Try this, Put a lubrication based fuel additive in, this will tone down the sick azz gas blend no matter what it will be better.
I'm using Lucas fuel treatment but anything like marvel mystery oil, will work, I just used lucas because it does not clean too much. You want something that says Upper cylinder lubricant. Lucas fuel additive. You only need a shot for it to work. I went pukeless all day today. I may be onto something and it may just be the sorry gas we are getting and........ me being the king of SVS due to the intake leak, I have abused using seafoam. (Also use it as a anti-freeze in the winter. But I made the switch to Lucas this week.

All I know is that my bike will do this too,but only on a hot day of like 90-95 degrees and in traffic,because the bike is'nt getting cooled down from the wind like it would on the highway!!! But on a hot ass day and riding on the highway and parking the bike for a little bit and going to start it again it won't do it... Thats just my expeirence with this.....

I think we are driving the MODS crazy! Especially DOC.
Great mine only does it when stopped. So I am glad of that.

Good call! I have been considering putting some Marvel MO in the gas. Mine puked today pretty good, it was 90 here and I ran it 60 to 80 in the wind for about an hour, turned off the pet cock and it still puked when I went to start it again. I used sea foam over the winter and am wondering if it shrunk the seals in the carb.
Please keep us updated!

chico wrote:
All I know is that my bike will do this too,but only on a hot day of like 90-95 degrees and in traffic,because the bike is'nt getting cooled down from the wind like it would on the highway!!! But on a hot ass day and riding on the highway and parking the bike for a little bit and going to start it again it won't do it... Thats just my expeirence with this.....

There are a ton of factors to consider of course. Some of them will seem minor but can be the tipping point for some.

For instance, the stock pump with cover and the stock air cleaner both restrict the amount of airflow between the jugs. Riding in slower traffic does two things; less airflow and the lower rpms means the fuel is gathering more heat from moving through the line slower between the jugs. Riding at higher elevations can be significantly different due to the thinner air and therefore, again, less airflow.

All or some combination along with ambiant air temperature can be related. Any way you look at it, for those that are dealing with this, it is temp related to the fuel line, float bowl needle valve/valve seat and float bowl.

Ratl.

MS1700 wrote:
Try this, Put a lubrication based fuel additive in, this will tone down the sick azz gas blend no matter what it will be better.

Hmmmmmmmmm Now that you mention it, I ran a capful of MMO in just about every tank last year. No puking. This year so far have not ran any MMO and 3 separate episodes of puking! May be a coincidence but do you think that just a capful of an additive can change the complexity of 4 gallons of gas enough to keep it from expanding or boiling?

Here I go again:

I want to thank you all for taking an interest in my dilemma. Got a kick out of Mry75. I think he is dating himself. I am almost 66 and can remember vapor lock. However, I have had my Road Star at two dealers, spent several hundred dollars. Last time even the dealer was able to duplicate my complaint in the shop. In all cases, I insisted that Yamaha rep be contacted for advice. Good service rep and I am confident they did. Floats have had several adjustments, needle/seat cleaning and adjustments have been made. There is not a dirt or debris issue. Float adjustments have helped (it is not as bad now), but has not eliminated the problem.

The one thing we all agree on it that it is heat related. Chico makes a good point in that high altitude makes matters worse. This may be why I did not notice the problem in CA, but it came to life here in CO. However, the after market changes without a guarantee of success can get expensive. There is a limit as to how much money I can throw at the problem.

For MS1700, I will try Lucas or Marvel MO. Not too wild about a Mechanic in a Can, but if it works the price is right.

I still think the best solution and cheapest in the long run is to file a complaint with the NHTSA (http://www.nhtsa.dot.gov). There are Yamaha engineers that can figure out how to fix the problem. As I said this is a fire hazard. A spark or a careless smoker at the wrong time could spell disaster. Please do not tell the EPA or they will have a bill in Congress to outlaw our rides. The last time I checked, raw fuel into the atmosphere was not legal.

I did find it odd that this is a problem for many and from all over the country. Not one reply indicated that a written complaint was worthwhile or not or even a good idea. If you are having this problem, consider filing a complaint. Nothing will happen with my single complaint, but if others file then ???????.

Guess I will have to get off my soapbox. Again thanks to all and next time hope to be able to contribute something a little more positive to the Clinic.

Ok Pukers! I new solution, forget the Lube based gas additive, That didn't work. No so sure the seafoam makes it puke either. But, my latest experiment seems to be working now 3 days no puke in a puke friendly environment (Above 50 degrees)
1st How serious I am.
Yami dealer working very close with me and supply the parts and labor if needed, I choose to DIM (Do It Myself) as I clean and do other thing along the way. Anyhow, We determine it is heat related, We suspect because i had Benn Herr manifold installed and retain factory fuel pump and location and factory block all circulation air cleaner.
Dealer wants to solve with them intact and go by strict fix one thing at a time so we know what did it.
Last week I decide to eliminate the heat from the fuel line possibility, So I removed the old line, and installed a new and insulated the dog doo out of it going in between the jugs.

This is Ben Herr manifold, It brings carb slightly closer to jugs and heat transfers easier from metal to metal. Have this and a stock air cleaner and your asking for trouble, But what jerk would do that? Me.

Ok so here is a stock fuel line, it's metal and comes close to Jugs at one point it touched. Above it is new rubber line about to be installed, Rubber retains less heat?

So I covered the line with the same protective spring found around the fuel pump, Then you see two types of heat insulating tape here, (I used 3) 1st I cover with spring, then with the Heat insulating tape with foil and sticky foam, then I cover with plain Foil Duct tape to smooth it out and seal and then with the Hot Rod 1700 degree heat insulating Cover shown (By DEI) I though man this is the cure!

Look at the insulation!

Well after all that work, 1st ride I got a puke on 1st start up.
So back to dealer, we eliminated that for sure and still Puke.
So we come up with idea to put a rubber boot in between the intake and the carb so no metal to metal contact. Dealer takes about 10 minutes and hands over a bag of parts to allow for the extra room and distance to get air cleaner maybe an inch further out. I go home and dig in, Guess what? No room, carb will hit Gas tank so this can't be done.
So, I say ok, I have some leftover sticky insulating tape and although we tired this before we have not tried a direct application. (Before we just made a fit over shield) So I stuck it on, what's to lose?


So I rode around all weekend Schatzie was looking for a car for her freshly licensed teen and we went creeping through car lots, heating up the R like I would be sure it would puke, but no! I even tried a few drive it like I stole it runs and stopped and started again, but No puke! Then the next day it was even hotter, and still no puke and it seems to run different. Like it's ingesting cooler gas now instead of boiling gas. Seems to run fatter with a spit of smoke out the carb 3 times on startup after a stall.
I really think I am onto something, I really thing the tape on the forward side of the carb next to the jug is really what did it. (I put two layers there.
Ok, experts chime in!

Sounds like your becoming the expert authority on puking!
It definately looks like you have narrowed it down to a heat problem, just a matter of geting the sticky shiney stuff in the right places. It's a lot of leg work, but I think eventually a lot of guy's on this site are gonna thank you for it.

Damn I can't Reply to this thread.

So if I understand you correctly the Ben Hur manifold has a short intake and the carb is touching (or close to) the jugs? That would explain why the fuel is boiling.

In comparison ... my Nemesis manifold has an intake about 7/8" longer than stock ... the carb is hanging way out there. This may explain why I have never experienced this phenomenon and you do. Our differing setups would not, of course, explain why some stock setup puke and others don't.

Doc