my chances of doing it all this week. I rang the helpful guy at www.motocarb.co.uk again. He said that the codes in the manual are mikuni designations, but without the initial three digit series code are useless. essentially the series code give the external size, the figure in the manual the hole in the middle that supplies air/fuel. I asked if it would be possible to use the code from another model if we knew that series number (ie XV535 - one that I think kits are available for) but as the numbers are not stmped on the jet/needle there's no way to be sure. He also said again that neither these series codes nor the individual parts are listed in their catalogues due to an agreement with Yamaha not to supply them. I've got a friend who runs a Yamaha shop who I haven't visited for ages, so this may be the time to do it and just bite the bullet as to the price. Otherwise I won't know until mid week whether Alan's Performance can even supply the bits. Otherwise an email to Topham may be better than me struggling with my spoken German. It always seems easier for people to say 'no' when you email, though.. Model Venture XVZ12TK XVZ12TDK (has CLASS) Venture Royale XVZ12 L or DL Venture Royale XVZ12 KC2 or DKC2 frame no. JYA26H00*xxxxxx JYA31M00*DAxxxxxx (L) JYA41R00*EAxxxxxx (DL) JYA41V00*EAxxxxxx (KC2)JYA47R00*DAxxxxxx (DKC2) JYA47T00*DAxxxxxx Yam carb ID 26H 00 26H 00 41R00 main jet #117.5 #117.5 main air jet #65 #65 #55 jet needle needle jet 5GLZ37 X-6 5GLZ18-3 X-6 5FX59-1 Y-0 pilot air jet no.1 #80 no.2 #180 #80 #80 #180 pilot outlet 0.8 pilot jet #42.5 #42.5 #37.5 pilot outlet 0.8 bypass B.P.1 0.8 B.P.2 0.8 B.P.3 0.9 valve seat size 1.5 starter jet G.S.1 #45 G.S.2 #0.8 fuel level 14~0.5mm 16.5-17.5 mm 15.5-16.5 mm Mikuni ref ? BDS34 BDS34 BDS34 BDS34 carb diameter ? ?? ?? ?? mileage ?? Do people with this model get good mpg ? Do people with this model get good mpg ? I get low 30's mpg (UK) with this model solo, 30 mpg (25mpgUS). Do otherpeople with this model get good mpg ? Do people with this model get good mpg ? other comment I don't know how many of these were made. Manual lists only one pilot air jet. Changed float level. Were the changes to make the cruise control work ? The manual gives the code number, but no further information - I have presumed the L/DL info applies. I have no idea if we've been comparing like with like when talking about mileage/mpg figures. I also don't know how many later models there were -it took long enough to enter this lot (sorry about the big gap btw - I don't know why it is there nor how to remove it) I understand that at some point the carb body diameter may have been changed, but whether they are interchangeable (ie the same carb rubbers fit) I also can't say. If my jetting was altered to make cruise control, though (and all other cruise control riders get worse mpg than non-L/DL models) then it might be worth trying to switch carbs or do a re-jet - but surely someone else must have made this change in the past ??? What does everyone else think ? Meanwhile I think I need to ring my friend in the Yamaha shop - except he won't be able to order anything now until Tuesday doh: