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Hi Garry, The Flash Lube Valve saver is a good thing when you don't know if the seats have been done. All BMW boxer motors from 1960 to 70 run 6 & 7 heat range depending on compression. All BMW boxer motors from 1970 to 90 run 6 heat range only going up to 7 if
needed. Standard timing is about 7 BTDC. You could move the timing up a bit to 10 BTDC.
& try the BP plugs. Paul.
Definitely try the BP plugs, they help burn off deposits accumulated from low load, low speed stuff without affecting the heat range.
Intetesting re having to lean off for tuning recently that Powerband mentioned.
I am not familiar with that carburettor, but I suspect that (like the 36IV does) fuel is leaking somewhere that is supposed to be sealed. Have a close look at it when you have it apart, and look for things like warped castings so that a seal is not working. Plus, of course, things like split accelerator diaphragms. And look for the possibility of a blocked air passage.
I assume you are certain the float is not perforated and the float valve is sealing?
It would be extremely unusual to have to replace jets on a fixed jet carburettor (unless deliberately changing mixture).
Thanks for those comments - I am going to have to bite the bullet and get the carb rebuilt - have an idea what to look for while it is down.
These BP extended nose plugs - do they physically protrude further into the combustion chamber? If so I am concerned about plug to piston clearance.
Thanks
Garry
John,Quote:
Originally Posted by JDNSW
I am very familiar with this problem with the very carb I have.
When I had it rebuilt a few years back it came back and worked perfectly. The next day it was running really bad with fuel streaming into the carb - I pulled it apart and the floats had fallen apart.
Attachment 153548
Each float is plastic in two halves that are glued together. I contacted the rebuilder who indicated these are not included in the $400 rebuild (WTF) and as they were old, the carb cleaner had dissolved the glue and had fallen apart in the running engine. I reglued these with super glue and worked fine but I got a new set from the US and put them in and seems to be fine now. However I will need to recheck these when the carb is dismantled.
Cheers
Garry
Hi Garry
In all my older vehicles I have been having issues with sparkplugs.
What the manufacturers specs say and what the motor needs these days has changed because the fuel we are now forced to use has changed.
The haffie motor you will have to be extremely careful if going to a hotter plug as the little hard working air cooled donk will be near its limits on a hot summers day under load from a pinging and knock point of view.
Protruded nose plugs are the way to go as they tend to self clean better than other types.
You will have to just carefully try them, or measure piston to TDC to plug thread
Clearence etc.
Your real problem will be the carby needle and seat or float level or faulty float.
The needle and seat following the haffie workshop book should be striaght forward, and on the both the single throat and dual throat haffie carbies I think it can be done in situ and only the top of the carby needs to come off .
The main trick is not losing screws screws in the engine compartment and setting the float hight with the new needle and seat.
Recent examples of trouble I have been having with fuel and plugs.
BSA motor cycle..........plug had to be change from what the makers spec because of the different fuel we have these days...........if the plug is a bit off you really notice it on a single lung pommie thumper.
Studebaker truck with side valve Hercules motor again I had to experiment with slightly different sparkplugs from makers specs............modern fuel again.
101 Landrover.............blackcoated sparkplugs,two on one side of the motor and two on the other side, causing great power loss and changing plugs only cured the problem for a short time.
One carbie was running rich.............pulled both carbys ........a pain in the arse job in a 101 Landy and fitted carby kits and reset float heights.
Modern fuels on vehicles which are not in constant use tend to give the alloys and some plastic materials a hard time.
Modern fuels will attack varnish sealant on cork carby floats and plastic on some plastic floats.
Brass needle seats can corrode too.
On my 101 Landy with the CD 175 strombergs the needle seats were slightly corroded (They were not worn) after 10 years since to last carby kit and caused the black coated fouled sparkplugs.
My Stalwart with its F head motor with electronic ignition and non standard manufactures spec protuded nose plugs was transformed.
With standard plugs and modern fuels I was pulling out and cleaning/replacing sparkplugs all the time...........protuded nose plugs have not been out of the engine since I worked out the correct heat range ect.
You may know this one - but if you take the float out and immerse it in hot water, it will bubble from any leaks.Quote:
Originally Posted by 101RRS
Seems to me that if they knew the floats were old, a word to you to see if they should be replaced at the time would have been in order.Quote:
Originally Posted by 101RRS
I despair sometimes that some companies don't have personnel with some initiative & the ability to use a telephone or keyboard in their workforce.
Just sayin'
Thanks Ron for those insights - as you know my haflinger has a great turn of speed when everything is working - despite the engine failure which was cause by a design fault in the modifications done by the previous owner (piston hitting the head) - all corrected now. Oh the engine failed again before we found out why - all good now.
On the floats - yes John that was how I found out I had an issue first time around - the other clue was petrol inside the float.
4Bee - I do not disagree with what you have said. I was surprised that floats are not included in the extensive rebuild kits. Now as I indicated the carb was fine when I got it back and put it on - it was a day or two later that problems arose. When I spoke to the carb guy he said he did not realise they were a glued float and it would appear his cleaners softened the glue but it still held but in its softened state it could not withstand being soaked in petrol for a few days when reinstalled. Replacements were almost impossible to find - even at the local Mercedes Benz independant (some MBs like Unimog and Porsche use the same carb) didn't have any. I glued the old floats with Superglue and it worked fine. I managed to get some from a mechanic in San Bernardino in the US - but yes you send these to experts who are not experts.
What I am going to do.
So - carb to be dissembled and rebuilt noting the points made in this thread - much appreciated.
Paul I will change plugs to BP and go one hotter but will need to check clearance - NGK BP6HS - I have an Engine Saver so can read the temp of the engine (to address Ron's point) - I know on a 38 degree day the heads are at around 70c and with higher revs (more airflow) temps are lower than low revs (less airflow) so have a benchmark to gauge if the the 6 spark plugs cause the engine to run at higher temps.
Thanks for all the great information - I got more information here than posting the same basic issue on Haflinger and Pinzgauer forums - very much appreciated - confirmed what I was thinking and gave new things to think about,
Cheers
Garry
