rehellek32 Posted June 6, 2011 Share Posted June 6, 2011 I have had a rough idle for a few years and after throwing parts and money at her i finally did a compression test which resulted in the following: #1 Cylinder 130psi low! #2 Cylinder 135psi low! #3 Cylinder 130psi low! #4 Cylinder 80psi VERY LOW!!! After getting these results I hooked up a compressor to the compession tester adapter, put the #4 cylinder at TDC and let in about 80psi and got a decent flow of air thru the oil filler hole... Tested the cylinders that had the higher reading and heard nothing but a tiny bit of liquidy his thru the intake valves. I have already started the tear down and am planning on valves and rings, maybe pistons. Question for any experienced mechanics/motorheads is what would overheating a few time cause only one cylinder to be lower than all the others? I also came across a fried cable from the stator to R/R which i must have bean riding with for years and never knew, could this have anything to do with the compression? Any help appreciated. Quote Link to comment Share on other sites More sharing options...
ironmike Posted June 6, 2011 Share Posted June 6, 2011 Off the top of my head, I'm thinking a broken ring & scored cylinder wall... pretty unlikely your electrical problem caused it. But I'm sure you're gonna find out. Good Luck! Quote Link to comment Share on other sites More sharing options...
rehellek32 Posted June 6, 2011 Author Share Posted June 6, 2011 Off the top of my head, I'm thinking a broken ring & scored cylinder wall... pretty unlikely your electrical problem caused it. But I'm sure you're gonna find out. Good Luck! That's what i was thinking but thought i'd ask anyway, thanks for the input... Now i just have to get hold of the special tool to drop the engine out the frame, Anyone know if this tool(s) is only avail from Honda? Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 6, 2011 Share Posted June 6, 2011 Off the top of my head, I'm thinking a broken ring & scored cylinder wall... pretty unlikely your electrical problem caused it. But I'm sure you're gonna find out. Good Luck! That's what i was thinking but thought i'd ask anyway, thanks for the input... Now i just have to get hold of the special tool to drop the engine out the frame, Anyone know if this tool(s) is only avail from Honda? Don't know how many miles are on the bike but after overheating, a blown headgasket could cause the low readings on the one hole. The electrical issues won't have anything to do with it. Quote Link to comment Share on other sites More sharing options...
rehellek32 Posted June 6, 2011 Author Share Posted June 6, 2011 Off the top of my head, I'm thinking a broken ring & scored cylinder wall... pretty unlikely your electrical problem caused it. But I'm sure you're gonna find out. Good Luck! That's what i was thinking but thought i'd ask anyway, thanks for the input... Now i just have to get hold of the special tool to drop the engine out the frame, Anyone know if this tool(s) is only avail from Honda? Don't know how many miles are on the bike but after overheating, a blown headgasket could cause the low readings on the one hole. The electrical issues won't have anything to do with it. It's a 99 with 20k and I've owned it since new. Meticulous about repairs, oil changes, fluids etc... First overheat was at about 500mi on a hot day in traffic with a tail wind. I would have put more miles on her if it hadn't run so rough but I would loose the itch... Anything I should look for or know of during the rebuild aside of what the Honda repair manual says? Quote Link to comment Share on other sites More sharing options...
HANKSXXX Posted June 6, 2011 Share Posted June 6, 2011 Check the cylinder bores for roundness. I'd suggest a digital bore gauge. Hank Quote Link to comment Share on other sites More sharing options...
EVLXX Posted June 6, 2011 Share Posted June 6, 2011 It could be a simple as a stuck ring... When you say overheating... by how much... I had the unfortunate experience of losing a gasket on a GS650 years ago, which resulted in a loss of all the oil over about 5 miles, at which point it over heated, seized, and Died. I let it cool for an hour pluged the hole, dropped in some new oil, rocked the engine a few times in gear, started it and rode it home. But I'm guessing your overheating was not that bad.... Quote Link to comment Share on other sites More sharing options...
TuffguyF4i Posted June 6, 2011 Share Posted June 6, 2011 Is that an after market case cover? Aren't they dark green? This has got to be a purely mechanical problem. Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 6, 2011 Share Posted June 6, 2011 Off the top of my head, I'm thinking a broken ring & scored cylinder wall... pretty unlikely your electrical problem caused it. But I'm sure you're gonna find out. Good Luck! That's what i was thinking but thought i'd ask anyway, thanks for the input... Now i just have to get hold of the special tool to drop the engine out the frame, Anyone know if this tool(s) is only avail from Honda? The only "special tool" I know of (except for Byrdman) , is the crown-type socket that is needed to adjust the engine mounting bolts. You can easily make this by modifying a standard socket of the correct size with a die-grinder. I'm at work right now, so I can't tell you what size I used. I'll look when I get home. Quote Link to comment Share on other sites More sharing options...
partsman Posted June 6, 2011 Share Posted June 6, 2011 Not too sure what can happen to valve seats/valves from a couple hot moments,but I'd be checking the head for warpage when its off.20k is nothing normally.No loss of coolant? Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 7, 2011 Share Posted June 7, 2011 In all and without knowing the whole story I can only go on general information. Based on the original scenario and readings I would have run the individual pistons to TDC or BDC and then attached an air hose to them one at a time to determine where the loss was. Rings, out the pan; intake valve out the throttle body; exhaust out the tailpipes and if the head gasket is blown you will generally see bubbles in the radiator fill port. Either way you know where the leak is. The XX engines are known for long life so I would be really surprized if you found a problem in the short block but I would check the deck and head to be sure the overtemp didn't warp either. Quote Link to comment Share on other sites More sharing options...
rehellek32 Posted June 8, 2011 Author Share Posted June 8, 2011 In all and without knowing the whole story I can only go on general information. Based on the original scenario and readings I would have run the individual pistons to TDC or BDC and then attached an air hose to them one at a time to determine where the loss was. Rings, out the pan; intake valve out the throttle body; exhaust out the tailpipes and if the head gasket is blown you will generally see bubbles in the radiator fill port. Either way you know where the leak is. The XX engines are known for long life so I would be really surprized if you found a problem in the short block but I would check the deck and head to be sure the overtemp didn't warp either. Thanks for all your feedback. Heres the photos of the pistons and heads... The #4 piston can slightly rotate by hand in the cylinder which makes me think piston pin and rings? Im thinking this is why I heard air through the oil filler hole (oil pan). I am trying to get my hands on a micrometer set to check clearances. The gasket seems almost new in person. Tomorrow im gonna make the custom socket to remove the adjuster nut to remove the engine all the way out so i can start inspecting rings etc and will take photos... Any other comments welcome, this is my first complete teardown so thanks for the help. The alt cover is original btw, I just stripped the paint and polished it a while back after i scraped it. Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 8, 2011 Share Posted June 8, 2011 Judging from the amount of carbon on the head, I'm guessing you don't make many trips to the red-line. Engines are like people, they need to exercise and eat right to stay healthy. What oil are you using? BTW, when you order a new head gasket, get the thin one (.018") from Cometic. It will bump the compression a little and you can still use 87 octane. Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 9, 2011 Share Posted June 9, 2011 Judging from the amount of carbon on the head, I'm guessing you don't make many trips to the red-line. Engines are like people, they need to exercise and eat right to stay healthy. What oil are you using? BTW, when you order a new head gasket, get the thin one (.018") from Cometic. It will bump the compression a little and you can still use 87 octane. Why would you run regular unleaded gas when the Owner's manual & EPA sticker recommend 91 RON min? Trips to the red-line are unnecessary as that engine has long since stopped making horsepower or torque. I do however agree engines like to be exercised. Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 9, 2011 Share Posted June 9, 2011 Judging from the amount of carbon on the head, I'm guessing you don't make many trips to the red-line. Engines are like people, they need to exercise and eat right to stay healthy. What oil are you using? BTW, when you order a new head gasket, get the thin one (.018") from Cometic. It will bump the compression a little and you can still use 87 octane. Why would you run regular unleaded gas when the Owner's manual & EPA sticker recommend 91 RON min? Trips to the red-line are unnecessary as that engine has long since stopped making horsepower or torque. I do however agree engines like to be exercised. Don't know about your owner's manual, but mine says to use minimum octane rating of 86. Regular unleaded is all I have ever used in my street-legal Bird. Got over 43K on the odo and it still runs like new. Had it on a dyno couple of years ago and it made 138HP with 4 into 1 Yosh and no P/C. Motor has never been apart. Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 9, 2011 Share Posted June 9, 2011 Judging from the amount of carbon on the head, I'm guessing you don't make many trips to the red-line. Engines are like people, they need to exercise and eat right to stay healthy. What oil are you using? BTW, when you order a new head gasket, get the thin one (.018") from Cometic. It will bump the compression a little and you can still use 87 octane. Why would you run regular unleaded gas when the Owner's manual & EPA sticker recommend 91 RON min? Trips to the red-line are unnecessary as that engine has long since stopped making horsepower or torque. I do however agree engines like to be exercised. Don't know about your owner's manual, but mine says to use minimum octane rating of 86. Regular unleaded is all I have ever used in my street-legal Bird. Got over 43K on the odo and it still runs like new. Had it on a dyno couple of years ago and it made 138HP with 4 into 1 Yosh and no P/C. Motor has never been apart. Interesting, the 02 and 03 want 91. Quote Link to comment Share on other sites More sharing options...
RC Randy Posted June 10, 2011 Share Posted June 10, 2011 My 99 and 03 both have the same fuel requirement according to the stickers on the frame. Always run 87 octane regular unleaded, which is the equivalent to 91RON rating. Quote Link to comment Share on other sites More sharing options...
The Krypt Keeper Posted June 10, 2011 Share Posted June 10, 2011 Yep run 87 in my bike '02 and loves it. If I have to run 91 or higher my XX don't like it, and will become buzzy in the pegs and bars. Throw in some lucas or seafoam every now in then and ride. Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 10, 2011 Share Posted June 10, 2011 Yep run 87 in my bike '02 and loves it. If I have to run 91 or higher my XX don't like it, and will become buzzy in the pegs and bars. I've never even tried 87. I run 93 and have since the bike was new. I mean the thing said 91 so the closest we have is 93. The plugs I just swaped out were honeycomb in color and I probably could have run them much longer. The engine runs electric smooth and no buzzing at all. I can ride that thing for mile after mile in comfort. Quote Link to comment Share on other sites More sharing options...
jon haney Posted June 10, 2011 Share Posted June 10, 2011 Yep run 87 in my bike '02 and loves it. If I have to run 91 or higher my XX don't like it, and will become buzzy in the pegs and bars. I've never even tried 87. I run 93 and have since the bike was new. I mean the thing said 91 so the closest we have is 93. The plugs I just swaped out were honeycomb in color and I probably could have run them much longer. The engine runs electric smooth and no buzzing at all. I can ride that thing for mile after mile in comfort. Running the higher octane won't hurt anything........except your wallet. :icon_doh: Quote Link to comment Share on other sites More sharing options...
kiwimack Posted June 10, 2011 Share Posted June 10, 2011 Yep run 87 in my bike '02 and loves it. If I have to run 91 or higher my XX don't like it, and will become buzzy in the pegs and bars. I've never even tried 87. I run 93 and have since the bike was new. I mean the thing said 91 so the closest we have is 93. The plugs I just swaped out were honeycomb in color and I probably could have run them much longer. The engine runs electric smooth and no buzzing at all. I can ride that thing for mile after mile in comfort. Running the higher octane won't hurt anything........except your wallet. :icon_doh: Mine don't like anything but 87 runs like shit on 91 2 cents Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 10, 2011 Share Posted June 10, 2011 Yep run 87 in my bike '02 and loves it. If I have to run 91 or higher my XX don't like it, and will become buzzy in the pegs and bars. I've never even tried 87. I run 93 and have since the bike was new. I mean the thing said 91 so the closest we have is 93. The plugs I just swaped out were honeycomb in color and I probably could have run them much longer. The engine runs electric smooth and no buzzing at all. I can ride that thing for mile after mile in comfort. Running the higher octane won't hurt anything........except your wallet. :icon_doh: At a difference of 1 dollar a tank full I don't see that being an issue...LOL Quote Link to comment Share on other sites More sharing options...
RodeRash Posted June 10, 2011 Share Posted June 10, 2011 If running Premium makes you feel good. Do it. It's your money. Quote Link to comment Share on other sites More sharing options...
OMG Posted June 10, 2011 Share Posted June 10, 2011 Somewhat off topic but about gas. One thing I have not understood is the price difference between grades. When I started driving gas was 17.9 cents for regular, ten cents more for mid grade and another ten cents for premium. With gas now at 3-4 dollars it's the same ten cents more each grade. Anyone know why? I know, older than dirt. Quote Link to comment Share on other sites More sharing options...
Sleeper Posted June 10, 2011 Share Posted June 10, 2011 If running Premium makes you feel good. Do it. It's your money. A few years back there was a test done in one of the magazines that took 3 high performance cars like the Corvette, Mustang GT and I can't remember the 3rd, which were supposed to run premium and drained it all out. They put enough regular gas in them to run each car 3 times down the quarter mile. Then they drained the gas again and put enough premium in for the same test runs. Interestingly the cars did run better times with the premium fuel. Now, you can run dirty fuel in a blackbird and no doubt it will run fine with it knock sensor there to adjust but for someone to say their bike runs like crap on premium while causing it to vibrate and such is just crazy. The sticker said 91 and I run 93. In 24,000 beautiful miles that bike has been flawless. In fact, I changed the plugs and to be frank didn't even need to because they looked that good. For the pennies it costs in difference and knowing how good things worked with slower burning fuel I'll stick with the good stuff. Quote Link to comment Share on other sites More sharing options...
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