Thanks for the reassurance, The blue smoke at startup only lasts 10-15 secs and then runs clean until the next cold startup. I check the oil often but hardly ever add. I agree about changing the oil often. The oil in it when I got it was pretty gamey so I,m not sure of its past It had 23K when I bought it for $300. It needed a lot more than an oil change but it seems good now. Thanks again On 11/3/08, Dennis Hammerl <[EMAIL PROTECTED]> wrote: > > Not at all, one of my co-workers has one with over 36K and it runs fine. > I don't pay much attention to cold motors behavior since that's only a > temporary situation. The determining factor is always how much care it had > on the way to it's present state. Almost any motor will puff a bit cold. > Just lay a light on the floor so that the exhaust is between you and it. > Does it use any oil ? Do you have to add often ? Frequent oil changes will > prolong a motor's life for years. Lot's of early Wings smoked like mad on > start-up and they still run fine at over 100K. > > --- On *Mon, 11/3/08, [EMAIL PROTECTED] <[EMAIL PROTECTED]>* wrote: > > From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> > Subject: [Nighthawk Lovers] Re: Compression Testing > To: [email protected] > Date: Monday, November 3, 2008, 6:01 AM > > You mention that 23K is high but not excessive and I have been wondering > what that figure might for other nighthawk models. My 84 650 has about 26K > (Ihave had it only one season) is beginning to show a little blue smoke at > startup after sitting all day but over runs very well. Is the end near? > Thanks > > On 11/2/08, Dennis Hammerl <[EMAIL PROTECTED]> wrote: >> >> Your intentions are good but your methods need a little refining. >> Testing on a warm motor is preferred. Your measurements are all quite low >> and that tells me some about your situation. First off, both plugs out to >> reduce effort of starter. Check and adjust valve clearance before checking >> compression. 23K is considered high mileage for one of those but not >> excessive. When taking a compression reading, open the throttle completely >> and have the choke open as well. (if you can't get air into the engine, >> there is nothing to compress.) This alone should result in a higher reading. >> I would be quite happy with about 150lbs each. A Honda engine will run OK at >> as low as 100lbs. Below that figure, expect poor running. The difference >> between cylinders is important. That should be no more than 10~20lbs. >> FYI: compression tests are cumulative (longer you crank, the higher it >> gets up to a point) They are considered to be a rough indication of >> condition. A leak-down test tells far more and diagnoses problems. Operate >> the starter for no more than 5 seconds. That's more than enough to get >> results. >> Your running problems are indicative of carb problems more than engine. >> You didn't say what year 450 you have, earlier ones (80's) have drivability >> issues from lean carburation. >> Happy wrenching >> >> --- On *Sun, 11/2/08, Redtail <[EMAIL PROTECTED]>* wrote: >> >> From: Redtail <[EMAIL PROTECTED]> >> Subject: [Nighthawk Lovers] Compression Testing >> To: "Nighthawk Motorcycle Lovers!" <[email protected]> >> Date: Sunday, November 2, 2008, 4:23 PM >> >> I bought my first bike, a used CB450SC back in the summer and have >> been riding it ever since. It has 23000 miles on >> it. The engine >> coughs and spits and backfires sometimes, but starts and runs every >> time. I had a quick look at the carbs and gave them a quick clean at >> the time but plan on going at them again as soon as I quit riding for >> >> the winter, (which will be soon.) I borrowed a compression tester >> from a friend to check it out in case I have to perform a little >> engine work. I'm not necessarily good at diagnosing a problem, but >> once I know what is wrong, I can fix just about anything. >> >> >> A couple of questions: >> 1) Should the test be performed with the engine cold, warm or both? >> 2) What should a normal reading be? >> 3) Should both spark plugs be out at the time or does it matter? >> >> So far I have only checked it with a cold engine. The >> left cylinder >> >> tested about 80 to 85 each time, whereas the right one was down about >> 55 at first, but increased to 100 after checking it the forth time. >> (I used a spare boat battery >> so as not to wear down the bike battery >> and I let the starter cool for 10 minutes in between tests.) >> >> My thinking is that the oil was being circulated and coating the >> cylinder walls and increasing the pressure in the right cylinder, but >> >> what about the left one? Is there a problem with the rings in that >> one? >> >> Also, I read somewhere once that if one cylinder is low and you squirt >> some oil into it and then check the compression again, if the numbers >> >> increase the rings are worn, and if they stay the same, the valves are >> leaking. Is my thinking correct? >> >> Any help would be greatly appreciated. >> >> Paul B. >> >> >> >> >> >> >> >> >> > > > > > > > > >
--~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
