Cruzers for the ACE 750

[prman]

Just ordered Vance and Hines Cruzers for my Ace 750. Can't wait till they get here next week. Once they are on, I'll post some pics. I've checked the search button and it looks like I won't need to rejet since I'm not doing any other mods to the carb.

[prman]

The V&H Cruzers are great. Nice sound. They went on easy. Today I drilled the covers over the mixture screws and adjusted them. That took care of any popping on deceleration. This was a great mod. I would like to get a K&N filter. Then its on to the next mod.

[bsa_bob]

Did you get your pipes yet.. want to see them . bsa_bob

[Lynne]

Today I drilled the covers over the mixture screws and adjusted them. That took care of any popping on deceleration.

I have these pipes and get popping sometimes when I decelerate. Sounds like a backfire. Can you explain or point me to a link describing what you did here?

[prman]

Lynne, I haven't taken any pictures for a long time. One of the other brothers on this forum posted the 1..2..3.. step process to do that adjustment. I will look to see if I still have that link. It is pretty simple just takes a little guts to actually drill the cover over the adjustment screws. I don't have any popping at all any more.

[Dcfam]

Here's how to change your fuel mixture. Description with pics for the ACE:
http://whytlash.powweb.com/
Once your at the site click on : Modifications then click on Exhaust, then the first one which is Stock exhaust Mod.
Now scroll down to the end and it tells you in detail how to change your mixture.
I would give you the direct link, but for some reason it won't work unless you give the home page.

Good luck. It's really not too tough though. Just go slow

[Lynne]

thanks dcfam.

I was doing a bit of research and came across this:

Burn Baby Burn

The last thing I want to address today is the subject of deceleration backfire, or "popping". This topic generates a lot of concern from inexperienced riders, or even from experienced guys who just hate the noise, so lets take a look at what causes it. But first things first, lets define the issue:

Deceleration Backfire is caused by fuel burning in the exhaust manifold or header.

No ifs ands or buts, that's what causes it. But the bigger question is how does gas get there in the first place, and that's a bit more complicated. Generally, there are a variety of ways it gets there, and a variety of things that can make the backfiring worse. But there's a kicker, and something you should understand before we go any farther:

A motor in perfect tune will exhibit deceleration backfiring.

Therefore, just because your motor is banging it up, doesn't mean there's anything wrong. And consequently:

Getting rid of the noise means de-tuning your motor.

Yup. If you've jut got to eliminate that popping, you'll have to accept the fact that your motor is going to be forced to run rich to do it, and that isn't necessarily a good thing. So lets talk about what causes the problem.

Ok, so you're riding along at some given rpm, and suddenly you decide to decelerate, and you reduce the amount of throttle. This causes an "overrun" - that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.

First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results in a lower pressure in the combustion chamber. Remember I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower. This results in two things happening.

1. The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to "quench" the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust.
2. The engine designers, in order to promote smoother idling and better combustion, retard the spark when the throttle is shut, and this results in the mix being lit later.

So, now we end up with unburnt fuel in the exhaust, and burning fuel being ejected into the exhaust, and bang! Backfire. In addition, Hondahas added a device called a "programmed air injection valve" (Pair Valve) that actually injects some fresh air into the exhaust to help this process along - since fully burning the fuel results in cleaner exhaust. So the backfiring is not only a normal part of the engines operation, it's also intentionally amplified by Honda! Of course, normally, that massive bazooka pipe Honda hangs on your bike hides most of the noise, but it's there, even when you can't hear it.

So the bottom line, is: That backfiring is perfectly normal and expected. If you've just got get rid of it, that's up to you. You're entitled to set your motor up the way you want, and your goals are your goals. But don't refer to it as "fixing" the popping. Rather, the correct way to think of it is "de-tuning a bit to get rid of the popping".

There are a few ways you can do this.

First, use the stock pipe. It will hide the sound, by absorbing it into mass, and masking it with the larger baffle space. Second, you can add more fuel during deceleration. This has the effect of raising the chamber pressure slightly, which burns a little more before the exhaust valve opens. Lastly, you can remove the Pair valve, which reduces the amount of available oxygen in the pipe to burn the unburnt fuel.
http://www.vtxoa.com/forums/viewtopic.php?t=28918
from http://hondashadowacetourer.yuku.com/topic/9559 (but copied from another url, now dead, and apparently cut off)

Does this make sense?

[Dcfam]

Yeah that's correct, your bike will probably backfire a little, but the degree of backfire is the key. Running your bike too lean (less fuel/more air) will burn up your valves, where running your bike too rich (more fuel/less air) will only foul up your plugs. If you run your bike too rich it will be a little sluggish but you won't ruin anything. So my suggestion is error a little richer than leaner and you'll save money in the long run. Just my 2 cents.

[Lynne]

okay I finally looked at the instructions and it looks pretty easy. Thanks again, Dcfam. I'm wondering if this is my problem, though, because it wasn't a problem until my last tank of gas (maybe). I'm going to get some Sea Foam for the next fill up and see if it makes a difference. I've been using Stabil but I'm reading that's not so great for gas with ethanol. This bike was also stored for 5 years so I'm wondering if the carbs could be fouled or if there is rust in the tank. Seems like it would have been evident 150 miles ago, though, right? I had Honda do the 600 mile service and there were no problems according to them.

The plugs on the air mix screws are still in tact so they have never been adjusted from the factory setting... Perhaps this was a problem before and I just never noticed in my n00bness. Did you hook up a tachometer to make these adjustments while it was running or just go by number of turns?

By the way, I'm an enginerd (electrical) so yes I over think EVERYTHING.

[Dcfam]

No you don't need a tach or anything. Factory is 2 1/2 turns out. I went 3 1/2 or 4. Just go 4 and take it for a ride. It won't cure all, but i should pop less. Sometimes you don't notice your bikes running lean until the air gets a little cooler. I'm not sure where your from, but as the humidity changes you'll notice it running differently too. i'm not familiar with sea foam, but you shouldn't put stabil in unless your planning on letting the tank of gas sit for more than 3 months.

[Lynne]

you know, before we bit the dust yesterday, the bike was running beautifully. It was warmer than it has been, low humidity. Very little (almost no) popping. So I'm thinking you are spot on about the weather being a factor in the changing performance. I still plan to adjust the mix, though. Was going to do it last night...