Hi Matt, Sorry to hear about your trouble. I have feared doing that too, and double check it when I change the oil. I caught that mistake one time. A garage professional that dad went to did that, and they had to buy him a new motor.
I was a toolmaker in my first career. My father had a tool shop. I can tell you that boring a cylinder is not to difficult for set up time, if they have the equiptment, but the cam shaft seats, if they are horizontal, (I didn't look at your pic yet) but the camshaft boring is much more difficult. You will have to scout around and compare shops. Each shop has a different rate, and expertise. Small shops will typically have lower overhead and prices. Maybe even a shop that specializes in bike engines. My thought on it is it would be better to find a different engine and if necessary rebuilt it. You will find tool work is not cheap, and has to be very precise to fit bearing. ron _____ From: [email protected] [mailto:[email protected]] On Behalf Of Matthew Webb Sent: Friday, April 20, 2012 9:45 PM To: [email protected] Subject: [Nighthawk Lovers] rookie looking for suggestions 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 <https://plus.google.com/photos/118089145265544102347/albums/573367372099283 1665?authkey=CKH1v53yteGPnAE> 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 <http://www.ebay.com/itm/CYLINDER-HEAD-CB750-NIGHTHAWK-91-93-92-1991-1992-19 93-VALVE-TOP-END-ENGINE-MOTOR-/140691166315?pt=Motorcycles_Parts_Accessories &vxp=mtr&hash=item20c1d8d46b> head, another <http://www.ebay.com/itm/Honda-CB750-SC-Nighthawk-Good-Used-Original-Engine- Cylinder-Head-1992-BDK-/150711279313?pt=Motorcycles_Parts_Accessories&vxp=mt r&hash=item2317179ed1> cylinder head, camshafts. <http://www.ebay.com/itm/Honda-CB750-SC-Nighthawk-Good-Used-Original-Engine- Cam-Camshaft-Pair-1992-BDK-/400261036787?pt=Motorcycles_Parts_Accessories&vx p=mtr&hash=item5d316abaf3> 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 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.
