was 130 DR loss of power - now CP21 jetting
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Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Tue Jan 08, 2019 1:08 pm quote
out of curiosity, Jack and all - how many of you move your main jet for winter and how much do you move it by? I have never done so before but it does make sense.
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Mon Jan 21, 2019 8:19 am quote
main jet 116->120
temps now 344 WOT

pretty good, could probably get another increase yet, was not stumbling or running noticeably rich anywhere.

122 should get me to the "normal" temp range for this bike.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1209
Location: London UK
Mon Jan 21, 2019 9:00 pm quote
344F at the plug is a good temperature if at WOT for 10miles straight. I would be more comfortable if this was 320F but the spark plug colour will confirm either way. There is usually more power running cooler anyway.

The Summer/Winter difference is usually just a trim of the airscrew and one main jet size. If a carb is set up correctly it hardly notices.
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Mon Jan 21, 2019 9:04 pm quote
On the way home I got some of the power increasing as you back out wot to 3/4 so I think it will stay at 120. Itís a compromise for cold mornings vs. warmer days. Will have a look at the plug to be sure.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1209
Location: London UK
Mon Jan 21, 2019 9:09 pm quote
3/4 going better than WOT is usually a sure sign the main jet is too small.
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Tue Jan 22, 2019 6:31 am quote
Maybe itís worth one more upjet then. Can do.
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Sat Jan 26, 2019 5:58 pm quote
Looks like it wasn't the weather after all. Had a group ride today, and it's not cold. It's a hike to get out there. There's a wide open stretch on the way where temps just kept going up (355) and then a stop light. At the light, the idle wouldn't come down or respond to a throttle blip, but eventually chilled out. That got me thinking on fuel flow - bowl going empty?

The ride was a bit Jeckyll and Hyde, with a bunch of city riding followed by wide open riding. In the city, nary a trace of leanness or misbehavior. On the wide opens, any time spent at 50MPH+ would keep getting hot.

Got home, decided to do the fuel flow test. 2 minutes, 25 seconds to flow a pint with the fuel line and quick disconnect in. Next, cap open, same result. Next, remove quick disconnect = 45s. Bingo.

I've ordered a new one, they're quite handy. This one is not a straight through but stops the flow if you disconnect it. It's a nice feature and worked fine for 4-5 years, so I will get another. It should be fine as it was in when I jetted the bike. I ordered some fuel line to replace the whole shebang if it still is too slow with the new disconnect.

Main jet will be set back to 118 (one jet higher than summer jet) for first trials.
Molto Verboso
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 1209
Location: London UK
Sat Jan 26, 2019 7:00 pm quote
Well that was lucky. All happened without an event. Not sure the quick connect is a good idea in a gravity feed. Pulling the pipe off the carb is not really so difficult, especially when the risk of low fuel flow threatens the integrity of the whole motor.

The good thing is the rules are still intact. 'if 3/4 goes better then WOT then the main jet is too small'
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Sat Jan 26, 2019 7:21 pm quote
Iím just happy I finally got off my butt and replaced the Cht sensor that died before this went down!
Hooked
Honda elite
Joined: 19 Jun 2007
Posts: 423
Location: California
Sun Jan 27, 2019 12:34 am quote
Jack221 wrote:
Well that was lucky. All happened without an event. Not sure the quick connect is a good idea in a gravity feed. Pulling the pipe off the carb is not really so difficult, especially when the risk of low fuel flow threatens the integrity of the whole motor.

The good thing is the rules are still intact. 'if 3/4 goes better then WOT then the main jet is too small'
interesting
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Sun Jan 27, 2019 7:04 am quote
The reason for the disconnect here is the small frame hose length is short or else prone to high spots. The first rule of unexpected high temps on a stable bike is still check fuel flow .
Ossessionato
1980 P200E, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 3677
Location: San Diego, CA
Sat Feb 02, 2019 2:12 pm quote
Time to flow 1 pt with new disconnect is 51s. Done.
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