Did you put in new exhaust seals? Make sure they are tight. Date: Fri, 3 Aug 2012 17:02:22 -0300 Subject: Re: [Nighthawk Lovers] Re: rookie looking for suggestions From: [email protected] To: [email protected]
Just guessing (obviously) I'd say it's the top end not the bottom. A rod knock would only make half as many noises as a top end issue. Dave On 3 August 2012 16:24, Ross M. Jamison <[email protected]> wrote: Sounds like rod knock. Thank you, Ross M. Jamison Sent from my iPhone On Aug 3, 2012, at 1:13 PM, Matthew Webb <[email protected]> wrote: Here'a a much belated update: I started removing and dissasembling my engine (photos here) which turned out to be a pretty big challenge without having much experience. But it was tons of fun and I learned a lot while struggling and cursing in my blazing hot shed. While I was doing this a used engine with 22k miles popped up on eBay and just so happened to be located in my city so I scooped it up. By some miracle, I manage to succesfully install the new engine, put all the pieces together, and get the bike started! I think I remember hearing a slight noise from the engine but I was probably too estatic notice. I took the bike for a short test ride and at some point during the ride I noticed a tapping noise coming from the engine. So I'm not exactly sure when the noise started. Its possible the engine had been sitting for a while before I bought it. During the ride the bike seemed to perform 100% fine, aside from the noise. Back at home I took a video to capture the noise. I used a tube to listen to the engine and I think the noise is coming from the back of the lower crankcase. From the reading I've down it sounds like that type of noise means a valve needs to be adjusted? But the Clymer reads the valves adjust themselves automatically? So maybe a piston ring is off or something? Can anyone watch the video and help ID the noise? At this point I think my best bet is to take it to a shop and have pros look at it. Even if I have to shell out an arm and a leg I just want to be on the road again. http://youtu.be/PurYX89KWzc Thanks! - Matt On Friday, April 20, 2012 10:44:30 PM UTC-4, Matthew Webb wrote: Hi my name is Matt. I'm new to the group and I recently got my first bike, a 1992 CB750 with 3,800 miles for $1,800. It was always garage kept and in very good condition. I had had the bike for only about 2 months but had put almost 2,000 miles on it already. At the time I was getting home from work in the dark and the cold and kept putting off my first bike maintenance until a weekend when I could do some work in the daylight. I made a big rookie mistake and ran my bike dry and the engine locked up when I stopped at a traffic light. The low oil indicator light had turned on that morning but I was hurrying to a meeting and thought I would be able to make it before things got serious. I got my bike back to my house, and a few weeks later poured some oil over the top of the engine, manually turned the engine, and then was able to get it to start with no problem. However, the engine didn't seem to respond right. So I looked into the top more and found some pretty serious scouring on the exhaust camshafts, exhaust camshaft holders, and crankcase. It also looks like some of the rubber stuff on the defoaming chamber covers melted, but I'm not sure. The rest of the top end looked completely fine, even the intake camshaft. See pictures for details but be warned, they are depressing. I am worried that pieces of metal may have gotten into the bottom of the engine and wrecked more havoc. I'm also wondering if there may be more damage than I've seen from when my engine locked up. Does anyone know what damage is typical when you run your engine dry? Is it likely the entire engine will need to be replaced? I have searched past messages but have not found much. Possibly because I don't know what is best to search for. I've done a lot of other reading so far and have some ideas but wanted to run it by the group first. To me it looks like I have a few options: 1) Sell the bike as is on CL for parts to someone who knows what they are doing 2) Purchase replacement parts for the damaged components and replace them. With a quick search I have found these on ebay: cylinder head, another cylinder head, camshafts. I don't have much experience working with engines but I do have a Clymer manual. The camshafts and holders look easy to replace but the body of the crankcase is also damaged where the camshafts sit. Would it be possible to have a shop re-machine it so that I wouldn't need to replace it? 3) Take it to a shop, have them replace the parts and open the bottom of the engine to look for more damage. 4) Purchase another CB750 and use my first one as a parts bike. Also part out my first one on ebay since the rest of the bike is in excellent condition. Any suggestions would be appreciated, thanks. - Matt -- You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To view this discussion on the web visit https://groups.google.com/d/msg/nighthawk_lovers/-/3tYvbgQMpagJ. 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. -- 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. -- If you forward this e-mail please remove my address. -- 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. -- 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.
