weber what if ?

discussions specific to the 750 Paso

Moderators: paso750, jcslocum

User avatar
Brutus
Posts: 257
Joined: Sun Jan 16, 2005 12:00 am
model: 750 Paso
year: 1989
Location: The Netherlands

Re: weber what if ?

Post by Brutus »

:cool:
Last edited by Brutus on Thu Jun 04, 2015 7:10 pm, edited 2 times in total.
_________________
Better too late than too ugly..
User avatar
Brutus
Posts: 257
Joined: Sun Jan 16, 2005 12:00 am
model: 750 Paso
year: 1989
Location: The Netherlands

Re: weber what if ?

Post by Brutus »

Now I noticed a couple of things. Below the three measurements in digits. Looking at the AFR during the two runs on the freeway (+100km/u) it shows an average of 14,53 AFR between 4000 and 5600 RPM. Between 800 and 4000 RPM it shows an average of 13,2 AFR, a bit richer. Above 6400 RPM it's around 15,35 AFR, a bit leaner.

The measurements off freeway (50-100 km/u) gives slightly different results. Now it shows an average of 13,65 AFR between 4000 and 5600 RPM. Between 800 and 4000 RPM it shows an average of 13,56 AFR. Didn't go above 6400 RPM off freeway.

Conclusion so far is that it is only running stoichiometric on the freeway between 4000 and 5600 rpm. This should be at the time the mains are functioning 100% and the idle jet isn't activated. On the other hand it's a bit rich below 4000 rpm. Also it feels lazy when going from low to higher revs. Doesn't react instantly on the throttle..

Like to hear any suggestions where to go from here.
Léon
Attachments
foto1_7 Sessie6_tabel.jpg
foto1_7 Sessie6_tabel.jpg (147.41 KiB) Viewed 3040 times
foto1_8 Sessie8_tabel.jpg
foto1_8 Sessie8_tabel.jpg (167.81 KiB) Viewed 3040 times
foto1_9 Sessie10_tabel.jpg
foto1_9 Sessie10_tabel.jpg (130.34 KiB) Viewed 3040 times
_________________
Better too late than too ugly..
User avatar
Brutus
Posts: 257
Joined: Sun Jan 16, 2005 12:00 am
model: 750 Paso
year: 1989
Location: The Netherlands

Re: weber what if ?

Post by Brutus »

Gents, in the last couple of days I've tried different setups. Got back to idle 65 main 145 and AC 170. Below you can see the result. Rather rich overal with some stumble around 3k. Surprisingly the engine reacts a lot better than the 56/165/185..
idle65_main145_AC170.jpg
idle65_main145_AC170.jpg (121.9 KiB) Viewed 2964 times
Due to the bike response it seems I'm on the right path here. Changing the idle doesn't make a lot of sense as the AFR is rich overall.. I was wondering what should happen if I only adjusted the AC. Theoreticly it should give air during idleing and in higher revs. Below the setting 65/145/175. The AFR is a bit leaner then with the 170 AC's:
idle65_main145_AC175.jpg
idle65_main145_AC175.jpg (119.44 KiB) Viewed 2964 times
This morning I tried 60/145/175. I have to say that the bike is stonecold during the testlap, while the two above were done with a hot engine. The rich stumble at 3k is allmost gone. Maybe when driving it really warmed up, it wouldn't be noticable at all.
idle60_main145_AC175.jpg
idle60_main145_AC175.jpg (151.81 KiB) Viewed 2964 times
To be continued..!
_________________
Better too late than too ugly..
Post Reply