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Post by canuck on Dec 16, 2022 17:13:46 GMT
Dec 13, 2022 13:33:59 GMT -5 jonnyb said: "However, I think the choke system on the H4s isn't functioning properly. The choke operation is very stiff, even with a new cable, and I suspect the jet movement is perhaps stiff due to the cork seals, which I believe go hard? I have made a wooden former to bolt onto the fronts of the carbs so I can remove them and investigate while they are held in their correct respective positions by the former. No point in tuning carbs until I know the choke operation is correct. Also need to look at high speed idle as cam does not seem to be giving much effect with choke operation.
Thoughts/advice welcome as usual."
Johhny, I thought it best to start a new thread as your request may be hidden in the other thread I suffered the same malaise for years with mine. My cable felt like I required two draught horses to pull it. First off I changed out a mangy aftermarket cable, and routed it properly through the bulkhead. Ensure your linkage is correct on each carburetter and the spring, (Thackery) washer is allowing easy movement of the cam. The lever between the carburetters can also give grief. Ensure it is adjusted and the metal dead end is clamping properly. salut Bruce
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Post by jonnyb on Dec 16, 2022 18:22:31 GMT
That is great Bruce, thanks. Yes I think a new thread makes sense, especially for people searching in future. I initially thought it was the cable; it was very mangled at the carb end and the outer had kinks in it. However, having fitted a new one it was still stiff. So next job will be to remove the carbs and check all the linkages and jet movement. Thanks for the pics. I'll report back when I get to it. I have seen comments about the cork seals causing issues and Burlen have a kit for the H4s which use "rubber" seals. Anyone used them?
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Post by canuck on Dec 17, 2022 15:21:50 GMT
Johnny Keep in mind that the 'choke' levers have designed in lost motion, hence what appears to be oversize holes. This is intended. As well these brass levers clean up to be lovely. I have not seen a reference to replacement seals for the cork glands. The MGA chaps use some sort of teflon ring etc. If you search about MGA forums you will find this well discussed. What is often the case of dripping jets is these cork seals dry out and need renewal. Of course they are to be soaked in oil 24hrs prior to install. I have been successful to be drip free, (my carburetters ) +10 years so I stay with the cork. By this time the carburetters are due for a bath anyway so seals and gaskets are a wholesale change. I have rebuilt a great many of these H type carburetters and noticed frequently that the jet spring can be worn and not provide the adequate pressure to the glands to their receiving washers . I suggest when you dig in there to fit new springs to ensure no drips. Burlen offer a 'Superdry' kit that includes swapping the complete jet bearing etc. I have heard nothing but praise for these kits but I am too cheap to fit them. salut Bruce
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Post by jonnyb on Dec 17, 2022 17:30:31 GMT
Yes that "Superdry" kit was what I was referring to, but quite expensive! Thanks for the other tips. Not sure when I'll do this but will post when underway.
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Post by vue from the north on Dec 21, 2022 22:35:14 GMT
i know this may sound silly but i recall on a 1.5 hard choke pull & hard ish to start turned out only 1 carb was choked ! fixed it & was good & easy after
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Post by jonnyb on Jan 24, 2023 14:35:40 GMT
Hi All, I have now removed carbs and started investigating. 1.The stiffness in pulling the choke lever seems to be caused by the front carb jet being very stiff. Next I will remove the jet bearing assembly and see how things look. The jet does not appear to be bent and the rear jet moves fairly freely. 2.Bruce I note in your first picture there is a long spring in parallel with the cam link. Mine doesn't have that and it doesn't seem to be shown in the picture of the carbs in the Service Parts List, but I can see it might assist the operation of that cam. 3. The Service Parts List shows an aluminium washer between the cam and the carb body. Mine doesn't have that and Burlen's cam kit doesn't seem to show it either. 4. Bruce in your picture of the carbs the brass choke levers are cranked, same as mine part no AUC4040/41, but your later pic shows the other levers part no 5091/92. Are these interchangeable and have you a pic of them fitted to the carbs?
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Post by canuck on Jan 25, 2023 14:37:36 GMT
Hi All, I have now removed carbs and started investigating. 1.The stiffness in pulling the choke lever seems to be caused by the front carb jet being very stiff. Next I will remove the jet bearing assembly and see how things look. The jet does not appear to be bent and the rear jet moves fairly freely. 2.Bruce I note in your first picture there is a long spring in parallel with the cam link. Mine doesn't have that and it doesn't seem to be shown in the picture of the carbs in the Service Parts List, but I can see it might assist the operation of that cam. 3. The Service Parts List shows an aluminium washer between the cam and the carb body. Mine doesn't have that and Burlen's cam kit doesn't seem to show it either. 4. Bruce in your picture of the carbs the brass choke levers are cranked, same as mine part no AUC4040/41, but your later pic shows the other levers part no 5091/92. Are these interchangeable and have you a pic of them fitted to the carbs? Jonathan, First off let me apologize for the confusion I have sown. I used to rebuild carburetters for members and friends and have many archive photos. I will pay better attention next time to post model/type specific photos. 1) maybe this is dried out cork glands. Get some new ones and oil soak them prior to install? 2) that spring was a thought along the lines you write. I will admit the principle looked good on paper but didn't reap the reward I was expecting I removed it shortly afterwards. 3) Yes there is/should be a washer between the cam and the carburetter body. If memory serves this is a 'special' washer? with the hole in this washer allowing the diameter of the shoulder screw to fit through it? The outer Thackery washer is mega important to keep the cam aligned. 4) Good eye. Initially I posted that photo show how the brass bits clean up 'shiny'. In fact these are MGA levers and I did try to fit them to the Riley for a center pull cable. I ran into interference of the float chambers being mounted between the carbutretters and gave up on the idea. You may be smarter than I was and make these work? I show this levers/linkage below Back to you Bruce
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Post by jonnyb on Jan 25, 2023 16:38:40 GMT
Thanks Bruce, as usual very helpful and answered all my questions. I did look at the MGA carb diagrams which shows a bracket for the throttle and choke cable stops but with the central float chambers that would probably cause fouling. I have eased the front jet movement by soaking with oil. Still investigating but will probably refit carbs and retune to see how it goes. The float valve settings were well out and I have reset the float levers using an 11mm drill shank as described in WSM and SU tuning tips book. The Owners Workshop Manual Riley 1.5 and Wolseley 1500 by J.R.S.Hall (which came with the car)shows setting the float level but with 1/8" or 3/16" or 5/16" bar depending whether you look in the text or illustration. Maybe the PO followed that. Also pic shows nylon conical float not brass cylindrical one.
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Post by canuck on Jan 25, 2023 18:29:29 GMT
Jonathan, Be careful. That float chamber lid you show in your post is for a HS type carburetter that our Riley were never fitted with this type. That may be a Wolseley fitment? I have no idea having never seen one. The float level of the H type is set as you mention; This thought may come across as rather cavalier, but why don't you simply unscrew the jet bearing from the carb body and check the glands? I suspect the glands #3 & #7 are dry and giving you grief? Caveat being you may damage the glands beyond use, and you will of course need to re center the jet/bearing at re assemble, hopefully not out of your comfort zone. All good fun Bruce
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Post by jonnyb on Jan 25, 2023 20:52:49 GMT
Jonathan, Be careful. That float chamber lid you show in your post is for a HS type carburetter that our Riley were never fitted with this type. That may be a Wolseley fitment? I have no idea having never seen one. This thought may come across as rather cavalier, but why don't you simply unscrew the jet bearing from the carb body and check the glands? I suspect the glands #3 & #7 are dry and giving you grief? Yes I posted that pic to illustrate that not all that is in print is correct. The book it came from was a forerunner of Haynes supposedly for Riley 1.5 and Wolseley 1500 but that pic was the only bit on float level setting and is wrong for the Riley. I did set it as you show from the SU book.
No not cavalier, I did dismantle the jet bearing assembly, with my reading glasses on, and soaked glands in oil which has helped a bit but still not as good as the other one. Will be ringing Burlen in the morning to order glands. Springs etc all seem to be good.
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Post by canuck on Jan 27, 2023 22:25:21 GMT
Yes I posted that pic to illustrate that not all that is in print is correct. The book it came from was a forerunner of Haynes supposedly for Riley 1.5 and Wolseley 1500 but that pic was the only bit on float level setting and is wrong for the Riley. I did set it as you show from the SU book.
Jonathan, Your comment twigged my memory, thanks. I do have a BMC factory Workshop Manual service publication #AKD4095A that covers both the Wolseley & the One-Point-Five. Mega confusing if one doesn't pay attention. In the fuel section both models and the fitted carburetter types are covered. Separated only by paragraph, for the un initiated could confuse. FWIW the more pedestrian Wolseley had a single H2, (Yikes) and later a HS2 (double Yikes!) fitted . We chose well with the Riley. salut Bruce
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Post by jonnyb on Jan 31, 2023 16:24:07 GMT
Well I have now nearly completed this job. On the front carb the jet was stiff in the bearings which was causing the high force needed to pull the choke lever. When I dismantled the jet bearing assembly it had cork seals and I know these were renewed by the previous owner. So I bit the bullet and ordered the newer Superdry jet bearing assembly from Burlen with the rubber seals. These are now fitted and the choke operation is much smoother. Having set the float levels by the SU book, rather than the incorrect original setting and set the jet levels relative to the bridge and centred the jets, I put the carbs back on the car ready for engine start. Completely dead! Petrol was arriving at the float chamber head but not getting into the jets. I wondered if resetting the float levels had caused the float needles to remain closed. Off came the float lids and as suspected the float chambers were dry. In fact both needle valves, whilst sitting dry, had stuck shut and after removal and a bit of jiggling started to work properly. These were new viton tipped needles put in by the PO. Today I have had the car running and done an initial tune to get the carbs balanced and mixture set and it is running well. Next phase is tappets and timimg followed by a final carb tune. As an aside having got used to a chrome bumper MGB with HS4 carbs the choke arrangement on the Riley H4 carbs is very primitive. On the MGB as the engine warmed up you could push the choke part way in losing most of the enrichment but retaining the high speed idle. On the H4 carbs you lose the high speed idle as well as the enrichment simply because of the way the high speed idle is dependent on the jet lever position. I do like the Riley though in spite of/because of its quirks. It is far superior to my first car, a 1934 Austin Seven, bought when I was 18, but I loved that too!
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Post by canuck on Feb 3, 2023 13:58:46 GMT
In fact both needle valves, whilst sitting dry, had stuck shut and after removal and a bit of jiggling started to work properly. These were new viton tipped needles put in by the PO. As an aside having got used to a chrome bumper MGB with HS4 carbs the choke arrangement on the Riley H4 carbs is very primitive. On the MGB as the engine warmed up you could push the choke part way in losing most of the enrichment but retaining the high speed idle. On the H4 carbs you lose the high speed idle as well as the enrichment simply because of the way the high speed idle is dependent on the jet lever position. I do like the Riley though in spite of/because of its quirks. It is far superior to my first car, a 1934 Austin Seven, bought when I was 18, but I loved that too! Hello Jonathan, Nice to read you spent some money, can't take it with us right? The Superdry jets look a good bit of kit. These Viton tip fuel valves are a PITA as you found out. I have experienced the same as you and even complained to Burlen. They said once the tip is fuel lubricated all will be fine. Not the case in my garage. I re installed the OE metal tips fuel valve and haven't looked back since, >35K miles. Odd you mention the 'advanced' design of the HS type choke, I see these two types similar. I think either is a prehistoric design having to move the jet to add more fuel. I prefer the later iteration enrichment device used on the HIF type, very modern and foolproof. FWIW both H & HS types carburetter choke mechanism should work the same no?. The lost motion of the choke levers for the Riley should move the cam first then the jet lever? Have you set your fast idle screw correctly? I am sure you know this but this should be done on independent carburetters then snug the joiner. Maybe I have this wrong on this, I am not near my car to check, but I know I am able to reduce the choke once the engine is started. B
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Post by tonyhosk on Feb 23, 2023 22:12:28 GMT
Bruce A query on a similar theme to this thread. I have just rebuilt the carbs and refitted. I have noticed that the rear float chamber cover has a small hole in it, not present on the front one and not something I recall from other SU carb set-ups I have worked on. Is this correct and, if so, why? Does it help fuel passage to the rear carb chamber? Tony
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Post by 2robert4 on Feb 24, 2023 9:01:59 GMT
In my humble opinion the hole should not be there the overflow pipe serves as a breather to let the air out as the fuel is allowed in so there is no need for an extra hole. Hope this info is of some help?
NP
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