weber what if ?
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- Posts: 247
- Joined: Thu Oct 22, 2009 10:38 am
- model: 750 Paso
- year: 1986
- Location: Mildura ,Australia
Re: weber what if ?
The problem with the 750,(and I can only honestly refer to the 750 as I have no experience whatsoever with the 906),isn't so much the duration of the fuel the pump supplies,it is the fact that it starts supplying far too much fuel,far too early,to an already rich enviroment and floods the engine,like leaving your choke on full,so you go from an idle that is correct mixture to trying to accelerate with your choke on with a warm engine,farting,missing,and no grunt,until the engine gets to the revs where it can handle the excess of fuel and starts to accelerate nicely,about 3500 to 4000 rpm.
I'm not trying to discredit Higgy or Romus in any way with the following comment but here is some food for thought:
All the information I have found says that a larger size Auxillary Ventury ,decreases the vacuum and delays the start of the main circuit.This would supply less fuel at this already rich stage of operation. This was one of the things that had me confused as to why the larger venturies were helping a lean spot ?,I don't think they were,I now believe that they were helping lean a rich spot,caused by the over supply of fuel from the cam.Thus smoothing low speed operation.If this is the case,then prevention is better than cure and cheaper too ! Jay.
I'm not trying to discredit Higgy or Romus in any way with the following comment but here is some food for thought:
All the information I have found says that a larger size Auxillary Ventury ,decreases the vacuum and delays the start of the main circuit.This would supply less fuel at this already rich stage of operation. This was one of the things that had me confused as to why the larger venturies were helping a lean spot ?,I don't think they were,I now believe that they were helping lean a rich spot,caused by the over supply of fuel from the cam.Thus smoothing low speed operation.If this is the case,then prevention is better than cure and cheaper too ! Jay.
Re: weber what if ?
Has anyone considered extending the auxiliary venturis with a bit of copper or brass tubing ? Dumb idea ?
Occupants of my Island of misfit toys:
'00 MG Quota, '97 MG Daytona RS, '87 MG Lemans SE, '75 MG 850 T, '69 MG Ambassador, '96 Triumph D1200, 91 Duc 907 IE
1986 Guzzi BOTT Racer
'00 MG Quota, '97 MG Daytona RS, '87 MG Lemans SE, '75 MG 850 T, '69 MG Ambassador, '96 Triumph D1200, 91 Duc 907 IE
1986 Guzzi BOTT Racer
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- Posts: 247
- Joined: Thu Oct 22, 2009 10:38 am
- model: 750 Paso
- year: 1986
- Location: Mildura ,Australia
Re: weber what if ?
Yes,but then I thought of the potentially disasterous results should one dislodge.I then found out how they work,and it is not so much the height of the ventury but the restriction on the inside at the height of the tubes feeding across to the main jets that creates the vacuum (ventury)effect that pulls the fuel up from the emulsion tube well.All of the information available will tell you that the smaller size ventury creates more vacuum thus starting the main jet sooner,and fitting a larger ventury will create less vacuum and delay the start of the main jet,which is detrimental to covering the lean hole further up the rev range,but might help down low by supplying less fuel.If this is in fact what is happening on the 906 (I know that this is what is causing a problem on the 750),by fitting the larger ventury,wouldn't it make more sense to add less fuel with the accelerator pump than to try and fix the problem by fitting hard to source expensive venturies that may cause more problems further up the rev range? Jay.
- higgy
- paso grand pooh-bah
- Posts: 3332
- Joined: Tue Jul 29, 2008 9:50 pm
- model: 907 I.E.
- year: 1992
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Re: weber what if ?
All the information I have found says that a larger size Auxillary Ventury ,decreases the vacuum and delays the start of the main circuit.This would supply less fuel at this already rich stage of operation. This was one of the things that had me confused as to why the larger venturies were helping a lean spot ?,I don't think they were,I now believe that they were helping lean a rich spot,caused by the over supply of fuel from the cam.Thus smoothing low speed operation.If this is the case,then prevention is better than cure and cheaper too ! Jay.
Many routes to the solution, I have no disagreement with yours,in the end yours may be the most effective solution.
I have as yet had no time to do anything about the pump cam and I do in fact have a lean issue over 100 mph I also have had no time to resolve.
To me it's not about who has the best solution or who gets credit.
Lets just find one that works for every one and as cheap as possible
Jayh, can't wait to read your document
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
- higgy
- paso grand pooh-bah
- Posts: 3332
- Joined: Tue Jul 29, 2008 9:50 pm
- model: 907 I.E.
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Re: weber what if ?
Hey,did you get an early release for good behaviour Higgy ?
No,just got home for a few hours after an 8 hour drive from Raleigh North Carolina.
Have to be in Lancaster Pennsylvania at 7am about a two hour drive.
Rumor has it I'll be in the New York area for a month or so after that.
got a speeding ticket in Virginia for 86 in a 60. Thought the limit was 70 and was eager to get home for a while I am told it will cost around 3500 Guess I worked last week for some Magistrate of the Commonwealth of Virginia's pet project
Long hard hours and not much sleep and 4 more months to go if it doesn't get an extention. Could go into the winter.. I am crying all the way to the bank
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
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- Posts: 247
- Joined: Thu Oct 22, 2009 10:38 am
- model: 750 Paso
- year: 1986
- Location: Mildura ,Australia
Re: weber what if ?
Yes you're right Higgy,it's all about making the Paso the best it can be, not who did what and when
Was that a typo. or is the fine $3500.00 F*CK ME that's expensive,you'd be lucky to pay that for running over a little old lady and killing her in Australia.Don't they like tourists in Virginia or something or did you give the cuntstable some lip service ? Jay.
Was that a typo. or is the fine $3500.00 F*CK ME that's expensive,you'd be lucky to pay that for running over a little old lady and killing her in Australia.Don't they like tourists in Virginia or something or did you give the cuntstable some lip service ? Jay.
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- paso grand pooh-bah
- Posts: 1878
- Joined: Wed Dec 05, 2007 12:35 am
- model: 906 Paso
- year: 1990
- Location: New Zealand
Re: weber what if ?
Or taking out a motocyclist... 4 grand in NZ, but yeah! F*CK ME TOOjayh wrote:Was that a typo. or is the fine $3500.00 F*CK ME that's expensive,you'd be lucky to pay that for running over a little old lady and killing her in Australia
I wish I was young again............Id be heaps smarter than last time
- higgy
- paso grand pooh-bah
- Posts: 3332
- Joined: Tue Jul 29, 2008 9:50 pm
- model: 907 I.E.
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- Contact:
Re: weber what if ?
no typo 3500.00 is what I am told
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
-
- paso grand pooh-bah
- Posts: 1878
- Joined: Wed Dec 05, 2007 12:35 am
- model: 906 Paso
- year: 1990
- Location: New Zealand
Re: weber what if ?
Wow , I guess 26.. ...hang on a minute , are we talkin KPH or MPH ?
I wish I was young again............Id be heaps smarter than last time
- higgy
- paso grand pooh-bah
- Posts: 3332
- Joined: Tue Jul 29, 2008 9:50 pm
- model: 907 I.E.
- year: 1992
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- Contact:
Re: weber what if ?
The posted limit was 70mph, traffic was doing 85, talkin trucks. I set the cruise control for 83 figuring I was safe and then kept my eye on the deer population, silly me, now not to make excuses but I had not seen my wife and family in 7 weeks and I had a limited chance to go home...I took it
I did talk to a lawyer today, she wants a grand to go " beg " on my behalf, which means I have to post 2500 in fines and her grand, so yes kiss the 3500 I took home last week good bye !!!!
Least I got laid
Got a copy of my driving record today, no tickets in a long long time. 9 years at least
They tell me if it had been in N Carolina where I started I'd still be in jail.
Just me and a cop and the dear...no one else
I did talk to a lawyer today, she wants a grand to go " beg " on my behalf, which means I have to post 2500 in fines and her grand, so yes kiss the 3500 I took home last week good bye !!!!
Least I got laid
Got a copy of my driving record today, no tickets in a long long time. 9 years at least
They tell me if it had been in N Carolina where I started I'd still be in jail.
Just me and a cop and the dear...no one else
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
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- Posts: 10
- Joined: Wed Jun 08, 2011 9:59 pm
- model: 750 Paso
- year: 1988
- Location: Houston ,Texas
Re: weber what if ?
Hey Higgy.... You might want to get ahold of the prosecutor and see if you can take a Defensive Driver course and pay a smaller fine. Works for most people....here in Texas at least. I for one am not "allowed" to take DD course to keep traffic violations off my record because I have a Class A CDL. They figure I should know better
Also if the actual "posted" limit was 70mph and the ticket reads you were in a 60mph zone (as you said in an earlier post) then the ticket was written wrong and will be thrown out if you push the issue.
Also if the actual "posted" limit was 70mph and the ticket reads you were in a 60mph zone (as you said in an earlier post) then the ticket was written wrong and will be thrown out if you push the issue.
- higgy
- paso grand pooh-bah
- Posts: 3332
- Joined: Tue Jul 29, 2008 9:50 pm
- model: 907 I.E.
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- Contact:
Re: weber what if ?
Already have a lawyer on it,She wants another grand
I think I;ll just stay out if Virginia,FU
I think I;ll just stay out if Virginia,FU
Ducati,making mechanics out of riders since 1946
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
There's no problem so bad that a little fixing can't make it worse! : )
If it ain't broke keep fixin it till it is
88 750
90 906
92 907ie
-
- paso grand pooh-bah
- Posts: 1878
- Joined: Wed Dec 05, 2007 12:35 am
- model: 906 Paso
- year: 1990
- Location: New Zealand
Re: weber what if ?
Wow ! thats some lawyer, still for a grand you'd expect ithiggy wrote: Least I got laid
I wish I was young again............Id be heaps smarter than last time
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- Posts: 247
- Joined: Thu Oct 22, 2009 10:38 am
- model: 750 Paso
- year: 1986
- Location: Mildura ,Australia
Re: weber what if ?
Sorry about the delay,here's a couple of rough drawings to get you started if you can't be bothered waiting for my neat version.The measurements I have included should be a 'Safe version' that can be confidently filed away in one go as they are 2mm less than mine.You can always take a bit more off if you feel you need it.Better to be safe than sorry !.
Take note of any missing when you first start riding in the 2000-3000 rpm range.
If the missing gets worse when the bike warms up,or there is no missing cold but you develop a miss as the bike warms up,it is a rich miss and you can take more off the cam.Just a little bit !
if the miss gets better as the bike gets warm or disappears entirely it is a lean miss,don't take any more off the cam !
I used a flat file and filed parallel with the back face of the cam to create a longer flat at the start of the cam and then put the file on the same angle as the ramp and filed that back to match the extended start,but this left a little v spot where the ramp started,so I got a half round file and carefully filed a little bit of a radius to smooth this spot and extended the radius up the ramp,the photo shows this clearly.
Take note of any missing when you first start riding in the 2000-3000 rpm range.
If the missing gets worse when the bike warms up,or there is no missing cold but you develop a miss as the bike warms up,it is a rich miss and you can take more off the cam.Just a little bit !
if the miss gets better as the bike gets warm or disappears entirely it is a lean miss,don't take any more off the cam !
I used a flat file and filed parallel with the back face of the cam to create a longer flat at the start of the cam and then put the file on the same angle as the ramp and filed that back to match the extended start,but this left a little v spot where the ramp started,so I got a half round file and carefully filed a little bit of a radius to smooth this spot and extended the radius up the ramp,the photo shows this clearly.
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- Posts: 192
- Joined: Sun Jul 24, 2011 1:57 pm
- model: 750 Paso
- year: 1988
- Location: delta b.c. canada
Re: weber what if ?
i just got mine running i have not done much tuning yet. but my brother helped me to get it back on the road. he is a 35 year mechanic with quite a bit of weber car experence. when he looked at the weber he siad right away that he felt the amount of availible float drop was not enough he adjusted the float drop and we did some basic air flow meter balencing of the carb & adjusting. i am not experiencing the weber flat spot/bog. i am not an expert by anymeans.just thought i would throw it out there for your info