There should be no problem passing even with the stock jets so probably got a float problem or may need the pilot jets cleaned up (if it doesn't idle well). Make sure to set the sync too.
Sean
Sean
Would you do it???
- Thread starter usmc-vmax
- Start date
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Buy an A/F guage and weld an O2 bung into the pipes. You can then monitor the readings like they will be looking at and see what it's doing. Probably spend not much over $100 to do this. Did they give you a chart from the previous test?
Sean
Sean
No that just the levels were off. It was only the portable test, which they stick a metal wand into each muffler and take the reading. The real test they attach a hose to each muffler and then they both go into a machine for the reading, so it is possible that they would balance out that way but I am just trying to ensure that it passes because like I said before it does cost about a $1000.00 bucks depending on the yen conversion rate. Thanks for all your help, I think I am going to re jet the carbs and then just go for it and see what happens.
OK went and talked to my mechanic again today(I Can't do it myself) and told him that I wanted the carbs re jetted to a smaller jet. When I say that he tells me that he had to do that for another star bike, not a vmax though. He suggests we go all the way down to 80mm to ensure that it passes and then put the stock ones back in or what ever size I want after the check. Remember all of this is translated through his Jenglish cause I don't speak Japanese. It's only gonna cost about 75 bucks total for him to re jet it. What do you guys think?
Not sure what 80mm is but I would go smaller for sure. Not sure if the sniffer will pickup on the extremely lean condition. What is the conditions of the test? Do they put it on rollers and run the rpm's up? Or do it at idle??
Sean
Sean
$75 aint bad at all if you can't do it yourself. for someone who knows carbs but not necessarily a vmax its probably an hour or so of work. Especially if they don't know you can change mains by just flipping the carb rack upside down.
yea an 80mm jet would be quite big! maybe double check what he meant there.
yea an 80mm jet would be quite big! maybe double check what he meant there.
I thought the stock was 152.5 mm? So wouldn't the 80 be smaller? They do both types of test, an idle to start and then they get the rpm's up. I used this same guy(owner/operator) on my last VMAX when I was here 8 years ago. They also hold the bike overnight and do another test after it sits in a controlled environment. Thanks for all the help again. I Love the bike and I know that I need to learn to do the work my damn self, but right now I don't have the time to experiment and possibly screw it up.
Yea your right its not mm, it is the number of the jets. So it is mikuni 152.5 and going down to mikuni 80's. Is there a risk with the 80's??? The bike will only be ran for about 30 minutes or so for the test. He did do it to another Yamaha bike to get it to pass but it wasn't a VMAX. Now Im worried.
naughtyG
Well-Known Member
I honestly do no believe that a Max can run at all with 80 jets. The smallest I've heard of anyone going is 147.5, or maybe 145. You simply won't get enough petrol for the thing to be able to breathe..
147.5 main jets, and the A/F screws out by 1.5 to 2 turns (baseline adjustment is around 2.5 turns out) should most definitely be way lean enough to pass just about any emissions test, IMHO.
147.5 main jets, and the A/F screws out by 1.5 to 2 turns (baseline adjustment is around 2.5 turns out) should most definitely be way lean enough to pass just about any emissions test, IMHO.
naughtyG
Well-Known Member
How is your test done? Only on idle, or so they rev it too?
Mains are only for wide open throttle, A/F screw controls idle
Mains are only for wide open throttle, A/F screw controls idle
Well guys I made a decision....NOT to do the emissions test. I figure by the time I go through all this hassle, I will have about 2 years left here. I don'twant to take a chance of running it to lean and damaging my bike, plus it rains alot here so I wouldn't get a lot of riding in anyway. So with all that said, plus it's a grand to do the test and it's not gauranteed that it would pass anyway, I will just wait till I'm back in sunny AZ. Thanks for all your help and advise!!!!
