Author Topic: Carby ??  (Read 7684 times)

cobbadog

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Re: Carby ??
« Reply #15 on: 29 October, 2019, 09:20:32 pm »
It does seem to hold pressure for the short time, 30 seconds before I release it with the button so I think that the valves and rings seem to be ok.
As for any leaks caccuum or exhaust I cannot hear any and a spray of start ya bastard does not alter the revs so its not sucking in air anywhere along the manifold or the flange gasket to carby.
So it can now sit around untl the new needle n seat arrive and start again.
Cheers, John & Dee. Coopernook. NSW.

asw120

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Re: Carby ??
« Reply #16 on: 30 October, 2019, 07:54:21 am »
If it's like most compression testers, that valve is to hold the pressure in the gauge so you get time to read it.
I don't think even good cylinders hold pressure very long.

Jarrod.

cobbadog

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Re: Carby ??
« Reply #17 on: 30 October, 2019, 04:24:22 pm »
Apparently these are good numbers. Formula offered up to me was air pressure x 4.7 which is the compression ration.
14.7 x 4.7 = 69.09 psi and I have a good average above that at 74.25 psi. This may now be considered to be a high performance engine with a ratio like that!
New needle and seat arrived today from Classic Carbs on the Gold Coast. It is a genuine Zenith part which fits the Solex perfectly. It also came with a choice of 2 thicknesses of fibre gasket to adjust the fuel level. Tomorrow hopefully I will put it back together and see what happens.
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #18 on: 30 October, 2019, 09:19:26 pm »
Scotty also offered up the idea of checking valve clearance especially on #3 as the problem got worse as time went on, heating up more.
Time will tell I guess.
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #19 on: 31 October, 2019, 04:57:09 pm »
I have been using that "doing word" an awful lot but then I always do anyway, so nothing has changed.
So, just for everyone's amusement I got to have a short play with it today.
Fitted the new needle and seat using the thin washer. Then as described in the manual remove the main jet and with the top half of the carby bolted to the manifold and connected to the fuel supply and throttle linkage you can then swing the bowl out towards you and then turn on the fuel and watch where the fuel level comes up to. Right on spec, it stopped about 2-3mm from the top of the jet holder. Beauty one mate, I'm winning and all that stuff. Screwed the bowl back on and turn the fuel on and I waited and all seemed good, no fuel dripping out. Tried a start up and no go. then while switching off the ignition fuel starts dripping out. "LOTS OF DOING WORDS RIGHT AT THIS MOMENT"
Removed the bowl and fitted the thicker washer but still dripped. Then I noticed the float has a small dent in the top and I am now thinking that this might be the cause of it not shutting off properly all the time.
So I am chasing a new float for the Solex 30-FV if anyone has one, it should have 26 gm (26 grams) stamped on top. You can just see the small dent on the top and I dont want to be the one to try and take the top off the float, knock the dent out and try and put it back together. I just know what will happen.
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #20 on: 02 November, 2019, 03:45:36 pm »
In today's episode, we explore the internals of the engine. I pulled the rocker cover off and checked the clearances of the valves. A couple were slightly tight but still had plenty of clearance when running warm. So I went through all of them and checked the gaps and made them as specified. Typical Pommies don't give you a COLD setting only HOT so at the moment they are set cold to the gaps suggested. I lost spark at one stage and went hunting and in the end I looked closely at were the power enters the dizzy. The bolt ran close to ground so I put a short piece of insulation under it and that appears to have solved that problem. I did have a go at the float. I opened the hole at the bottom of the float and used a piece of fencing wire, (the most handiest tool on a farm) to push up the small dent at the top. I did have to bump it a little with a hammer but got it up fairly close. So with the rocker cover off I did a start up and took this video. It still does not run smooth and with out touching anything it occasionally picks up the revs slightly and goes back to running rough again. If I pick the revs up a little the engine still runs rough but not as bad but then spreads the love of oil to everyone nearby.


https://youtu.be/oZI-Ga7_UGQ
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #21 on: 03 November, 2019, 02:19:54 pm »
All sorts of things have been going on and each time directing you to the opposite side of the engine. Today after re-doing the valve clearances to Exhaust 0.022" and Inlet 0.015" I did find 2 that were tight but not that tight I could not get the feeler gauges in so I backed them off ever so slightly. While running the engine with the cover off you can see in the video a large amount of oil running out of the rocker shaft at the mid point. This is where the front and rear shafts meet and then there is a small lock screw to hold it into the post. On top of the post there is a hole with no thread and you can see to the bottom of the shaft when the engine is off and the oil drained out. I thought this was a waste of good oil pressure because if I put my finger over this hole more oil went to the rockers were I feel it is suppose to go to. So I made a modification by dropping a small bolt down the hole but not fr enough to block the hollow in the shaft and then wired it in place. Now more oil goes to where it is supposed to go to and the rockers will be happier.
I did borrow a carby today off a mates known to be good tractor and bolted it to mine. It pretty much started up just as normal, easily, but went straight to this uneven running as if spark was the issue. So I went and started pulling the HT leads off one at a time and pushing them back on. # of the 4 virtually made very little difference as to how it was running. When I went to push the lead back on a huge spark jumps across to the plug and for a moment that plug would fire then stop again. So I replaced the 3 plugs with some of the old ones I took out and this improved matters a lot but then I was back over to the carby as the engine was hunting a little bit. At this stage no black smoke at or near idle or at revs so that is good. So I started adjusting the spring tension on the throttle linkage between the governor to the throttle main shaft and I have managed to settle that down to running constant. Back to the air mixture to try and get rid of a flat spot and so far no joy but it is very small and although I have not driven it as yet the flat spot is the least of the issue.
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #22 on: 04 November, 2019, 04:22:42 pm »
The engine is now running far better with room for improvement. I fitted up the borrowed carby and started the engine. It was missing on a number of cylinders but had a huge spark at each plug and only 1 1/2 cylinders appeared to be firing. Swapped over the ones not firing well with 3 old plugs and it this improved things but still not happy. dug out the timing light and removed the cover on the bell housing and turned the engine over to approaching TDC and the marks were coming up. The manual says to put the letter "M" in the centre of the hole, I have no pointer on mine, and at this point the points should be just breaking but mine were opened more than 'just'. So using a test lamp I loosened the distributor bracket and rotated the it back so that the light was on and slowly rotated the distributor until the light just went out. At this stage this is where the manual tells you to set it to and should be 7' BTDC. It started up ok but was occasionally back firing through the exhaust so I moved it a little bit and until the engine sounded as smooth as it could be at this stage. I lock it up at this point and went back around to the carby where on full throttle the engine was not too bad but at idle it was not quite so good and I moved the mixture and got it as good as it could be. Came back after lunch and swapped the carby over to using mine. Started ok, idled sort of, very little black smoke but on full throttle the revs were up and down so I adjusted the spring tension on the throttle linkage and this settled down nicely to a constant running engine at full throttle. Back it off to idle and got a back fire through the exhaust but at least it was now idling with almost no smoke but when I pulled the throttle on full and fast there is a hesitation. This to me is a mixture problem but no matter where I adjust the mixture screw it made little difference but I have found a spot where it is at the least amount. I drove the tractor up and down the drive way but this is not good enough to test it so will do a road run tomorrow and see where I am at.

I did end up with my timing light connected and managed to get the light around the engine to the inspection hole on the opposite side and reading from #1 HT lead I do not see any marks on my flywheel. The same goes on the other 3 leads, any clues on this one?
Cheers, John & Dee. Coopernook. NSW.

franco

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Re: Carby ??
« Reply #23 on: 05 November, 2019, 10:28:13 am »
QUOTE: I did end up with my timing light connected and managed to get the light around the engine to the inspection hole on the opposite side and reading from #1 HT lead I do not see any marks on my flywheel. The same goes on the other 3 leads, any clues on this one?

Flywheel not correctly aligned with crankshaft? I have struck this several times on old vehicles where the flywheel had been removed at some stage and replaced incorrectly,  i.e. not aligned with the correct holes on the crankshaft flange. I suspect this might have been done deliberately sometimes on 4 cylinder engines with 6 crankshaft flange bolt holes to make use of an unworn section of the starter ring gear where the starter normally engages it.

Frank.
Cairns, Queensland

cobbadog

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Re: Carby ??
« Reply #24 on: 05 November, 2019, 09:55:31 pm »
Hi Franco,
This one can only go on one way, it's not an option to re-position it. But a similar problem happened up the front end. Atone stage a bolt inside the timing cover came out and went through the timing gears. It damaged a couple ot teeth on the governor gear and must have destroyed the cam gear as the original timing mark on the cam gear is way out. I noticed this when I was tripping the engine down and fortunately I marked it correctly. I since found that this gear belongs on a diesel model not TVO. But that worked well when it went back together all that time ago.
The dizzy on this is not unlike an early Ferd, it can only go in one way but you must align the drive lug with the oil pump. So at worse it can only be a few degrees out but has a huge adjustment by undoing the clamp on its base. So the next step is to lift the rocker cover again and makes sure it is on compression, get the letter "M" in the middle of the hole at the flywheel and ensure that the rotor is facing #1 position on the cap with the points just breaking.
Cheers, John & Dee. Coopernook. NSW.

cobbadog

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Re: Carby ??
« Reply #25 on: 07 November, 2019, 04:29:25 pm »
Well I went way back to the beginning of the basics even looking under the base plate of the dizzy and found the bob weights were free and in working condition so this was sorted. Re-assembled the dizzy and checked that I was at the "M" mark on the flywheel which gives me 7' BTDC and on compression stroke with both valves fully closed. Gaped the points to 0.012" and connected the test lamp to find where the points were just breaking and the light goes out, locked in place. Again cleaned the plugs check the gap at 0.022" and replaced them along with the HT leads. Went around and switched the fuel on waited a bit to see if any leaks came along then started the engine, broom broom. Let it run for a while and connected the air cleaner back up and a slight tweak with the mixture screw and ran it at various revs. Still a tiny bit rich at idle but after all this crap I am happy with that. Took it out for a road test and it went well. About a 15 minute run was enough to say that it is running and almost better than before the paint job. The governor seems a bit slow in opening and I am not sure if this is an adjustment or a throttle linkage issue but it still went well pulling away easily up a steep hill at very low revs in H 3rd so this is a good thing. I finally found the markings for this dizzy, it is a CA10 model made in 11/53. Will do a bigger road run when we get back from a short break but it should be all good.
Thanks to all replies and ideas in helping to solve this issue.
Cheers, John & Dee. Coopernook. NSW.

wee-allis

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Re: Carby ??
« Reply #26 on: 16 December, 2019, 08:58:08 pm »


John, not related to this or any post, but I've sent you a PM.
Cheers,
Steve.
If it's old, treat it like gold.
 38 Allis B,50 Morris Six,  Moruya, Sth coast NSW.

cobbadog

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Re: Carby ??
« Reply #27 on: 16 December, 2019, 09:36:21 pm »
Thank you Steve. Message received and understood plus replied to in a positive way. Thank you once again.
Cheers, John & Dee. Coopernook. NSW.

shubys tractor farm

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Re: Carby ??
« Reply #28 on: 06 January, 2020, 05:53:56 pm »
I have over 30 DB's - almost all models up to the white units. First thing I would check is the fuel tank. Most times -  they are full of sediment and that blocks a vertical sieve on the outlet inside the tank.  IT IS THE FIRST THING I DO WITH THESE TRACTORS----TAKE OFF THE FUEL TANK AND CLEAN IT OUT COMPLETELY.  Perhaps try that (If not done all ready. Happy new year to all ---------------
Shubystractorfarm.

cobbadog

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Re: Carby ??
« Reply #29 on: 06 January, 2020, 09:34:12 pm »
Thanks shuby but further back in the thread the tank was removed and fully treated with the KBS fuel tank cleaning and sealing kit so is spotlessly clean inside, probably better than new.
What ever was pissing it off seems to have almost gone away now. Still need time to go out on another run to see what happens but lately it is getting way too hot and all too soon weather wise plus even though I could do a road run I dont want to start any more fires around here.
Thanks for the input though.
Cheers, John & Dee. Coopernook. NSW.