I had a problem with a rough idle after I got my Hawk too. I put new carbs on it and still had a problem. I found out that it was tiny particles that still lingered in my tank and gas line, even after I cleaned my petcock and screen. I just ran it with Seafoam and sprayed my carbs out with carb cleaner until eventually it ran smooth again. I don't know if that's your problem exactly but I would be suspicious of it considering the condition of your petcock. Keep us informed....HotrodMamma. ----- Original Message ----- From: Joel Kelly To: [email protected] Sent: Friday, May 29, 2009 4:31 AM Subject: [Nighthawk Lovers] Re: How responsive is a 1983 750sc NH?
I didn't think it was a smart a$$ comment. There was an air leak in the second rubber boot from not being seated correctly... when I cleaned the carbs. Now they are good... I haven't checked plug wires and valve clearance yet. I rebuilt the petcock and found the most rust I have ever seen in one. The bike responds way better, but with a bit of a rough idle.... I will check the mainfold tomorrow when i wake up.The issue is I have no clue on what originally this bike needs to sound like... it could be my MAC exhaust.... that thing rattles a high rpm's... maybe there is a restricting issue there. Thanks for all your help so far. I have decided I don't like MAC exhaust. On Wed, May 27, 2009 at 10:13 PM, Dennis Hammerl <[email protected]> wrote: Sorry for a smart-a## reply but you seem to have all the answers. And the questions. If the carbs are as clean as you say and everything is OK, how can you have a problem ? I don't have a crystal ball, I'm not there and all I know about your situation is what you tell me. The condition you describe is a very lean one. That means #1 blocked slow speed circuits, #2 air leak at ?? #3 very tight valve lash settings, or whatever. Get it to idle (you can get it to do that ?) and spray carb cleaner around the intake manifolds. any effect ? that's the check for air leaks. There probably isn't a Honda dealer with the tools and shims to adjust valves on one of those after all these years but you can check clearances. .003" intake, .004" exhaust. Because of the high cost of that operation, most haven't been done in eons. you checked advance ? At idle and at 2000RPM ? That's the check for advancer operation. Spark jumps a gap of at least 10MM before failing ? All plug wires ? --- On Wed, 5/27/09, [email protected] <[email protected]> wrote: From: [email protected] <[email protected]> Subject: [Nighthawk Lovers] Re: How responsive is a 1983 750sc NH? To: "Nighthawk Motorcycle Lovers!" <[email protected]> Date: Wednesday, May 27, 2009, 6:20 AM OK..... checked ignition timing.... All good there.... did plugs again and GAPPED correctly...LOL.... put Seafoam in with gas...premium of course and it ran way worse than before..... about 40km(27mi) I stopped at a friends house to meet up for a ride and noticed some sort of condensation at the bottom of the petcock.... it was gas..... My only thought is that the seafoam cleaned out the tank and the debris clogged it. I will look at it later today, but the performance has gotten worse..... instead of issues of the top end ... I know have the opposite LOL..... when it takes off it sounds inconsistent and exhaust "pops" a lot with a whistling sound for a brief moment after it "pops" I seem to be misfiring more than ever now. Also the bike is jerky on take off. I rode the bike another 45km(30mi) and it never got better. Looked at carbs again and they are squeaky clean and jets are clean and no obstructions I see. Any thoughts? On May 17, 5:31 am, "[email protected]" <[email protected]> wrote: > SON OF A SEA BISCUIT...... The book is in canadian metrics and I > adjusted for USA standard cause I am so used to that being I am from > the states. YOU ARE RIGHT..... I am such a bone head.... thanks for > clearing that up for me. I will go fix it now. > > On May 16, 11:00 pm, Dennis Hammerl <[email protected]> wrote: > > > > > why are you playing around with the cam chain tensioner ? I suggested you check the ignition advancer. Oh well. Your carb job is waiting. > > > --- On Sat, 5/16/09, [email protected] <[email protected]> wrote: > > > From: [email protected] <[email protected]> > > Subject: [Nighthawk Lovers] Re: Howresponsiveis a 1983 750sc NH? > > To: "Nighthawk Motorcycle Lovers!" <[email protected]> > > Date: Saturday, May 16, 2009, 9:09 PM > > > OK, I just got back from my ride and it still lacks power... 1 gear > > takes off... good acceleration, 2nd and 3rd is good as well, but when > > I get to around 4000 RPM's in 4th it loses umph, and 5th is worse > > around the the same RPM's up to around 5700. I know it's running rich > > cause I went 146 km (91 miles) and had to kick over to reserve. I > > tried manually adjusting the cam chain tensioner. I noticed nothing > > and honestly I am clueless. When the bike cools down I am going to > > check the plugs for carbon build up... Does anyone have any more > > suggestions? I let the previous owner ride it and he confirmed that it > > lacked power.... A bit disappointed at the moment. > > > On May 16, 1:11 pm, Kyle Munz <[email protected]> wrote: > > > > No fuss raised on my part, I was just curious. They made a CX500T back in > > > the day that was one of the very few factory turbocharged bikes, that would > > > definitely hang with faster bikes. I believe it was fuel injected rather > > > than carbureted tho, and had a plastic fairing and TURBO logos all over it. > > > I've had several turbo cars and really miss that whine, I'd love one of > > > those turbo bikes but at this point I'd probably get in trouble for having > > > another bike in the garage. I need a bigger garage ;) > > > > -Kyle > > > > On Sat, May 16, 2009 at 11:44 AM, Biz Account <[email protected]>wrote: > > > > > Honestly Kyle I don't know... I picked it up for 300 back in college and > > > > was just happy to have the bike... When I got it.. It was in rough shape and > > > > waterpump housing broke about a week later. Fixed it with my uncle at his > > > > shop. It wasn't until I moved with that roommate that it reached it's full > > > > potential.. The first week I was there he took apart my bike. He was the > > > > type of person who took everything apart and made it better. He was super > > > > excited to see the bike and called it one of a kind. He taught me a ton > > > > about bikes and lots of other things. The neighbor across the street was a > > > > machinist and my roommate had him make parts. We jetted the carbs, but he > > > > did it a totally different way compared to the kits I see now days... I am > > > > not sure what to tell everyone.... I was there and it performed excellent > > > > and impressively.... I am sorry my statement raised such a fuss with > > > > everyone on the performance part. My sincere apologies > > > > > Sent from my iPhone > > > > > On 16-May-09, at 9:17 AM, Kyle Munz <[email protected]> wrote: > > > > > This CX500 wouldn't happen to have a "T" after the model numbers would it? > > > > > -Kyle > > > > > On Sat, May 16, 2009 at 4:48 AM, <[email protected]> > > > > [email protected] < <[email protected]> > > > > [email protected]> wrote: > > > > >> The pipes are all hot and I found carbon on the first spark plug, but > > > >> not the other three. Cleaned with wire brush and regapped... gapped > > > >> them all to .65 and it seemed to have less of an issue misfiring, but > > > >> not before the changing the oil with some nicer stuff. I made a rookie > > > >> mistake in trusting previous owner when said changed the oil. The oil > > > >> was thick and blackest I have ever seen. Was going to give it a good > > > >> ride later today and see if my bike had improved performance. If not I > > > >> was going to check the ignition timing. The sound I am getting for > > > >> lack of anything better to compare it to is walking up a couple wood > > > >> stairs, but it's not consistent and you have to listen for it a bit. > > > >> As far as the CX500 thing.... All I can say is when I got it.... it > > > >> was gutless, but after my roommate and I mostly him got done.... It > > > >> was agile, quick, and I never had issues staying on his tail. Thanks > > > >> for all your help so far.... It helped me a great deal on friday when > > > >> I was ripping things apart checking things. > > > > >> On May 15, 10:56 pm, Dennis Hammerl <[email protected]> wrote: > > > >> > Yes on the HOT to the touch deal. Now if YOU did the carb clean, did you > > > >> remove and clean under those black rubber plugs ? Seems like most people > > > >> miss those. The mechanical advancer is on the end of the crankshaft. They > > > >> can stick in a closed position and not advance properly. Just something to > > > >> check on. The "pop" thing is a too lean condition. > > > >> > A CX500 that runs with a CBR600 ? NOx wouldn't do that. That's one story > > > >> I can't swallow. For as much as some may think I love Honda's, I have only a > > > >> short list of great ones and the CX doesn't make it. Their only saving grace > > > >> is longevity. I've seen them with over 80k and still running. > > > > >> > --- On Fri, 5/15/09, [email protected] < > > > >> [email protected]> wrote: > > > > >> > From: [email protected] <[email protected]> > > > >> > Subject: [Nighthawk Lovers] Re: Howresponsiveis a 1983 750sc NH? > > > >> > To: "Nighthawk Motorcycle Lovers!" <<[email protected]> > > > >> [email protected]> > > > >> > Date: Friday, May 15, 2009, 1:16 AM > > > > >> > I will give you as much info as I can. I cleaned one carb at a time. I > > > >> > took it for a long ride opened it up a bit and tryying to clear out > > > >> > anything remaining. It was a bit quicker towards the end of the ride. > > > >> > It seemed to be a lot quicker after higher RPM's. Once it got over > > > >> > that hump... it started moving quite a bit faster. The exhaust was a > > > >> > bit "poppy" for lack of better word when I would roll on aggressively. > > > >> > I haven't checked the cylinders yet. Was hoping not to have to dive in > > > >> > so early in the season. I have heard that if I touch the pipes on the > > > >> > manifold and they are not all hot, I have a cylinder issue... Is this > > > >> > true? I am not sure what an advancer is so if I can get more of an > > > >> > explanation of this, I would appreciate it. I will also check the > > > >> > venting tubes and make sure there in the right direction. In all > > > >> > fairness about the CX500. My roommate and I tuned it to keep up with > > > >> > his 93 cbr 600 f3. Anyways... I very much appreciate the wisdom as I > > > >> > am new to the Nighthawks and can use all the help I can get. > > > > >> > On May 14, 9:36 pm, Dennis Hammerl <[email protected]> wrote: > > > > >> > > On such a small amount of info, I can only speculate a few things. > > > >> First off, I can't verify the quality of work done by any other source. That > > > >> bike has a mechanical advance. I'd Check to make sure it is functional. Your > > > >> symptoms sound like an advancer that is stuck. Another item is the > > > >> accelerator pump. When you did the carbs, did you do all at once or one at a > > > >> time ? From your riding position, all vacuum caps should face you ( the > > > >> printing readable, not upside down) Getting those wrong will cause throttle > > > >> response problems. To compare it to a CX500 is a travesty. A CB750C should > > > >> be able to tow one of those faster than it could go on it's own. One final > > > >> question, does it even run on all four ? (hint; you can sync carbs on a bike > > > >> that has dead cylinders) A two cylinder 750 would run worse than a CX500. > > > >> > > Check for all four, get a timing light and check for advance, look for > > > >> discharge from accelerator pump. Most techs at dealerships today have little > > > >> / no experiance with elderly Honda's. Most weren't born when those bikes > > > >> were new. > > > > >> > > --- On Thu, 5/14/09, [email protected] < > > > >> [email protected]> wrote: > > > > >> > > From: [email protected] <[email protected]> > > > >> > > Subject: [Nighthawk Lovers] Howresponsiveis a 1983 750sc NH? > > > >> > > To: "Nighthawk Motorcycle Lovers!" <<[email protected]> > > > >> [email protected]> > > > >> > > Date: Thursday, May 14, 2009, 8:35 AM > > > > >> > > Long story short... I bought my NH about 2 months ago from a guy who > > > >> > > didn't winterize it. It was such a deal for here in Alberta I bought > > > >> > > it. I cleaned the carbs and had them professionally tuned. I recharged > > > >> > > th K&N and replaced the plugs. When I got it up a running and took it > > > >> > > for a test drive it seemed to lack umph after everything was done.... > > > >> > > Since I didn't have it to ride before I bought it. I have nothing to > > > >> > > compare it to, but my 1982 CX500 which was superresponsiveand quick > > > >> > > off the line. My NH seems to just want to smoothly increase no matter > > > >> > > how much I roll on the throttle. Any thoughts on how to improve > > > >> > > throttle response time? Any help would be greatly appreciated, thanks > > > > >> > > Joel- Hide quoted text - > > > > >> > - Show quoted text -- Hide quoted text - > > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. 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