my BLUE Bajaj fitting 60mm Crankshaft
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Ossessionato
1980 P200E , 2005 Stella 177
Joined: 20 Jul 2018
Posts: 2339
Location: Staten Island, NY
Sun Nov 08, 2020 9:32 am quote
haha thats what i was expecting... its a pancake of tire mount, tractor light mount and tractor light.

I kinda want one of those!
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Sun Nov 08, 2020 9:33 am quote
reminds me of a bed pan
Molto Verboso
79 P200E, 62 Allstate, 2008 Stella
Joined: 11 Jan 2006
Posts: 1819
Location: Florence, OR
Sun Nov 08, 2020 10:14 am quote
hibbert wrote:
reminds me of a bed pan
Heh heh... Thanks for the pics. It is pretty cool....
Molto Verboso
2007 Stella 150
Joined: 02 Nov 2019
Posts: 1258
Location: Rochester, Minnesota
Mon Nov 09, 2020 3:43 am quote
hibbert wrote:
Ok but tractor light
I like tractor lights for some reason. This could be my next spare with light. The tire holder would cover up the holes from the light I took off.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Mon Nov 16, 2020 12:30 pm quote
If I could get out of my own way I may get the Bajaj dialed in and tuned.

Stepping down the main jet is difficult for me. Dropped the main from 125 to 122 after changing to a BE5 atomiser and had been riding it around for a week or so. It was better less chunky but not perfect. Still something missing when cruising, closing the throttle and opening. Took it for a hundred mile spin for SWARM5 and took the Arroyo Parkway home again at 55mph. It felt OK but maybe too much vibration sensing something wasn't good enough.

Dropped the main again to 120. Oh my gosh different scooter. Changed like atomiser maybe better. Face hurts from smiling. Still something missing on the bottom so I broached the 52-160 pilot I made to 165. Hoping this alteration would be easily felt either right or wrong. Seems to be right. The 120MJ took out a major amount of vibration at higher RPM and made the scooter extremely more responsive throughout. I'm still smiling. The increase in pilot seems to have smoothed out the lack of response when opening and closing throttle. It sounds better when closed as well. Tried to see if the engine is quieter, think it might be in low speed, it just purrs along effortlessly now. Other thing scooter drives easier barely any throttle needed.

Think the game changer is the increase in float bowl passage to 2.0mm. At least seems like that was where the roadblock was in my set up. The raised float bowl did not seem to improve and may have added some unwanted variables.

29966456-EEC8-4421-B40F-7852B2BE79C4.jpeg
SWARM5

6229020C-BEB3-40CA-8C57-356D05D71626.jpeg
2nd gear WOT chop
52-165 pilot
2 1/2 turn air fuel mix
120AC BE5 120MJ
BR7HS spark plug

24FA5D21-A567-4806-A308-D0308F2DA238.jpeg
2nd gear WOT chop
52-165 pilot
2 1/2 turn air fuel mix
120AC BE5 120MJ
BR7HS spark plug

Enthusiast
2005 Stella 2T
Joined: 14 Jun 2020
Posts: 74
Location: MA
Mon Nov 16, 2020 1:19 pm quote
hibbert wrote:
Stepping down the main jet is difficult for me. Dropped the main from 125 to 122 after changing to a BE5 atomiser and had been riding it around for a week or so. It was better less chunky but not perfect. Still something missing when cruising, closing the throttle and opening. Took it for a hundred mile spin for SWARM5 and took the Arroyo Parkway home again at 55mph. It felt OK but maybe too much vibration sensing something wasn't good enough.

Dropped the main again to 120. Oh my gosh different scooter. Changed like atomiser maybe better. Face hurts from smiling. Still something missing on the bottom so I broached the 52-160 pilot I made to 165. Hoping this alteration would be easily felt either right or wrong. Seems to be right. The 120MJ took out a major amount of vibration at higher RPM and made the scooter extremely more responsive throughout. I'm still smiling. The increase in pilot seems to have smoothed out the lack of response when opening and closing throttle. It sounds better when closed as well. Tried to see if the engine is quieter, think it might be in low speed, it just purrs along effortlessly now. Other thing scooter drives easier barely any throttle needed.
Just had a similar experience myself. MJ120 was harsh at mid-rpms (no tach but guessing 4-6K) and then smoothed out again approaching WOT. Changed to MJ118 and now the motor is smooth as silk from 1/3 throttle on. Still chasing some low-rpm bogging though. Need some warmer weather before I can tackle that, but at least now I know the mainstack isn't drowning out the pilot jet circuit.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Mon Nov 16, 2020 1:54 pm quote
Keep at it Kowalski it is rewarding.

I am having one issue not sure about. When I do my plug chops in 2nd gear sometimes it will break up at the end. It's always in a higher RPM than I typically drive it. Not sure it is carburetion though almost feels like ignition. It's embarrassing when this happens on my street and have to "go again" and shut it down before breakup.

The chops aren't looking as clean as expected either so maybe there is still more leaning to be done.

31967098-907C-4B6D-9AE9-0CFAD5A4DB56.jpeg

C63F26F7-9C27-4C84-BBC8-920C284E51F7.jpeg

089BFA42-DB27-4E37-8E98-DF9E80D55C43.jpeg
2nd gear WOT chop
52-165 pilot
2 1/2 turn air fuel mix
120AC BE5 120MJ
BR7HS spark plug

Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Mon Nov 16, 2020 4:02 pm quote
If you have a BE4 you should try it now. Not that it might be better but to be sure it's worse. Although it might be better.

Guess if you ride it like this forever it would be fine but sounds like a few tweaks from perfection.

Igntion issues can cause a WOT rich feeling. Need to be really sure it's just jetting.
Molto Verboso
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 1844
Location: california
Tue Nov 17, 2020 9:52 am quote
Hebert
Curious - how are you running your "chops" before you are showing the plug?
Plug can be deceiving if you are idling or driving slower before you pull it as you get an "averaging" of throttle positions.
Generally - it looks quite good to me.
The ceramic is not sooty like after your SWARM ride - and you can feel and hear it really singing now.

The issue with it breaking up at the top - any chance you are running the float bowl dry? That can also give the symptoms you are describing.
Do you have a fast flow fuel tap on this build?
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Tue Nov 17, 2020 9:55 am quote
Got some test results. Popped in a BE4 and went for a ride. Seems rich all around a little 4 stroking off the line cleans up then sputter in high RPM. Didn't take long to analyze.

Dropped the BE5 back in and dropped the pilot to 50-160, wanting to see if the low rev issue would return but it seems to be good.

Gave the Chetak a good wring out and had break up again in high RPM. It's feeling almost like ignition, or misfire not exactly a backfire. Looked over my notes and remembered similar behavior when I was walking down the MJ on the BE3 so thought it could be a different symptom of richness maybe a different spectrum moving towards the need to be just a little leaner side? It's not sputter. Lately the scooter drives so good gotten used to driving more causal not pushing the envelope.

Nervously dropped the main jet to 118. Again less vibration good performance not as big of a jump from 122 to 120 but scooter wants to go faster and rides better. Can still create some breakup if riding above normal RPM range. I pulled it past 65 today and vibration felt like 40 and engine does not feel like it is getting tired. Now that the vibrations are going away higher speed is beginning to feel safer.

3436AA93-B368-4310-9BF7-BA3B61195501.jpeg

C466A1CF-E003-4721-B7C0-B8ED62E45E44.jpeg
2nd gear WOT chop
50-160 pilot
2 1/2 turn air fuel mix
120AC BE5 118MJ
BR7HS spark plug

F1EED6DF-00D9-4871-9DA6-31985FE1BF69.jpeg
2nd gear WOT chop
50-160 pilot
2 1/2 turn air fuel mix
120AC BE5 118MJ
BR7HS spark plug

D0E7F940-6661-4C7F-BDA4-45E6D4C9277D.jpeg
2nd gear WOT chop
50-160 pilot
2 1/2 turn air fuel mix
120AC BE5 118MJ
BR7HS spark plug

Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Tue Nov 17, 2020 10:12 am quote
Good points Charlie maybe my descriptions will uncover what is really going on. Or I may need to make a video. Could be jetting still not sure.

When I do a plug chop I will shift into 2nd then go WOT let the engine reach maximum RPM then hit the kill switch and pull the clutch leaving throttle open. Coast into driveway pull plug and photo.

Not sure about float bowl emptying maybe. Seems when I reduced the MJ to 118 break up occurs later or higher RPM and less of it. Also remember this behavior when I walked down the main jet on the BE3 after having reduced the pilot.

Another thing might be crank float? I can see the flywheel push out when revved and sink back in.
Molto Verboso
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 1844
Location: california
Tue Nov 17, 2020 10:18 am quote
^What fuel tap?
Stock or fast flow?

Plug read method seems pretty good.
Maybe a little better read with more load if possible in my experience - i.e. 3rd up hill.

Your 118 is using a bit less fuel.
If you are running dry at WOT - it might lessen with smaller main like that.
Of course it could be something else...
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Tue Nov 17, 2020 10:26 am quote
charlieman22 wrote:
^What fuel tap?
Stock or fast flow?

FAST FLOW

Plug read method seems pretty good.
Maybe a little better read with more load if possible in my experience - i.e. 3rd up hill.

AGREED

Your 118 is using a bit less fuel.
If you are running dry at WOT - it might lessen with smaller main like that.
Of course it could be something else...
Same conclusion or lack of

If I hold the throttle open on the stand it will break up at XRPM right before it sounds like lift off past the power band not sure its running out of gas.
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Tue Nov 17, 2020 1:12 pm quote
Not sure you gave the BE4 a proper go. When richening the atomiser the main jet needs to be a few sizes smaller. As BE5 is not bad at 118 and the plug chop still looks not lean, the BE4 could probably go to 115 before WOT starts to run clean.

Fuel tap is ok as it is. When it's an issue there is no doubt.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Tue Nov 17, 2020 1:27 pm quote
You're right only gave BE4 2 miles. Thought it was more of an exercise than to try and make it work.

Seized on 115MJ BE4 and 52-120 pilot according to my notes 3 miles at 60mph on the freeway coming home from Charliemans.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Tue Nov 17, 2020 3:54 pm quote
May have had a fouled plug.

Dropped MJ to 116 and still would NOT rev out on stand. Seemed ignition cut out.

Got to thinking remember this occurring before after significant changes to the jetting. This might be the 3rd or 4th time same symptom.

Put in a fresh BR8HS that I had revs clean again on stand. 118MJ back in for test ride tomorrow.
Molto Verboso
62 VBB1T Round Tail W/ leaner sidecar
Joined: 26 Jan 2019
Posts: 1844
Location: california
Tue Nov 17, 2020 9:22 pm quote
Quote:
Seized on 115MJ BE4 and 52-120 pilot according to my notes 3 miles at 60mph on the freeway coming home from Charliemans.
Was that with the carb drilled to 2mm?
Jet Eye Master
PX221 Malossi, O tuned PX200 and some motorbikes
Joined: 14 Jun 2017
Posts: 2504
Location: London UK
Wed Nov 18, 2020 3:07 am quote
Is great keeping notes. Could turn out to be a good save. As CM1 said, drilling 2mm would make a difference here. Was the drilling after the seize?

If BE4 115MJ is a seize, then BE5 118MJ is about the same. With the new spark plug, up jet to splutter point again and work down. Always good to check. Can't be too careful here.
Molto Verboso
Vespa
Joined: 19 Jun 2007
Posts: 1221
Location: California
Wed Nov 18, 2020 6:50 am quote
seized before drilling carb should be richer now.
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