fastbob Posted February 24, 2018 Share Posted February 24, 2018 (edited) I don't see the relationship between the torque on the head bolts and the compression readings , not on a static test anyway . Is the compression lower now than it was before you removed all that carbon ? Also did you do a dry test and a wet test ? If there is a marked improvement when you squirt a little oil down the plug holes its unfortunately not good news. Hope it all works out in the end. Edited February 24, 2018 by fastbob Quote Link to comment Share on other sites More sharing options...
fastbob Posted February 24, 2018 Share Posted February 24, 2018 How are you checking TDC?Im thinking valve timing too I really don't want to spoil anyone's evening but I'm thinking piston rings and bores especially now that the ridge of carbon has been removed from the top of the stroke . I do hope I'm wrong. Quote Link to comment Share on other sites More sharing options...
leener Posted February 24, 2018 Author Share Posted February 24, 2018 How are you checking TDC?Im thinking valve timing too Now I'm starting to worry. I set the crank to T1 (I think - need to see photos) at the marker, and 1 piston up, 2 down. Both arrows on the cams were facing each other.... Quote Link to comment Share on other sites More sharing options...
leener Posted February 24, 2018 Author Share Posted February 24, 2018 Cheers, Bob. Will try throwing liquid down tomorrow and see what happens. I did first test and hit around 50 on all three. Second test I squirted a little WD40 in each spark hole and got either 55 or 60. Tomorrow will give us a real chance to find out. I hoped that maybe the bolts were not tightened enough, thus causing air to escape. Already, the signs are bad. Quote Link to comment Share on other sites More sharing options...
Guest Posted February 24, 2018 Share Posted February 24, 2018 Don't forget that the rings have to bed-in. And you need to lube the bores thoroughly with engine oil when you re-assemble. Quote Link to comment Share on other sites More sharing options...
SlowBusa Posted February 24, 2018 Share Posted February 24, 2018 How are you checking TDC?Im thinking valve timing too Now I'm starting to worry. I set the crank to T1 (I think - need to see photos) at the marker, and 1 piston up, 2 down. Both arrows on the cams were facing each other.... Dont trust the TDC marker in the timing window use something like a straw down the plug hole and turn over till you know where the real TDC isI use on of these as a depth marker.....one tooth out will make a HUGE difference in PSI Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted February 24, 2018 Share Posted February 24, 2018 May have missed it in your posts but you have checked the valve clearances when the head was back on? Quote Link to comment Share on other sites More sharing options...
leener Posted February 24, 2018 Author Share Posted February 24, 2018 May have missed it in your posts but you have checked the valve clearances when the head was back on? Ah, shhheeeeiiiiahhhttt! I did not do that. I’ll get the head back off and do the checks and make sure I have it all right.The cams were spot on, going from memory. I had the pictures of where the arrows positio and the teeth were right, but I will check and check.This is so vital, because I want to make it so I can show others how they don’t need to scrap a bike, or get into debt for repairs. I have to finish this. I might end up keeping this bike. Quote Link to comment Share on other sites More sharing options...
SlowBusa Posted February 24, 2018 Share Posted February 24, 2018 Why are you taking the head back off?The head gasket is now compressed which "could" make it not seal as well the second time aroundEDIT: just re-read im guessing you mean cam cover? Quote Link to comment Share on other sites More sharing options...
fastbob Posted February 25, 2018 Share Posted February 25, 2018 Just for my own information, what is the process of carrying out a compression test ? The bit that's puzzling me is why you need to accurately measure TDC . I don't know but I would have thought that you simply attach a compression gauge , rotate the engine THROUGH TDC and read off the highest pressure that is indicated . Surely the highest reading will occur at TDC anyway . If you are going to determine TDC with a straw or depth gauge before attaching a compression gauge , how do you then create any pressure in the combustion chamber to measure ? Quote Link to comment Share on other sites More sharing options...
fastbob Posted February 25, 2018 Share Posted February 25, 2018 Don't forget that the rings have to bed-in. And you need to lube the bores thoroughly with engine oil when you re-assemble. There's no bedding in to do because the rings have not been touched , our friend has so far focused all his attention on the valves and guides. Quote Link to comment Share on other sites More sharing options...
SlowBusa Posted February 25, 2018 Share Posted February 25, 2018 Just for my own information, what is the process of carrying out a compression test ? The bit that's puzzling me is why you need to accurately measure TDC . I don't know but I would have thought that you simply attach a compression gauge , rotate the engine THROUGH TDC and read off the highest pressure that is indicated . Surely the highest reading will occur at TDC anyway . If you are going to determine TDC with a straw or depth gauge before attaching a compression gauge , how do you then create any pressure in the combustion chamber to measure ? Screw in the compression tester,make sure all other cylinders Dont have spark plugs in (so engine turns over at least 300rpm)Also turning the engine over by hand wont generate enough pressure to read properly so has to be done with starter motorIf the TDC isnt accurate then the valve timing Will be off, and that seriously affects PSI Quote Link to comment Share on other sites More sharing options...
TimR Posted February 25, 2018 Share Posted February 25, 2018 You're doing well there. Re bolts . Did you make sure the thread holes were clear of liquid etc ( oil /water) and debris . As liquid can cause a hydrolock on the threads and give a false reading on torque ( when the liquid compresses to its ultimate point it won't allow the bolt in further ) Did you have the pistons out ? If so in replacement did you mske sure the rings gaps were all in a different positions ? Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted February 25, 2018 Share Posted February 25, 2018 May have missed it in your posts but you have checked the valve clearances when the head was back on? Ah, shhheeeeiiiiahhhttt! I did not do that. I’ll get the head back off and do the checks and make sure I have it all right.The cams were spot on, going from memory. I had the pictures of where the arrows positio and the teeth were right, but I will check and check.This is so vital, because I want to make it so I can show others how they don’t need to scrap a bike, or get into debt for repairs. I have to finish this. I might end up keeping this bike.No need to remove the head to check the clearances,just the cam cover.Procedure should be in Haynes manual. Quote Link to comment Share on other sites More sharing options...
leener Posted February 25, 2018 Author Share Posted February 25, 2018 EDIT: just re-read im guessing you mean cam cover? Cam cover. I reached my mental and physical capacity by the end of yesterday.I might have to take it all off, but my plan for today is to do a quick wet compression test, and then strongly consider how I set the timing, when reconstructing the head. I need to get my last phone out and examine the photos I took of the crank position, and the cams. I did it from memory, so It's entirely possible that I failed to set it up exactly as it was. This is more likely, than anything else, I think. It is also possible that there is a problem with the piston rings, but one step at a time.No work has been done on the pistons, other than carefully removing surface carbon. It's difficult to get up and start the job until the caffeine has worked its way up to the brain. Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted February 25, 2018 Share Posted February 25, 2018 Just for my own information, what is the process of carrying out a compression test ? The bit that's puzzling me is why you need to accurately measure TDC . I don't know but I would have thought that you simply attach a compression gauge , rotate the engine THROUGH TDC and read off the highest pressure that is indicated . Surely the highest reading will occur at TDC anyway . If you are going to determine TDC with a straw or depth gauge before attaching a compression gauge , how do you then create any pressure in the combustion chamber to measure ? Screw in the compression tester,make sure all other cylinders Dont have spark plugs in (so engine turns over at least 300rpm)Also turning the engine over by hand wont generate enough pressure to read properly so has to be done with starter motorIf the TDC isnt accurate then the valve timing Will be off, and that seriously affects PSIThrottle should be wide open aswell.Don't have the spark plugs in the leads while cranking,fuel will still be drawn in and spat out the plug hole,any spark will ignite the fuel (seen it happen)Also crank the engine on the starter until the pressure gauge stops rising.Assume your battery is in good health and its cranking at the normal speed? Quote Link to comment Share on other sites More sharing options...
Bianco2564 Posted February 25, 2018 Share Posted February 25, 2018 A quick Google shows the triple is a bit prone to losing valve clearance due to seat and valve wear. Quote Link to comment Share on other sites More sharing options...
fastbob Posted February 25, 2018 Share Posted February 25, 2018 A quick Google shows the triple is a bit prone to losing valve clearance due to seat and valve wear. Especially if you have just ground in all the valves so it almost certainly needs re shimming now . Things might be looking up again . Quote Link to comment Share on other sites More sharing options...
fastbob Posted February 25, 2018 Share Posted February 25, 2018 It's difficult to get up and start the job until the caffeine has worked its way up to the brain.Crickey, how do you take your coffee then ? Quote Link to comment Share on other sites More sharing options...
megawatt Posted February 25, 2018 Share Posted February 25, 2018 Did you triple check that No. 1 cylinder was at TDC whilst cams were in correct position BEFORE you turned the crank??? Quote Link to comment Share on other sites More sharing options...
leener Posted February 25, 2018 Author Share Posted February 25, 2018 Outside freezing my nuts off.Crank at T1 and arrows... going to do liquid test This is how it was set before cams off and put back at T1. Now I’m not sure what to do, other than test the rings for leakage. Quote Link to comment Share on other sites More sharing options...
leener Posted February 25, 2018 Author Share Posted February 25, 2018 A quick Google shows the triple is a bit prone to losing valve clearance due to seat and valve wear. Especially if you have just ground in all the valves so it almost certainly needs re shimming now . Things might be looking up again . Where’s them feeler gauges...Oh, and six spoons of coffee, twenty sweeteners. Legs are aching from yesterday. The life of a desk job vs a mechanic. Quote Link to comment Share on other sites More sharing options...
leener Posted February 25, 2018 Author Share Posted February 25, 2018 These are the current valve clearances: And the Haynes manual: Quote Link to comment Share on other sites More sharing options...
megawatt Posted February 25, 2018 Share Posted February 25, 2018 Ring me? Quote Link to comment Share on other sites More sharing options...
leener Posted February 25, 2018 Author Share Posted February 25, 2018 Cheers, MW. In conclusion to our chat, I have a full understanding of what comes next. Pistons are coming out next week for inspection and repair.Wet compression was as follows:Accidentally added WAY too much oil (a real squirter) to cylinder 1: Dry cylinder 2: Wet cylinder 2: Dry cylinder 3: Wet cylinder 3: Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.