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From: Al on 14 Aug 2006 15:52
I bought my first ever bike, a used 05 Suzuki Boulevard S50, a month ago.
When I first ride it after it has sat long enough to cool off it seems to
hesitate around and below 25% throttle (I'm not an expert, but that'd be my
guess.) After it warms up it seems to quit hesistating, but pops when
closing the throttle. It does run rich, and I'm assuming it's popping and
rich due to the fact that there are aftermarket pipes on the bike.

How long does it normally take for a bike to 'warm' up, if there is such a
thing. My first bike and I have nothing to compare to. How long do you let
yours warm up before you hop on it and take off?

Am I doing any damage to the engine? I'd prefer to wait until winter to
take it to the dealer and let them do whatever they need to correct the
richness and popping. Is this something I could easily do myself? I'm
semi-what machinically inclined. If not, what would you suspect they would
do to fix the problem?

Thanks,
Al


From: FB on 14 Aug 2006 19:44

Al wrote:
> I bought my first ever bike, a used 05 Suzuki Boulevard S50, a month ago.

I didn't know they still made the Intruder. I thought they had gone to
the ugly
fat fenders on all the models.

> When I first ride it after it has sat long enough to cool off it seems to
> hesitate around and below 25% throttle (I'm not an expert, but that'd be my
> guess.) After it warms up it seems to quit hesistating, but pops when
> closing the throttle.

> It does run rich, and I'm assuming it's popping and
> rich due to the fact that there are aftermarket pipes on the bike.

What, did somebody put ridiculously oversized main jets into the carbs,
thinking that was necessary with aftermarket pipes?

You're just guessing about rich versus lean. If you don't run wide open
throttle, huge main jets never come into play.

Big singles and V-twins do tend to pop and fart out the exhaust pipes,
especially when you roll off the throttle.

But the hesitation you describe is probably due to dirty carburetors,
especially the idle mixture circuits, which are critical to constant
vacuum carburetor operation during starting, warm up, and cruising at
small throttle openings.

Your machine has 2 carbs. Front: Mikuni BDS36 Rear: Mikuni BS36

The EPA has mandated that the idle mixture on motorcycles be
ridiculously lean to meet air pollution standards. This affects
starting, warm up, and throttle response.

If the idle mixture passages get the least bit dirty, the rider
encounters all the above problems.

My recommendation is, as always for my devoted readership, for you to
run down to
Wal*Mart or your favorite auto parts store and buy a can of Berryman's
B-12 Chemtool Choke and Carburetor Cleaner (aerosol or liquid form) and
measure out 3 ounces and pour it into a full tank of gasoline and go
for a putt.

As the B-12 cleans out your carburetors, the idle speed will increase,
so be aware of the location of the master idle knob.

If the B-12 cleaning doesn't work to your delight, you will probably
need to remove the carburetors and drill out the EPA anti-tamper plugs
concealing the idle mixture screws. Since I have described the process
a bazillion times, I won't type it out again.
>
> How long does it normally take for a bike to 'warm' up, if there is such a
> thing. My first bike and I have nothing to compare to. How long do you let
> yours warm up before you hop on it and take off?

30 seconds. By the time I get to the freeway, the engine is warmed up
enough to use more power.
>
> Am I doing any damage to the engine? I'd prefer to wait until winter to
> take it to the dealer and let them do whatever they need to correct the
> richness and popping.

It isn't rich, it's lean.

> Is this something I could easily do myself?

Yes.

> I'm semi-what machinically inclined. If not, what would you suspect they would
> do to fix the problem?

The $tealer$hip mechanic$ will tell you that your carburetor$ need to
be $ynchronized and that it will co$t you a$ much money a$ you have in
your wallet and maybe more...

From: Alan Huseby on 14 Aug 2006 21:30

"FB" <flying_booger(a)yahoo.com> wrote in message
news:1155599065.358539.25720(a)h48g2000cwc.googlegroups.com...
>
> Al wrote:
>> I bought my first ever bike, a used 05 Suzuki Boulevard S50, a month ago.
>
> I didn't know they still made the Intruder. I thought they had gone to
> the ugly
> fat fenders on all the models.
>
>> When I first ride it after it has sat long enough to cool off it seems
>> to
>> hesitate around and below 25% throttle (I'm not an expert, but that'd be
>> my
>> guess.) After it warms up it seems to quit hesistating, but pops when
>> closing the throttle.
>
>> It does run rich, and I'm assuming it's popping and
>> rich due to the fact that there are aftermarket pipes on the bike.
>
> What, did somebody put ridiculously oversized main jets into the carbs,
> thinking that was necessary with aftermarket pipes?
>
> You're just guessing about rich versus lean. If you don't run wide open
> throttle, huge main jets never come into play.

The exhaust was on the bike when I bought it. Have no idea if anyone has
touched the carbs, I haven't.

I assume then I'm backasswards with what rich and lean are. If the exhaust
has a strong gasoline type smell to it, is the engine lean, rich, or normal?

>
> Big singles and V-twins do tend to pop and fart out the exhaust pipes,
> especially when you roll off the throttle.
>
> But the hesitation you describe is probably due to dirty carburetors,
> especially the idle mixture circuits, which are critical to constant
> vacuum carburetor operation during starting, warm up, and cruising at
> small throttle openings.
>
> Your machine has 2 carbs. Front: Mikuni BDS36 Rear: Mikuni BS36
>
> The EPA has mandated that the idle mixture on motorcycles be
> ridiculously lean to meet air pollution standards. This affects
> starting, warm up, and throttle response.
>
> If the idle mixture passages get the least bit dirty, the rider
> encounters all the above problems.
>
> My recommendation is, as always for my devoted readership, for you to
> run down to
> Wal*Mart or your favorite auto parts store and buy a can of Berryman's
> B-12 Chemtool

I saw your B-12 recommendation earlier and picked some up over the weekend
and put some in the tank. Haven't had a chance to ride it too much since
adding it. Hope this takes care of it.

> If the B-12 cleaning doesn't work to your delight, you will probably
> need to remove the carburetors and drill out the EPA anti-tamper plugs
> concealing the idle mixture screws. Since I have described the process
> a bazillion times, I won't type it out again.

Will keep that in mind.

>>
>> How long does it normally take for a bike to 'warm' up, if there is such
>> a
>> thing. My first bike and I have nothing to compare to. How long do you
>> let
>> yours warm up before you hop on it and take off?
>
> 30 seconds. By the time I get to the freeway, the engine is warmed up
> enough to use more power.
>>
>> Am I doing any damage to the engine? I'd prefer to wait until winter to
>> take it to the dealer and let them do whatever they need to correct the
>> richness and popping.
>
> It isn't rich, it's lean.
>

Thanks for your time and response FB, appreciate it.


From: FB on 14 Aug 2006 22:17

Alan Huseby wrote:

> I assume then I'm backasswards with what rich and lean are. If the exhaust
> has a strong gasoline type smell to it, is the engine lean, rich, or normal?

Exhaust smell and spark plug insulator appearance can fool you.

The idle mixture can be so lean, the cylinder fires every other stroke
and the engine manages to kick unburned hydrocarbons out the exhaust
pipe and you smell gasoline and the spark plug insulator is a pale
grey, maybe even looking a little wet.

But, if the exhaust puffs out a lot of black soot, you can be pretty
sure that the mixture is too rich. The spark plug insulators will be
sooty black

Look at the underside of your carburetors, just forward of the float
bowls. If you see a slot-headed screw in a hole there, somebody has
already drilled out the EPA anti-tamper plugs.

If you only see the face of a round plug, your carburetors haven't been
violated in that way yet. You might want to mess with the idle mixture
yourself, as opening the idle screw half a turn does wonders for
starting and warm up and throttle response.

Shade tree mechanics who mess around with the idle mixture screws
usually turn them too far counterclockwise, expecting the idle RPM to
increase. But, when they turn the screws too far, the idle mixture gets
so rich the idle RPM actually slows down.

Then they turn the idle RPM up to compensate and this uncovers a
pattern of transition ports just downstream of the throttle
butterflies.

When they rev the engine up and close the throttle, the idle RPM hangs
up and the engine idles way too fast for up to a minute.

Then, mystified, the park the motorcycle in the garage for three months
while they watch football all weekend or take the wife shopping at the
mall.

The gasoline in the float bowls evaporates and they have all the
indications of a very lean mixture because the idle jets are plugged
up.

B-12 cleans the idle mixture circuits and the jets out.

Then there is the issue of jet sizing, assuming that somebody *might*
have messed with the main jets thinking that they had to install
monster jets to correct for the aftermarket exhaust system.

I have explained Mikuni and Keihin round jet sizing a bazillion times
in this NG.

The whole point is that the orifice size is based upon a #100 main jet
having a hole
that is exactly 1.000 millimeters in diameter. A # 30 idle jet would
have a hole that is
0.300 mm in diameter.

You can see by the area = pi times radius squared formula that a # 40
idle jet is a huge increase in area.

So, an engine that has # 30 idle jets might need to have the idle
mixture screws turned out 3.5 full turns from fully closed while an
engine that had # 45 idle jets might only require the idle mixture
screw to be open half a turn...

From: Al on 15 Aug 2006 18:47

"FB" <flying_booger(a)yahoo.com> wrote in message
news:1155608220.816828.105930(a)h48g2000cwc.googlegroups.com...
>
> Al wrote:
>
>> I assume then I'm backasswards with what rich and lean are. If the
>> exhaust
>> has a strong gasoline type smell to it, is the engine lean, rich, or
>> normal?
>
> Exhaust smell and spark plug insulator appearance can fool you.
>
> The idle mixture can be so lean, the cylinder fires every other stroke
> and the engine manages to kick unburned hydrocarbons out the exhaust
> pipe and you smell gasoline and the spark plug insulator is a pale
> grey, maybe even looking a little wet.
>
> But, if the exhaust puffs out a lot of black soot, you can be pretty
> sure that the mixture is too rich. The spark plug insulators will be
> sooty black
>

That makes sense.

> Look at the underside of your carburetors, just forward of the float
> bowls. If you see a slot-headed screw in a hole there, somebody has
> already drilled out the EPA anti-tamper plugs.
>
> If you only see the face of a round plug, your carburetors haven't been
> violated in that way yet. You might want to mess with the idle mixture
> yourself, as opening the idle screw half a turn does wonders for
> starting and warm up and throttle response.
>
Nope still in place, well were. I took the plugs out, gave the front
cylinder 1/2 turn out and rear 3/4 turn out and no more hesitation. I'll
keep an eye on the plugs. Does do wonders. The poping sound happens a bit
less frequent now too. Thanks again for pointing me in the right direction.
You are my new hero. :)

Thanks Again,
Al


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