I am trying to figure out how to un-press the crankshaft (have a sacrificial crank to practice on). So if you have seen this done I can use whatever hints or instructions you can provide.
Also, anyone have the number on the bearings?
Thanks,
Richard
Re: Has anyone taken a crankshaft apart?
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tgm_enterprizes
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waugh.marshall
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Re: Has anyone taken a crankshaft apart?
Richard, It can be done with care. The fine splines obviously have to return exactly when refitting. What brings you to do this ? Marshall.
Re: Has anyone taken a crankshaft apart?
You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted.
Re: Has anyone taken a crankshaft apart?
Here is what I used to do... .. I would have crankshafts which had too much freeplay on the left connecting rod and another crank with too much freeplay on the right conn rod and have the bad sections pressed off and then the two good sections pressed back on to make one usable crank. It wasn't a rebuilt or a new crank, it was just a used crank which would work. I thought I might have some balance problems since I was not having the reassembled crank balanced (the shop doing my work did not perform this task) but I never noticed any problems. Maybe I was lucky. I was able to create 6 usable cranks this way which were all put into service. A place which does machine work for motorcycles would be able to help you.
If you are trying to rebuild a crank, you have several obstacles to overcome;
1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals. 2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm. 4) If you crank is showing any rust or pitting on the journals, that will need repair. 5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding. 6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now.
good luck, Dale
-----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart?
You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted. #ygrps-yiv-463681245
If you are trying to rebuild a crank, you have several obstacles to overcome;
1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals. 2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm. 4) If you crank is showing any rust or pitting on the journals, that will need repair. 5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding. 6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now.
good luck, Dale
-----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart?
You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted. #ygrps-yiv-463681245
Re: Has anyone taken a crankshaft apart?
What type of bearing is in the pressed rod assembly, needle or ball? Is it normal that they play side ways a bit? I noticed a few did, but up and down play is solid. Same with the wrist pin, a bit of wobble but up and down was solid.
Can you press a shim in the piston pin area to fix the play? Older Yamaha 2 strokes had a bronze bushing at the pin right? Or am I lost.
Sent from my iPhone
Here is what I used to do... .. I would have crankshafts which had too much freeplay on the left connecting rod and another crank with too much freeplay on the right conn rod and have the bad sections pressed off and then the two good sections pressed back on to make one usable crank. It wasn't a rebuilt or a new crank, it was just a used crank which would work. I thought I might have some balance problems since I was not having the reassembled crank balanced (the shop doing my work did not perform this task) but I never noticed any problems.. Maybe I was lucky. I was able to create 6 usable cranks this way which were all put into service. A place which does machine work for motorcycles would be able to help you.
If you are trying to rebuild a crank, you have several obstacles to overcome;
1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals. 2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm. 4) If you crank is showing any rust or pitting on the journals, that will need repair. 5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding. 6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now.
good luck, Dale
-----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart?
You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted.
Can you press a shim in the piston pin area to fix the play? Older Yamaha 2 strokes had a bronze bushing at the pin right? Or am I lost.
Sent from my iPhone
On May 14, 2019, at 12:07 PM, goinhm@... [2cylinderhondas] wrote:
Here is what I used to do... .. I would have crankshafts which had too much freeplay on the left connecting rod and another crank with too much freeplay on the right conn rod and have the bad sections pressed off and then the two good sections pressed back on to make one usable crank. It wasn't a rebuilt or a new crank, it was just a used crank which would work. I thought I might have some balance problems since I was not having the reassembled crank balanced (the shop doing my work did not perform this task) but I never noticed any problems.. Maybe I was lucky. I was able to create 6 usable cranks this way which were all put into service. A place which does machine work for motorcycles would be able to help you.
If you are trying to rebuild a crank, you have several obstacles to overcome;
1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals. 2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm. 4) If you crank is showing any rust or pitting on the journals, that will need repair. 5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding. 6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now.
good luck, Dale
-----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart?
You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted.
-
waugh.marshall
- Posts: 1
- Joined: Fri May 10, 2019 3:24 am
Re: Has anyone taken a crankshaft apart?
I have posted a couple of opened crank photos from ten years ago. They show how fine the splines are .... Spline sizes do vary from one assembly to another.
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waugh.marshall
- Posts: 1
- Joined: Fri May 10, 2019 3:24 am
Re: Has anyone taken a crankshaft apart?
The N600 engine was produced with two different sizes of big end needle bearing .... Just to make things more confusing. Lol.
Re: Has anyone taken a crankshaft apart?
Attachments :But Dale; The inner bearings are normally shot too as that is where the oil flow starts for the crank shaft. I too used a motor cycle machine shop to pull the crank shaft apart and after going through 8 assemblies only one had usable cages and the rollers weren t all out of shape. (the rollers were stuck in one spot causing flat areas). And, Honda used 10 different sizes of bearing rollers. The journals were tore up along with the rods, but yes they would go back together and run, but no assurances for how long. Bill From: 2cylinderhondas@yahoogroups.com [mailto:2cylinderhondas@yahoogroups.com]
Sent: Tuesday, May 14, 2019 12:07 PM
To: 2cylinderhondas@yahoogroups.com
Subject: Re: [2cylinderhondas] Re: Has anyone taken a crankshaft apart? Here is what I used to do... .. I would have crankshafts which had too much freeplay on the left connecting rod and another crank with too much freeplay on the right conn rod and have the bad sections pressed off and then the two good sections pressed back on to make one usable crank. It wasn't a rebuilt or a new crank, it was just a used crank which would work. I thought I might have some balance problems since I was not having the reassembled crank balanced (the shop doing my work did not perform this task) but I never noticed any problems.. Maybe I was lucky. I was able to create 6 usable cranks this way which were all put into service.A place which does machine work for motorcycles would be able to help you. If you are trying to rebuild a crank, you have several obstacles to overcome; 1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals.2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm.4) If you crank is showing any rust or pitting on the journals, that will need repair.5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding.6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now. good luck,Dale -----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart? You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted.
Sent: Tuesday, May 14, 2019 12:07 PM
To: 2cylinderhondas@yahoogroups.com
Subject: Re: [2cylinderhondas] Re: Has anyone taken a crankshaft apart? Here is what I used to do... .. I would have crankshafts which had too much freeplay on the left connecting rod and another crank with too much freeplay on the right conn rod and have the bad sections pressed off and then the two good sections pressed back on to make one usable crank. It wasn't a rebuilt or a new crank, it was just a used crank which would work. I thought I might have some balance problems since I was not having the reassembled crank balanced (the shop doing my work did not perform this task) but I never noticed any problems.. Maybe I was lucky. I was able to create 6 usable cranks this way which were all put into service.A place which does machine work for motorcycles would be able to help you. If you are trying to rebuild a crank, you have several obstacles to overcome; 1) there are not rebuild kits for these cranks. You are going to need to locate the needle bearings and seals.2) Honda used to sell oversize piston pins for the top end of the connecting rod..... these are no longer made. You are going to need to bring back both ends of the connecting rods to the correct diameter. 3) Where the connecting rod connects to the crankpin, you have an aluminum cage and needle bearings. If you used oversize bearings, you would need to make a special cage to accommodate the bearings. If you go with stock size, you need to verify the cage doesn't have excessive wear. I have heard people suggest replacing the bearings with a sleeve bearing (like most passenger cars) but that might only be good if you are using the car for show since the oil system for these cars was designed for needle bearings. Do you need a cage? I noticed on older Evinrude outboard boats motors, they use needle bearings at the crank and piston end of the conn rod and do not use a cage... the bearings float. And that is on a 115 hp engine (4 cylinders, 2 stroke) running at 5000 rpm.4) If you crank is showing any rust or pitting on the journals, that will need repair.5) you also have the two bearing assemblies on each end which need to be checked and may need rebuilding.6) When you press apart the crank pieces, you will find the sections have splines. If your crank was clean (not rusty), the pieces will go back together if you use care and some alignment method (e.g. precision v-blocks). Attempting to rebuild one crankshaft can be time-consuming and expensive. When I used to buy the new cranks from Honda, they rose in price from $150 to $1500 in the span of time from 1975 to 1990. At the end, they really wanted you to buy a new car. Gee, in 1975, I could buy a piston kit from Honda for $25 which contained 2 pistons, 2 sets of rings & retainers, and 2 wrist pins and I had a choice of 5 piston diameters. At least computers are cheap now. good luck,Dale -----Original Message-----
From: fredz@... [2cylinderhondas]
To: 2cylinderhondas
Sent: Mon, May 13, 2019 6:01 pm
Subject: [2cylinderhondas] Re: Has anyone taken a crankshaft apart? You cannot reassemble the crankshaft if you remove move than just one end or the other (unless you get it done by an experienced motorcycle mechanic/shop who have knowhow & equip) due to the precision required to realign the one end you removed, even though it has fine splines. If the center bearings are worn the rod bearings will be flogged out, so bin it. Even doing just one end, you need Vee blocks and a dial gauge to align it - or the crank will bind, or lock up when fitted.
-
feltonminicycle
- Posts: 352
- Joined: Mon Apr 14, 2003 2:50 pm
Re: Has anyone taken a crankshaft apart?
The early sedans have the smaller crank, easy to tell by the hole part way up through the conn rod.
Miles
Miles