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ryancoke
Joined: 09 Mar 2016 Posts: 7
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Posted: Wed Mar 09, 2016 5:16 pm Post subject: Top Dead Centre |
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| . This is my first horizontal engine. I have five motorcycles but they're all in line or V. I am trying to do a leak check on the cylinders. Can someone describe to me how to rotate the crankshaft find top dead center and where to access the crankshaft to rotate the engine . I can't seem to find the manual thank you very much take care |
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ryancoke
Joined: 09 Mar 2016 Posts: 7
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Posted: Wed Mar 09, 2016 7:20 pm Post subject: |
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| Nobody knows? |
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Flying Duck PsyKotic Waterfowl

Joined: 27 Jan 2005 Posts: 10102 Location: Bumf***, WA
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Posted: Wed Mar 09, 2016 8:43 pm Post subject: |
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On a K bike it's actually left dead center. (That's a joke.)
Easiest way to turn the engine is to put it on the center stand, put in in fifth and rock the back wheel.
Here's a link with the BMW shop manuals that will probably help you find TDC.
http://www.kbikeparts.com/classickbikes.com/ckb.tech/ckb.tech.toc.htm _________________ 93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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ryancoke
Joined: 09 Mar 2016 Posts: 7
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Posted: Wed Mar 09, 2016 10:57 pm Post subject: |
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| Lol duck. But the problem is I have the centre stand right off the bike. I suppose I could put some scissor jacks below it. Thx |
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Flying Duck PsyKotic Waterfowl

Joined: 27 Jan 2005 Posts: 10102 Location: Bumf***, WA
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Posted: Thu Mar 10, 2016 12:11 am Post subject: |
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The other option is to pull the stuff/battery under the rider and run a sawhorse through the frame to support it. Much more stable than jacking. _________________ 93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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Grunter Flying Brick Rider
Joined: 30 Sep 2015 Posts: 369 Location: North East England
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Posted: Thu Mar 10, 2016 6:00 pm Post subject: Top Dead centre. |
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I have an old spark plug which has the centre removed and then opened out to take a 5mm wide rod. If you have something similar, Insert the spark plug into No 1 cylinder there is no need to have it more than finger tight. If you don't, a slightly thicker rod or even a wooden dowel hand held, will do the same job
Then if you remove the valve cover you will find the camshaft has hexagonal castings on the area between the cam lobes. with the gearbox in in neutral, fit a 19mm open ended spanner on the hexagon and turn the engine anti-clockwise to rotate the crankshaft. (This is the way the motor runs)
Insert the 5mm rod into the converted spark plug until it touches the piston and as the engine brings the piston up to TDC, the rod will move out until it reaches the TDC point and then using finger pressure on the rod, it will follow the piston down. It may take a bit of trial and error to get exact TDC.
Make note that when you have reached what you judge to be TDC make sure both inlet and exhaust valves are closed, if they are not, rotate the crank one full revolution which then bring it to the correct TDC. _________________ 1997 K1100LT
1994 R1100RS
Last edited by Grunter on Tue Mar 15, 2016 3:10 pm; edited 1 time in total |
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ryancoke
Joined: 09 Mar 2016 Posts: 7
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Posted: Fri Mar 11, 2016 5:14 pm Post subject: |
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| OK guys, I raised the back and put it in high gear and there is no way I can spin the tire. What ahappened to the old way like on my Suzuki of hooking a socket up to the flywheel and turning the crank shaft that way. Does BMW not do the same? |
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Mike d Mad Brick Rider
Joined: 19 Feb 2010 Posts: 130 Location: Daventry UK
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Posted: Fri Mar 11, 2016 8:26 pm Post subject: |
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| Quote: | | What ahappened to the old way like on my Suzuki of hooking a socket up to the flywheel and turning the crank shaft that way. Does BMW not do the same? |
Well for one you can't get to the flywheel without removing the gearbox.
Mike |
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Flying Duck PsyKotic Waterfowl

Joined: 27 Jan 2005 Posts: 10102 Location: Bumf***, WA
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Posted: Fri Mar 11, 2016 10:51 pm Post subject: |
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| ryancoke wrote: | | OK guys, I raised the back and put it in high gear and there is no way I can spin the tire. What ahappened to the old way like on my Suzuki of hooking a socket up to the flywheel and turning the crank shaft that way. Does BMW not do the same? |
To get some better leverage you can pull the hub cap and use the tire iron on the center lug bolt. _________________ 93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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SugarHillCTD Site Admin

Joined: 10 Oct 2007 Posts: 4238 Location: Now in Eastern Pennsylvania
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Posted: Sat Mar 12, 2016 7:40 am Post subject: |
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| ryancoke wrote: | | OK guys, I raised the back and put it in high gear and there is no way I can spin the tire. What ahappened to the old way like on my Suzuki of hooking a socket up to the flywheel and turning the crank shaft that way. Does BMW not do the same? |
You are trying the rear wheel method WITH the sparkplugs removed, correct?
It will not smoothly turn the engine but it will "bump" it a bit at a time.
You move the rear wheel backwards slightly until it meets resistance then turn it in the normal direction with some force. You gain some force by using the slack in the drivetrain.
I do this to check valve clearance. _________________ John & Cathy
'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F. |
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ryancoke
Joined: 09 Mar 2016 Posts: 7
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Posted: Mon Mar 14, 2016 3:48 pm Post subject: |
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Ok I tried the rear wheel method, yes spark plugs are out (would be pretty tough with them in!), and still find this a pain in the butt and not very accurate. Are these really the only ways of getting TDC on this bike? I could have done all 5 of my other bikes by now! Lol
Using a breaker bar and socket on the wheel hub would require spinning the engine backwards. If you spin the engine forward it would just loosen the wheel nut. Not a fan of spinning engines backwards. |
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Grunter Flying Brick Rider
Joined: 30 Sep 2015 Posts: 369 Location: North East England
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Posted: Tue Mar 15, 2016 3:13 pm Post subject: TDC |
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I don't mean to upset anyone but possibly the only easy way to get TDC on a 'K' is the way I have described in my previous post. It works every time and will get VERY accurqte results. I have been doing this way since 1988!
Turning the rear wheel is a very crude way to do it and will only gt less than average accuracy, however many times you try. The hexagons cast on the camshaft are there for that specific purpose. _________________ 1997 K1100LT
1994 R1100RS |
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Flying Duck PsyKotic Waterfowl

Joined: 27 Jan 2005 Posts: 10102 Location: Bumf***, WA
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Posted: Wed Mar 16, 2016 1:00 am Post subject: Re: TDC |
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| Grunter wrote: | I don't mean to upset anyone but possibly the only easy way to get TDC on a 'K' is the way I have described in my previous post. It works every time and will get VERY accurqte results. I have been doing this way since 1988!
Turning the rear wheel is a very crude way to do it and will only gt less than average accuracy, however many times you try. The hexagons cast on the camshaft are there for that specific purpose. |
I've never found the need to find TDC but you make a good point here. Or you can use the bolts at the front of the cams - provided you're turning clockwise. _________________ 93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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Jnclem Big Brick Rider
Joined: 07 Jul 2015 Posts: 64 Location: Gunnison, CO.
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Posted: Wed Mar 23, 2016 5:51 pm Post subject: |
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I needed to find TDC to check my valves. I've always used the rear wheel method on all my BMWs, but next time I check them on the K, I'll use the cam shaft. Sounds good. I just never looked for another way to do it besides turning the rear wheel. _________________ '93 K1100LT, '89 R100GS |
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Flying Duck PsyKotic Waterfowl

Joined: 27 Jan 2005 Posts: 10102 Location: Bumf***, WA
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Posted: Wed Mar 23, 2016 8:37 pm Post subject: |
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You really don't need to find exact TDC to do valves. Just get the cam lobe pointing more or less straight out from the direction of valve travel as the rest of the cam lobe profile is circular. _________________ 93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE |
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