Sam.
Can't get it started... some but little spark.
If your interested, I have some out of the box suggestions. I too rebuilt a ca95 engine and installed new guides, valves, piston & piston rings and the motor smoked!
1. Were you aware that the piston rings must be installed in the proper sequence and each in the correct vertical position? Also the rings have to be staggered as to prevent a passage? If not, check the rings before doing the head.
2. Are you running straight 30wt oil? I used shell rotulla (sp) 30 wt diesel oil in my old Hondas. The diesel oil still has the anti-scuff additive that the modern automotive and cycle oils do not have. Multi weight oils will breakdown in the old air cooled hot motors of yesteryear.
3. I normally don't suggest addtives, but the Bardol (sp) NO SMOKE additive works to reduce oil burning. Use this addtive in ratio to your crancase volume. I have used this product in the CA95 engine.
just a thought
1. Were you aware that the piston rings must be installed in the proper sequence and each in the correct vertical position? Also the rings have to be staggered as to prevent a passage? If not, check the rings before doing the head.
2. Are you running straight 30wt oil? I used shell rotulla (sp) 30 wt diesel oil in my old Hondas. The diesel oil still has the anti-scuff additive that the modern automotive and cycle oils do not have. Multi weight oils will breakdown in the old air cooled hot motors of yesteryear.
3. I normally don't suggest addtives, but the Bardol (sp) NO SMOKE additive works to reduce oil burning. Use this addtive in ratio to your crancase volume. I have used this product in the CA95 engine.
just a thought
Thanks Spokes!
Yes, the rings were installed with the opening 120 degrees (approx) from each other. The one problem I found after the fact and some research in manuals is that I have the top and middle rings switched. When I installed them, I had no manual and my helpful father in law said that was the way. Since the rings were the same thickness, I had a 50% chance of doing it right.
The other thing I found out in the manual also is that one of those rings (the middle one I believe) has a chamfered edge, and I may not have noticed that at installation time also.
I did add some Bardal No-Smoke but did not seem to do much. The oil in there now is a 10W40. I should change to the diesel as you recommend.
Still in the end, the engine comes off and gets opened again. I will remove the rockers and valves this time and check everything, but after my in-laws leave this weekend!
Thanks
Yes, the rings were installed with the opening 120 degrees (approx) from each other. The one problem I found after the fact and some research in manuals is that I have the top and middle rings switched. When I installed them, I had no manual and my helpful father in law said that was the way. Since the rings were the same thickness, I had a 50% chance of doing it right.
The other thing I found out in the manual also is that one of those rings (the middle one I believe) has a chamfered edge, and I may not have noticed that at installation time also.
I did add some Bardal No-Smoke but did not seem to do much. The oil in there now is a 10W40. I should change to the diesel as you recommend.
Still in the end, the engine comes off and gets opened again. I will remove the rockers and valves this time and check everything, but after my in-laws leave this weekend!
Thanks
It's very important that the rings go in the right way, as you have found out, the top ring is not the same as #2 and they can be put in upside down, didn't know that you hadn't got a workshop manual.
Has the forum been down? I've not been able to get on for quite a while.
I've been off work for three weeks and my internet at home can be slow at the best of times but I couldn't get on here. It was that slow this morning, I deceided to call into work and all seems fine.
Sam.
Has the forum been down? I've not been able to get on for quite a while.
I've been off work for three weeks and my internet at home can be slow at the best of times but I couldn't get on here. It was that slow this morning, I deceided to call into work and all seems fine.
Sam.
Valve guides are in...but!
Hi
I got the intake valve guides in today and first thing I did was to compare them with the ones out of the head. Well, they don't match!
First, they are too long, about 1/2 inch or more, and the grooves for the air hole and the circlip are not spaced appart the same distance. Then, the valve stem does not fit in, only the very tip of the valve before the retainer groove.
Am I missing something? Are valve guides supposed to be machined out to proper size?
The seller on eBay said they were the correct type, but who knows...
I got the intake valve guides in today and first thing I did was to compare them with the ones out of the head. Well, they don't match!
First, they are too long, about 1/2 inch or more, and the grooves for the air hole and the circlip are not spaced appart the same distance. Then, the valve stem does not fit in, only the very tip of the valve before the retainer groove.
Am I missing something? Are valve guides supposed to be machined out to proper size?
The seller on eBay said they were the correct type, but who knows...
srq68 wrote:Hi
I got the intake valve guides in today and first thing I did was to compare them with the ones out of the head. Well, they don't match!
First, they are too long, about 1/2 inch or more, and the grooves for the air hole and the circlip are not spaced appart the same distance. Then, the valve stem does not fit in, only the very tip of the valve before the retainer groove.
Am I missing something? Are valve guides supposed to be machined out to proper size?
The seller on eBay said they were the correct type, but who knows...
Don't even attempt to put them in, you have the wrong ones.
How did you get the old ones out?
Sam.
I just got home and measured a new set of guides.
The inlet guide should measure 29mm long and have an outside diameter of 10.08mm.
The valve wil not fit in the guide as it has to be machined/reamed out to size.
If you have the means to measure the valve stem, I'll post th wear limits for it when I finnish work tomorrow or Friday morning.
How did you remove your guides?
Sam.
The inlet guide should measure 29mm long and have an outside diameter of 10.08mm.
The valve wil not fit in the guide as it has to be machined/reamed out to size.
If you have the means to measure the valve stem, I'll post th wear limits for it when I finnish work tomorrow or Friday morning.
How did you remove your guides?
Sam.
Thanks for those measurements Sam. The ones I got of eBay are 40mm long and 10 mm diameter.
I got the old ones out by heating the head up in the oven to 200 deg and slowly taping them out. They came out effortlessly I would say.
So now I am in the market for valve guides again! This just delays the project, but I want to get it right....
Besides eBay, any good source for those? A couple of OEM parts show them "discontinued"...
So the valve stem has to be reduced to fit the guides, or the guides have to be honed/bored to match the stems? I think I measured the stems at 13/64" or 51 mm.
I got the old ones out by heating the head up in the oven to 200 deg and slowly taping them out. They came out effortlessly I would say.
So now I am in the market for valve guides again! This just delays the project, but I want to get it right....
Besides eBay, any good source for those? A couple of OEM parts show them "discontinued"...
So the valve stem has to be reduced to fit the guides, or the guides have to be honed/bored to match the stems? I think I measured the stems at 13/64" or 51 mm.
There are some on eBay for inlet and exhaust valves but they look different as they have a flange instead of the clip.... Are they correct or a good replacement?
http://cgi.ebay.com/ebaymotors/Honda-C9 ... 3cb1928bb7
http://cgi.ebay.com/ebaymotors/Honda-C9 ... 3cb1928bb7
Yes, the guide has to be honed/bored as you put it once it is in the head.
If you have a manual and can't wait till I dig out mine, you should find the sizes and wear limits at the back of it.
The ones on ebay might be OK but they are from YOU KNOW WHERE
so beware.
When you took out the springs, did you notice a dished washer come out from under the spring (they may still be in the head, sometimes stick).
This is to stop the spring eating into the ally head.
If you use the guide with the flange, make sure this washers hole is big enough to go over the flange and the same for the inner valve spring.
The dished washer needs to contact the head and the springs need to sit on it without coming into contact with the flange.
Sam.
If you have a manual and can't wait till I dig out mine, you should find the sizes and wear limits at the back of it.
The ones on ebay might be OK but they are from YOU KNOW WHERE
so beware.When you took out the springs, did you notice a dished washer come out from under the spring (they may still be in the head, sometimes stick).
This is to stop the spring eating into the ally head.
If you use the guide with the flange, make sure this washers hole is big enough to go over the flange and the same for the inner valve spring.
The dished washer needs to contact the head and the springs need to sit on it without coming into contact with the flange.
Sam.
Thanks Sam, this is a learning experience for me as although I messed with cams and valves, I never dealt with valve guides before.
Yes I got the washers for the springs out of the head and I can see how they would have to fit over the flanges of these guides...
I will look for the tolerances...
One more thing: when I put the valves in the old guides, they seem pretty tight, though I did not measure them with a precision instrument. I tried to blow some air through the guides with the valves in them and nothing gets by. Could they be OK after all? I put maybe 20-30 psi through. Is the oil pressure greater than that and pushing oil through the guides?
Yes I got the washers for the springs out of the head and I can see how they would have to fit over the flanges of these guides...
I will look for the tolerances...
One more thing: when I put the valves in the old guides, they seem pretty tight, though I did not measure them with a precision instrument. I tried to blow some air through the guides with the valves in them and nothing gets by. Could they be OK after all? I put maybe 20-30 psi through. Is the oil pressure greater than that and pushing oil through the guides?
No the oil pressure won't be that high in the cam box.
The system works on atmospheric pressure coupled to negative and poitive pressures/pulses in the inlet tract, that's why it's important to get the small holes in the guide to line up with the passage way through the head and out through the breather on the carb insulator. That is the reason for the wire clip round the guide (or the flange on the AM guides) It stops it going to far into the head and when it seats on the aloy, the holes should line up.
There is a chance the guides are not that worn but you may as well replace them while you have it down, after replacing the pistons, it's really the only other thing that can cause it to smoke.
Sam.
The system works on atmospheric pressure coupled to negative and poitive pressures/pulses in the inlet tract, that's why it's important to get the small holes in the guide to line up with the passage way through the head and out through the breather on the carb insulator. That is the reason for the wire clip round the guide (or the flange on the AM guides) It stops it going to far into the head and when it seats on the aloy, the holes should line up.
There is a chance the guides are not that worn but you may as well replace them while you have it down, after replacing the pistons, it's really the only other thing that can cause it to smoke.
Sam.
The inlet valve stem should measure 5.48 to 5.49mm standard and the exhaust should be 5.47 to 5.48mm.
Inside the guide should be machined to 5.5 to 5.51mm in both.
Standard clearance between the valve and guide should be 0.02 to 0.04mm.
If it reaches 0.08mm, time to replace.
Outside diameter of the guide was as I said, 10.04 to 10.05 and should be shrunk fit by heating the head to 250c.
Sam.
Inside the guide should be machined to 5.5 to 5.51mm in both.
Standard clearance between the valve and guide should be 0.02 to 0.04mm.
If it reaches 0.08mm, time to replace.
Outside diameter of the guide was as I said, 10.04 to 10.05 and should be shrunk fit by heating the head to 250c.
Sam.
Well, some updates: The smoke is gone!
After waiting to find guides without success, I tested them one by one with their respective valve: I put 40 lbs or air pressure in them and inserted the stems: no leak of air whatsoever, so I decided to put them back in. Heated up the head to 250 and put the guides in the freezer. They went back in effortlessly, light tapping to get them seated right.
I closed the engine, verified that the rings all had the numbers facing up and were 120 degrees from each others openings.
Started the bike, it sputtered for a while and then revved up, no smoke at all!
So I believe that the #2 piston middle ring was on upside down and was letting oil by into the chamber.
I wasted time but in the end the head got a thorough cleaning, the valves and cams too.
I have to play with the ignition timing now, as I get some pinging in the #2 cyl. I had to get new plugs since one had a broken ceramic also.
I'll play more with it this weekend....
Next: rebuild the clutch that does not budge.....
Thanks to all for the help!
BTW: I could not get on the forum the past 6-7 days....."404 not found" error.
After waiting to find guides without success, I tested them one by one with their respective valve: I put 40 lbs or air pressure in them and inserted the stems: no leak of air whatsoever, so I decided to put them back in. Heated up the head to 250 and put the guides in the freezer. They went back in effortlessly, light tapping to get them seated right.
I closed the engine, verified that the rings all had the numbers facing up and were 120 degrees from each others openings.
Started the bike, it sputtered for a while and then revved up, no smoke at all!
So I believe that the #2 piston middle ring was on upside down and was letting oil by into the chamber.
I wasted time but in the end the head got a thorough cleaning, the valves and cams too.
I have to play with the ignition timing now, as I get some pinging in the #2 cyl. I had to get new plugs since one had a broken ceramic also.
I'll play more with it this weekend....
Next: rebuild the clutch that does not budge.....
Thanks to all for the help!
BTW: I could not get on the forum the past 6-7 days....."404 not found" error.