No, I appreciate the information, don't stop that. I need & appreciate the info Dennis..
On Mar 9, 2009, at 2:17 AM, Dennis Hammerl wrote: > I guess I talk some other language. sorry. > I'll try to be VERY specific in some future post. Like arrows and > drawings, detailed pictures and NO MORE information. I don't need a > computer to talk to myself. > ' > > --- On Sat, 3/7/09, Graham Rogers <[email protected]> wrote: > From: Graham Rogers <[email protected]> > Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem > To: [email protected] > Date: Saturday, March 7, 2009, 10:16 PM > > I did buy the 650. I've never seen pipes like it they are mint and > I put them on a 650 with rusted pipes. A friend wants the engine > and I get a lot of good spare parts. The generator/alternator, > whatever the CB650SC has, is shot on it. The rest is good. > > Okay so my CB750 problem is not lack of fuel supply through the > petcock because choking 'solves' the problem. What do you mean by > 'slow speed circuit'? - the idle jets? > > On Mar 7, 2009, at 10:01 PM, Dennis Hammerl wrote: > >> GRAB THAT 650 ! The pipes alone will return much more than $200. >> If your "valve" couldn't supply enough fuel, no amount of choke >> would make up for it. duh >> The choke gets it's supply from the same bowl... >> Now, a further lesson. A motorcycle carb has many stages and they >> are ADDED as RPM increases. Without the fuel from the blocked slow >> speed circuit, all stages are too lean. If it "went to bed" above >> 5k, the problem would be at the high speed circuit. Bear in mind >> that bikes of that period (late 70's~early 80's) were just flat >> too lean to start with (blame the EPA compliance / CARB standard) >> any congestion becomes critical. An increase to #37 of the slow >> jet makes them run a good bit better. Now, contrary to popular >> belief, "if some's good, more's better" does not apply. A #40 slow >> jet makes for poor running. Jet numbering is a percentage of 100. >> A #35 supplies 35% as much as a #100. >> >> --- On Sat, 3/7/09, Graham Rogers <[email protected]> wrote: >> From: Graham Rogers <[email protected]> >> Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem >> To: [email protected] >> Date: Saturday, March 7, 2009, 2:08 AM >> >> Thanks Dennis, I ran my own 'petcock' system (a plumbing shut off >> valve) from the tank when I couldn't find a good stock petcock for >> a CB750F so I'll start there. The breaking up happens at any >> speed when the choke is not on. I'll get back to my CB700 when >> I've got this one ready to sell. By the way I came across a 1983 >> CB650SC last week real cheap ($200) to use as parts for another >> one I have. This parts bike has pipes in mint condition and I'm >> hoping anything else I'll need for my CB700 (the N/gear indicator >> problem) I can get from the CB650. >> >> On Mar 7, 2009, at 12:34 AM, Dennis Hammerl wrote: >> >>> So, we switch bikes ? OK, this one sounds like clogged slow speed >>> circuits. "Breaking up" (is hard to do ?) is a lean condition. >>> Rich mixtures are just sluggish, lean ones crackle and pop. >>> Again, check jet sizes. 1980 CB750F should be; primary 68, >>> secondary 102, slow 35. >>> Now for all the tuners; you can over jet so much that the result >>> is just like being too lean. The air velocity is too slow at low >>> engine speeds that it doesn't carry that much fuel in. >>> snap-crackle-pop. and then.... WHOOSH as it hits an engine speed >>> that can make it all work. When it all works like it should, >>> things are sooo boring. They start and run, pull from low engine >>> speeds and go pretty good. If rejetting is ever indicated >>> following an exhaust change, start with a base-line of stock >>> jetting and correct as necessary. Inspite of "enclosed >>> instructions" most after market exhaust systems require only >>> slight changes to jetting if any at all. >>> >>> --- On Fri, 3/6/09, Graham Rogers <[email protected]> wrote: >>> From: Graham Rogers <[email protected]> >>> Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem >>> To: [email protected] >>> Date: Friday, March 6, 2009, 7:59 AM >>> >>> This bike CB700) is on hold for a little bit. I'm having to make >>> the difficult decision to sell one of my Hondas. So I'm going to >>> sell my 1980 CB750F. But first I have a problem. I restored this >>> bike as much as I can (paint job, new decals, new seat cover and >>> detailed clean, including carbs). The bike runs good as long as >>> I keep the choke on some. The bike breaks up and dies if I do not >>> use the choke. Here's what I suspect may be the problem and this >>> is where I need help. I could not find a vacuum leak by spraying >>> around the carbs while it was running. The bike has a 4 into 1 >>> exhaust system. That's how I got it. Should the carbs have been >>> modified/adjusted for the change from the original exhaust system >>> and had they not, would that cause it to run lean and so need >>> the choke activated? If that's the case what do I need to do? >>> Installing stock exhausts/mufflers is too expensive. Thanks >>> guys, Graham >>> >>> On Feb 26, 2009, at 12:38 AM, Dennis Hammerl wrote: >>> >>>> They are your carbs. Investigate what passages are blocked. It >>>> would seem that you have sufficient intake vacuum, Hand choking >>>> increases that. If all was well, after hand choking, the plugs >>>> would be saturated. Because they aren't, the path from bowl to >>>> intake via choke valves must be blocked or the choke valves >>>> don't work properly. They can be removed without too much >>>> trouble. Very simple devices. >>>> >>>> --- On Wed, 2/25/09, Graham Rogers <[email protected]> wrote: >>>> From: Graham Rogers <[email protected]> >>>> Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem >>>> To: [email protected] >>>> Date: Wednesday, February 25, 2009, 5:46 PM >>>> >>>> I cranked the motor over - it tried to start, at least on one >>>> or two cyl. Then I checked the plugs. They were dry on the tips >>>> and porcelain but a little wet on the rim of the plug. It >>>> didn't smell like gas however. I then tried to start the bike >>>> with my hand restricting the air flow at the air filter. It did >>>> start but died when I moved my 'hand choke' I probably could >>>> have gotten it started that way. So, it looks like the choke >>>> isn't working eh? Now what? >>>> Graham >>>> >>>> On Feb 25, 2009, at 12:21 AM, Dennis Hammerl wrote: >>>> >>>>> Spraying it optimizes the conditions needed for starting. >>>>> Which... means the chokes aren't working. If it has a strong >>>>> vacuum when cranking if you hold your hand over any carb >>>>> throat, the chokes aren't passing any fuel. WHY ? The "gas >>>>> chokes" are very simple valve devices. If they have access to >>>>> fuel from the float chamber and they are open to the bores when >>>>> activated, all should work. With the throttle plates closed, >>>>> the high vacuum (or , more properly, low pressure) should draw >>>>> fuel up through the choke circuits and into the motor. It's as >>>>> simple as a faucet. I don't want to get into any abstract at >>>>> this point. Are the plugs getting wet when you crank the motor >>>>> with the chioke operated ? Knowing that is a must before >>>>> proceding. If they are, we look elsewhere. If not, we stay in >>>>> the carbs. >>>>> >>>>> --- On Tue, 2/24/09, Graham Rogers <[email protected]> wrote: >>>>> From: Graham Rogers <[email protected]> >>>>> Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem >>>>> To: [email protected] >>>>> Date: Tuesday, February 24, 2009, 8:05 AM >>>>> >>>>> Tried starting the bike this morning and there doesn't seem to >>>>> be any improvement. It would 'bubble' along like it was trying >>>>> to catch (it acted like a weak spark) but again it took >>>>> starting fluid and the choke seemed not to play apart. Once it >>>>> had 'caught', restricting the air flow through the air filter >>>>> with my hand significantly increased the rpms. Maybe I should >>>>> also check the state of the battery huh? >>>>> Incidently I noticed the fuel gauge didn't work until I revved >>>>> the engine significantly and held the revs. That was a new one >>>>> to me, Graham >>>>> >>>>> On Feb 23, 2009, at 11:02 PM, Dennis Hammerl wrote: >>>>> >>>>>> Let us know how that works out. The neutral wiring is grounded >>>>>> and that's why it always shows N / green light. Let's get into >>>>>> that later. You have multiple issues. One at a time. >>>>>> >>>>>> --- On Mon, 2/23/09, kiwi <[email protected]> wrote: >>>>>> From: kiwi <[email protected]> >>>>>> Subject: [Nighthawk Lovers] Re: Nighthawk S starting problem >>>>>> To: "Nighthawk Motorcycle Lovers!" >>>>>> <[email protected]> >>>>>> Date: Monday, February 23, 2009, 1:16 PM >>>>>> >>>>>> Blasted those tiny holes that allow the gas through when using >>>>>> the >>>>>> choke with >>>>>> compressed air and >>>>>> spent 2 hours reinstalling the carbs. It >>>>>> still took starting fluid to get the bike started BUT, not >>>>>> very much >>>>>> and the choke worked a little. I'll see how it starts >>>>>> tomorrow when >>>>>> it is back to winter temperature. >>>>>> Second problem with this NH is the neutral/gear indicator. It >>>>>> reads N >>>>>> all the time and won't show what gear the bike is in. I >>>>>> found a little >>>>>> black box under the tail section that I think is part of the N/ >>>>>> gear >>>>>> indicator system. Is there a way to check it? >>>>>> Third problem should be >>>>>> simple. The left front turn signal is >>>>>> 'bright' when ignition is on but will not blink when it >>>>>> should. The >>>>>> others work as they should. That left one shines a lot brighter >>>>>> than >>>>>> the right front when ignition is on. >>>>>> >>>>>> On Feb 22, 11:11 pm, Dennis Hammerl <[email protected]> wrote: >>>>>> > I will assume your carb clean was a complete operation. >>>>>> Let's examine >>>>>> how the choke works. The cable >>>>>> opens valves that will >>>>>> permit raw fuel to be >>>>>> sucked into the motor during cranking. Now, lets say that >>>>>> works fine.Your plugs >>>>>> should be wet after cranking for a short while. Y-N ? The most >>>>>> common >>>>>> cause of >>>>>> the plugs being dry after cranking is the throttle plates >>>>>> being open too far and >>>>>> causing insufficient vacuum. Same as opening the throttle >>>>>> while trying >>>>>> to start. >>>>>> When the intake air flow is too low, no fuel will be drawn in >>>>>> from the choke >>>>>> circuit. If the plugs are wet, you're flooding the motor. >>>>>> > We start >>>>>> here. Additional checks of compression and a leak-down may be in >>>>>> order. >>>>>> > This may take time to resolve. Get at it. >>>>>> > >>>>>> > --- On Sun, 2/22/09, >>>>>> Graham Rogers <[email protected]> wrote: >>>>>> > From: Graham Rogers <[email protected]> >>>>>> > Subject: [Nighthawk Lovers] Nighthawk S starting problem >>>>>> > To: [email protected] >>>>>> > Date: Sunday, February 22, 2009, 6:18 PM >>>>>> > >>>>>> > I have a 1986 Nighthawk S. It ran before I got it but >>>>>> always took >>>>>> > starter fluid in the air filter to get it going. I pulled >>>>>> the carbs >>>>>> > and >>>>>> thoroughly cleaned them and used to compressed air in all the >>>>>> > >>>>>> holes. However the bike still will not start without stater >>>>>> fluid >>>>>> > and even then it takes along time with the fluid. I noticed >>>>>> that >>>>>> > >>>>>> using the choke seemed to make no difference at all so, >>>>>> thinking that >>>>>> > perhaps the choke isn't working at all I removed the carbs >>>>>> again >>>>>> > >>>>>> (they are terrible to remove) and did what I could toi ensure >>>>>> the >>>>>> > choke was working right. The mechanism moves as it should >>>>>> and I used >>>>>> > compressed air in the holes to the where >>>>>> I >>>>>> presume the choke opens. >>>>>> > Now, before I reinstall the carbs, any suggestions? Could the >>>>>> > problem have been the choke or is there something else that >>>>>> would >>>>>> > cause the same problem. By the way, once the bike was >>>>>> warmed up, it >>>>>> > ran fine - just when it's cold I have to use >>>>>> starting fluid, Graham >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >>> >>> >>> >>> >>> >> >> >> >> >> >> >> > > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
