PT:1 1984 Honda CB700SC Nighthawk Issues

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Күн бұрын

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@jeffreybodine2897 3 ай бұрын

I have a nighthawk project bike that I went thru , first off , it doesnst sound like its hitting on all cylinders , I had a problem with the one plastic spark plug cap and it would smoke just like that and i too thought is was a internal engine problem at first , that thing is so smooth even running on three cylinders that it will fool you into thinkin its running on all 4 but its not ... replaced all 4 caps and its fine , no more smoke . Just start it up and touch the pipes without burning yourself to see if its hitting on all 4 . The carbs sound out of sync and clogged up and they gotta be right , re clean all the carbs and replace all the rubber gasket and orings , bench sync the carbs and make sure the intake rubbers are not leaking , a little carb spray around the intakes while its running will tell you if its leaking there . make sure you heat them up with a heat gun to remove /install the carbs , they are super rigid and this helps soften them up . Another note , all these older bikes run like crap with modern gas and honda leaned them out real good so they will not run right on stock jetting anymore . You have to up the pilot jet 3 sizes and put a washer under the needle on the carb slide on all cylinders to get you in the ballpark to fine tune it ... All the older hondas are like this , my 86 goldwing ... same thing . they wont run right with modern gas . Symptoms are hesitation from lower rpms , running on partial choke till they are completely warmed up to idle right , crappy low end response , stumbling ... Hope this helps

@thedragon2299 3 ай бұрын

@@jeffreybodine2897 kzbin.info/www/bejne/nYW9hqR-qJaAetEfeature=shared

@thedragon2299 3 ай бұрын

@jeffreybodine2897 the bike had just left another shop where the customer spent over $3,000 having new topend and carbs rebuilt. I tore it down and found bad workmanship. They left alot of carbon on the valves and some carbon broke off and was stuck in the valve seat, not allowing the valve to close. More on this bike soon, because when I found the problems, customer didn't want to spend anymore money on it and he picked it up in peices. Now that he has time to think about it he wants to bring it back and have me rebuild it right. Thanks for watching 🐲 and commenting. I do this everyday, seen it all. Check out my channel and Facebook too Dragon Worx: facebook.com/profile.php?id=100057489818717&mibextid=ZbWKwL

@ConsortiumBlaster 2 ай бұрын

Sounds like the carbs are out of sync. I Have an 86 that i bought new. Still have it. At one point i kept it in the house for 2-3 years no fuel. When i decided to run it again it was rough and needed choke. It was the diaphragms that stiffened, which at the time i didn't know. After about 2 years of running it very little, the diaphragms loosened up and ran fine. To Sync these carbs you need a vacuum gauge setup that gauges all 4 carbs, 1 is your base which you adjust the others to. The engine will sound like this one when 1 or more carbs are out of sync with others making it run on the richer carbs and the other carbs lagging, which makes it smoke because the choke is choking the rich carbs and the lean carbs. This is what it sounds like to me. I hope this helps.

@thedragon2299 2 ай бұрын

@ConsortiumBlaster hey thanks appreciate the help. You have learned a couple things over the years I see. I actually own a Vintage Motorcycles Restoration shop, I'm doing this stuff everyday and I do infact have several sync gauges, however this was alittle more than out if sync, this customer had just got screwed bad at another shop for $3500. The motor and carbs were supposedly rebuilt, but what I found would say otherwise, oh they did some work alright but it was bad workmanship. In this video, one cylinder didn't even have any compression and the carbs were actually overflowing. You will see the conclusion, or at least more on this bike coming soon. After I tore the engine down and found the shotty work, the customer decided not to put another $3500 dollars into it, and picked up the bike, after a week of thinking, he called me back and set up an appointment to bring it back for a proper rebuild. It should be here in a couple weeks or less. So check back for those videos coming soon. Thanks for watching and commenting 🐲!

@thedragon2299 2 ай бұрын

Here is part2 you might have missed kzbin.info/www/bejne/nYW9hqR-qJaAetEfeature=shared

@ConsortiumBlaster 2 ай бұрын

@@thedragon2299 KISS :)

@andrewfarrant198 4 ай бұрын

I have the exact same bike, taking those carbs off are a pain in the ass because the boots are really stiff, & not alot of room.

@doctorseuss5349 4 ай бұрын

Agreed, but ever tried a V4?

@andrewfarrant198 4 ай бұрын

Thankfully no!

@GoldbergPatriot 4 ай бұрын

Sometimes I can push them inside the box, get everything in place then pull them out to slide in place. I’ve never worked on one of these though

@thedragon2299 4 ай бұрын

I totally agree, I've done several carb jobs on these bikes and the boots are a big pain in the ass. I usually warm them up first and it makes it slightly easier. Thanks for watching 🐲

@thedragon2299 4 ай бұрын

@@doctorseuss5349 so true, I have a VF500F in the shop right now that I'm about to do carbs on🙃

@doctorseuss5349 4 ай бұрын

Loose intake manifolds??

@thedragon2299 4 ай бұрын

Didn't seem like it, but I've only just begun checking it over, was trying to get a good video to show the customer what it was doing. It's definitely not running on all 4 cylinders.

@petev.9357 4 ай бұрын

Surprised you didn't check all 4 headers. Sounds like at least 3 things going on. Only running on 2 cylinders, cam timing might be wrong, and carbs NOT right.

@thedragon2299 4 ай бұрын

Yeah, I'm getting there, just starting on it. I mainly do the video so the customer can actually see what's going on with it. Can hear its definitely not running on all 4 cylinders. Was just alittle shocked because the customer said it was running much better than that, but sat since March.