Begging to differ with you, the VW air cooled engine is the epitome of simplicity. The OHC 750 is a "bit" more difficult. You may not have too much trouble if it's only the top end, but it's definitely a complex system. If the compression overall is 120 or over, it's probably in the top end and disappearing oil is likely from valve stem seals and you have a leaking valve or two in #3. 'If compression is low overall - less than 100 or just 100 and evenly distributed, you also have a ring problem. I would say rebuild. I used to rebuild VW engines to put myself through school. Even in their simplicity there are complexities to deal with, because they are a pushrod engine with only OHVs, not OHCs, which would eliminate the need for tubes in which the pushrods activate the valves from an internal engine camshaft. If the compression is less than 120, then I would consider doing a complete rebuild on account of the bottom end (rings) being weak. Making a fresh and tight valve seal would likely further weaken the rings seals, especially if it was only tenderly cared for with relation to appearance.
________________________________ From: Allen Thomas <[email protected]> To: Nightwawk Lovers <[email protected]> Sent: Friday, March 2, 2012 6:10 AM Subject: Re: [Nighthawk Lovers] Nighthawk with disappearing oil My suggestion is to get a leak down tester and read up on how to use one. That will tell you exactly what is wrong without disassembly or $300. While I haven't torn down a bike engine it doesn't look bad at all to rebuild the top end, about as difficult as doing an air cooled VW bug. Sent via BlackBerry by AT&T ________________________________ From: Stefano Ascari <[email protected]> Sender: [email protected] Date: Thu, 1 Mar 2012 17:00:21 -0600 To: nighthawk_lovers<[email protected]> ReplyTo: [email protected] Subject: [Nighthawk Lovers] Nighthawk with disappearing oil Hi Everyone, So went in and spoke to the mechanic in person. It seems the pressure on cylinder #3 is 70 pounds (should be in the 140 range according to mechanic). He said for 300$ he could tear it apart and then he would be able to determine more exactly what was the cause. The motorcycle is in pristine condition overall. Both the front and rear tires are brand new and everything else has been well taken care of. At this point I think I'm looking at two options: A. Have the mechanic tear it apart and determine the problem with cyl #3 and then re-build it myself over the summer (I don't know anything about mechanics or how motorcycles operate). B. Sell the bike for parts. I have a working space in my garage and I'm ok learning new things. But like I've said, I have no previous experience with this kind of stuff. Is re-assembling an engine terribly complex? You guys have been extremely helpful in the past and I find this email list an invaluable asset. Thank you for all the informative emails!! Any suggestions? Stefano -- 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. -- 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.
