boggy low end?

The Penguin

The Penguin

triple secret probation
Location
down by the river
61X top and bottom (no porting)
lightened flywheel
CDI with rev limiter disabled
riva pipe
can't rememeber jet sizes right now
95 gm spring
probably 1.5 n/s

I seem to have a bogging problem off idle.

when I'm idling or just off-idle riding around and go to grab a handful of throttle - I'm getting a bog.

If I'm riding around about mid-speed and punch it - there seems to be no issue.

My low speed adjuster is out about 1 to 1.25 turns out. should I turn in the low speed screw a bit more - or try going to a smaller jet size?
 
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Mike W

Mike W

Infidel
Location
North Florida
The Penguin said:
61X top and bottom (no porting)
lightened flywheel
CDI with rev limiter disabled
riva pipe
can't rememeber jet sizes right now
95 gm spring
probably 1.5 n/s

I seem to have a bogging problem off idle.

when I'm idling or just off-idle riding around and go to grab a handful of throttle - I'm getting a bog.

If I'm riding around about mid-speed and punch it - there seems to be no issue.

My low speed adjuster is out about 1 to 1.25 turns out. should I turn in the low speed screw a bit more - or try going to a smaller jet size?
Click to expand...

Once your idle speed is adjusted there is never a need to adjust them. Your problem sounds like you are rich. Like ski4 said, turn your H/S screw in a bit and see what happens. Or you may need to adjust(raise) your popoff.
 
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ski4

ski4

gonzo
Location
cleveland
i always thought bogging was a rich condition and hesitation lean,

of course in the real world i can never tell the difference when tuning my boat.
i just turn screws till things feel better


i always thought though, in the dog days of summer and when water temps rise boats tended to run rich
 
The Penguin

The Penguin

triple secret probation
Location
down by the river
more info:

140 high
low - unknown, can't remove it (carb came from a stock 650, so most likely that's what the low jet is)
dull silver spring
1.5 n/s

my plugs are quite black which is why I thought too much fuel

I put new adjuster screws in today, so I'm going to play with those a bit to see if it helps.
 
WFO Speedracer

WFO Speedracer

A lifetime ban is like a lifetime warranty !
Location
Alabama
Fiddling with the high speed adjuster will do nothing for a low speed bog,the main jets only come into play at 1/2 to w/o throttle positions.Turn the low speed adjuster out a turn more and see if that helps,if you have a low speed jet in there that was running on a 650 then it is way too small for your current setup.
 
Melmack

Melmack

(Timothy)
Location
New Braunfels, TX
On the contrary if you gun it from idle, you are now at full throttle. Water speed has little to do with whats going on in the carb. The high speed screw could help unless pop-off is out of wack. If the idle is just right, and works ok from cruise to full, then try leaning out the top or the bottom just a hair(make notes of where you started and ALWAYS GO BACK). The Idle setup is key here. Make shure you set the idle just right. First lean it out till it revs up too high on it's own. Then, richen a quarter for throttle response. Then adjust the top using a high speed test (10 sec minimum). If the plugs are light brown, your good. My SX idle was a little to rich recently and it would do the same thing. I leaned the bottom out a bit and whalla.
 
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Mouthfulloflake

Mouthfulloflake

ISJWTA member #2
Location
NW Arkansas
YES.

its taken me this far this season to realize this.

Top end jetting has EVERYTHING to do with pretty much all throttle position above "barely on it"

do as instructed.. set the lo speed screw, then adjust butterfly stop screw for desired idle speed, THEN lean the Hi screw until it screams.

then fatten it back up 1/8 or so.
 
WAB

WAB

salty nuts
Location
coastal GA
The Penguin said:
..... I've just dealt with it.
Click to expand...
I 'just delt with it' also all year....thought that was a good as it would get.
Dropped a pilot jet size (125 to 120) and tuned adjustors in better. Getting the jetting just right is like getting an extra 20hp, with or without a head or a drier waterbox. :burnout:
Keep messing with it.
 
The Penguin

The Penguin

triple secret probation
Location
down by the river
when I say soon - I mean within the next few days.

I would have the b-pipe in my hands today if it weren't for UPS delaying all ground shipments through Louisiana due to Gustav. I was intending to install the pipe and head this weekend.

assholes.
 
WAB

WAB

salty nuts
Location
coastal GA
Get a better carb, not an old one from a 650 with a stuck pilot jet you can't change. :slap: At least grab one of those $70 single 46's
It had to be said :popworm: :fing02:
 
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