Gio

Hey guys, I agree (with Al) in that (as an experienced vapor-locker!) the problem has never occured whilst in motion, only after stopping for a while and trying to re-start. Also, if experiencing mild pre-vapour-lock (spitting and coughing) one can sometimes ride through it - once the air-cooling/and or fuel-cooling gets going things seem to be fine (this happened to me a couple of times this summer whilst riding in ~30c temperatures) The other point I note (callison) is that you were able to re-start after only 20 seconds. I have had to wait for up to an hour (eg the last two experiments I did - both vapour locked at 48 mins) before the bike would re-start. So that would make you todays lucky winner! Stay tuned - I have results from the heat-shield experiment #3 coming up. Gio

Thanks Al - the fewer variables the better in this case. Hoses are now replaced and heat-shielded, as is both fuel pump and filter. Just waiting for two 3/4'' FI hose clamps (the stock ones are crap / worn out) and I will be ready to see if this has any beneficial effect... Gio

Captain, Don't worry about running 0.15 / 0.20 mm clearances. I currently run the Euro spec of 0.10 / 0.15 mm (0.04 / 0.06 thou) but am thinking of trying 0.15 / 0.20 next time....(if I ever get out of vapourlockville that is) John T, I tried to measure the hot clearances for you, but couldn't see through the hot oil mist with the engine running... (good question though) Gio

As promised - here are some preliminary results of the vapour-lock expts. I used an infra-red thermometer to measure various places (cylinders, supply and return fuel-lines,fuel pump etc) using the two different maps following a test run of ~ 40km, calling this t=0 mins : M706.002 map (what I was running prior to airboxtomy) Ambient temp = 40F Cylinder temp at end of run = 235 - 237F Supply fuel line (LHS) = 130F Fuel pump = 173F Return fuel line (RHS) = 88F V11TomH map (much richer map - feels good) Ambient temp = 48F Cylinder temp at end of run = 213 - 216F Supply fuel line (LHS) = 116F Fuel pump = 157F Return fuel line (RHS) = 87F So my initial conclusion is that the richer map reduces peak cylinder temperature (by approx 21 + 8 ambient = 29F) as expected. However, despite this, after 15 mins, the temperature of both the supply fuel line (118 and 123F respectively) and fuel pump (134 and 130F respectively) were similar. I have data points every 5 mins and have plotted the cooling curves for each location (I guess I could post the graphs - not quite sure how to do this..) So the main conclusion from this experiment was that although a richer map reduced engine temperature as expected, the main fuel line and pump were heated to similar extents. Vapour-lock was present in both cases ( engine would not start at t=48 mins after end of each test run. So my next experiment will be to heat-shield the main fuel-line and fuel pump. Gio

I used to run 33/36 (BT010) but now prefer 38 on the rear. Just about to fit my second front and third rear (getting ~16k per front and ~12k per rear) Gio

I found the following map at www.guzzitech.com (thanks to both Tom H and the Guzzitech site for making this available) : V11-TomH.map (K&N filter, top of airbox removed, Mistral ovals, stock x-over) This closely matches my congfiguration (K&N, drilled airbox with snorkels removed, Mistral round, stock x-over) and in comparing with the map I'm running (706.002) note significant richening (particularly at low and mid throttle) which should result in a cooler running engine. Before re-locating the fuel pump with the new hose (which has now arrived), and unless anyone has a more appropriate suggestion map-wise, I plan to load this map and see if it has any beneficial effect on the "vapour lock" syndrome...? Later, Gio

I agree - shifts are much smoother since switching to Red Line MT-90 (75w90, no moly) and also keeping the shifter linkage lubed. Gio ('00 V11S)

Nothing wrong with a few "go faster" flames as part of the paint job anyhow... Gio

Looks like a nice bracket but I think that this would only help cool the pump once it becomes hot - in this case a better strategy might be to prevent it becoming hot in the first place (ie reflective heat shielding)...? All of which assumes the source of the heat is from the engine Having said that, if the pump was mounted out front as on some models, this would certainly look better than stock. Gio

Shoei RF800 with stick-on dog ears. Love it. Gio

Hi Janusz, I fully agree with your logic - and would welcome the opportunity to try (or at least compare) your map with the one I'm running to see if I get the same benefit as you seem to have done. This would be most usefull prior to any further changes on my part I think (Forum folks - is there a place that we can post PC maps on the site for this?). I would also agree that a fan should be the last resort. But, my reasons for wanting to go ahead with the fuel supply mods also include the following : 1) There seems to be a wide range of susceptibility to the problem (ie owners have experienced vapour-lock to different extents, or even not at all) 2) Based on the crap that came out last time I changed the filter, new lines would not be a bad idea as these could well be the source of the particulates 3) Even if the location of the fuel-pump proves not to be the main problem, I figure it would rather spend the rest of its days in a cooler climate than stock. Thanks again for the feedback, Gio

Thanks - I'll order some today. Gio

Al, I did a search on Aeroquip and came up with this link : http://www.bakerprecision.com/earls22.htm 1) Does the FBV0800 (0.5'' id / 0.75" od) look like what you were referring to as AN-8 in your previous post? 2) I assume you used this just on the 7/16" primary (tank to pump) line? Gio

As posted earlier under the hole in air-box thread, I have recently twice experienced increased vapour-lock symptoms under much cooler (~15c) conditions than previously (~25c+) after removal of air-box snorkel arms and drilling the lid. I'm running a K&N filter and PC with 706.002 map (mistral/stock x-over). On both recent occaisions, I took the bike for a short ride, stopped for approx 20 mins and then re-started without incident. Upon stopping for a second time the bike went into classic cough/splutter/back-fire and die mode. I tried allowing to cool (approx 20 to 30 mins) but in the end pushed to nearest gas station and sprayed cold water over the primary fuel line and pump followed by compressed air for an evapourative cooling effect. Started no problem after this treatment on both occaisions. Unless I've missed a revelation over the last few months, my understanding is that the best guess on the cause remains heat-soak into primary fuel-line and or fuel pump. The above observations support this. My plan of attack is to 1) re-locate the fuel pump (still searching for a source of 7/16 hose) 2) insulate with Thermo-shield/sleeve (ready to go) and 3) if necessary add a cooling fan. Any updates or suggestions are most welcome as not riding is not an option for me. Gio

Hi Janusz, I agree that the partial "airboxtomy" (excellent term btw) must have leaned out the mixture further and thus the engine would be running hotter as a result (with hind-sight it would have been interresting to measure), but I detect no symptoms of an overly lean condition. I have been away from the forum for the last few months, but would be very interested to learn what changes you made to the PC map which cured the problem. Gio

By way of an update on the air-box mods, the new plugs are turning a nice chocolate/tan colour indicating that all is ok with the mixture.... BUT - I have experienced the dreaded "vapour-lock" twice in the last few days under considerably cooler conditions (~15c) than previously - I'll pick this up under the vapour-lock thread (listed under FAQ) but my first thought was that without the airbox snorkel arms, hot air from the engine can now fill the air-box quite easily (which is where the temp sensor is located..) (Having said that, a liberal dose of cold water over the fuel lines/pump followed by a blast of compressed air from the nearest gas station got me going again ie classic heat-related symptoms) Gio

I recently cut the snorkel arms off my air-box and also drilled the stock lid with 27 x 1/4" holes. I run a PC and K&N filter. There is a definite improvement in response and the associated sound is quite acceptable (enjoyable). I installed new plugs and will monitor fuel consumption to see if this improves. Gio

If, as you suspect, the leak is from the piston seal, then you just need to replace this seal. It would be a good idea to remove the piston, clean the whole caliper assembly (mild soap and water works well) and allow to dry thoroughly before doing this. Be carefull not to scratch the piston or caliper bore however. Gio

I show part # 30-30106000 for the Weber fuel filter on my Y2K V11S Gio

That insulating sleeve looks interesting. Is it reasonably priced (I see form the link that it is offered in either 3 or 12' lengths so I guees you would need more than 3')? How about flexibility? Gio

I recall from one of my early "in-warranty" service visits that the splines in my Y2K V11S bevel box were found to be dry (this was one candidate for the rear-end howl)...so I would check yours if you haven't done already. Rear tire changes are a good opportunity to keep an eye on this subsequently as the wheel is out anyway. Gio

I believe this to be approximately 7/16" (am still looking for a source myself - nearest I have found so far is 3/8") Gio

I couldn't agree more. Whilst it can be tough to work through some of the issues (I have had my share on my Y2K V11S) support from my dealer was excellent. Also, having sorted the majority of the issues, the bike now seems much happier out of warranty (....how do they know?) I'm still a believer. This is a great bike. As far as the synthetic tranny fluid goes - this made a huge difference to shift quality - but I did hear (from my dealer actually) that there were some reports of leakage problems if moly was added (?) Gio

Come to think of it I haven't seen Tiddles in a while...? Gio

I took the opportunity to raise the forks by 3mm after installing a Magni on my Y2K V11S (stock was flush to the top of the tube) but also increased length of pre-load spacer by 11mm in order to decrease sag. Gio