By joining you will help ensure that we can continue to provide this service
JOIN HERE!
R51/3-carbs leakage and tuning issues
- Micha
- Posts: 768
- Joined: Fri Oct 12, 2007 2:24 am
- Location: Israel
- Has thanked: 11 times
- Been thanked: 5 times
R51/3-carbs leakage and tuning issues
The bike was a first kick started back then and pulled very well.
Then I let it stand for 4-5 years and now preparing it back for ride again.
Overhauled the engine and gearbox.
Regarding the carbs: Took only apart the covers, slides and floats. Untouching the idle and fuel bolts as I remembered how very well these carbs where tuned.
Cleaned all well and installed back.
In total it is hard to start her, but when running, she's relaxed. However, can't start her with only one cylinder.
The engine idles relaxed like a sewing machine but with the following problems:
I'm getting a massive fuel leak from the left carb idle screw (no. 14 to 17 on Salis picture)
Left cylinder is running much to hot. So hot that it is changing its sound and I have to shut down the engine.
Its exhaust pipe is almost red hot, while the right one is only warm.
Before reading ALL these articles:
http://benchmarkworks.com/articles/howto/carb.html
and
https://bmwmotorcycletech.info/synchcarbs.htm
I'm asking for mercy and would be happy to hear your opinion on what to search after and where.
Thank you in advance!
R51/3 1952
Engine Nr. 529466
- schrader7032
- Posts: 9058
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3-carbs leakage and tuning issues
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
- schrader7032
- Posts: 9058
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3-carbs leakage and tuning issues
If you have fuel flowing out the idle air screw, then the float is not sealing off the inflow of fuel. If the float is not cracked, then something is restricting the float from rising to the top to shut off fuel. The rod that goes through the float might not be in the proper position. The bottom part of the rod rides in a small well at the bottom of the float bowl...sometimes that part of the rod gets stuck in the well due to corrosion.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
- jwonder
- Posts: 784
- Joined: Wed Nov 23, 2016 7:50 pm
- Location: Long Island, New York
- Has thanked: 3 times
- Been thanked: 8 times
- Contact:
Re: R51/3-carbs leakage and tuning issues
Vice President, Vintage BMW Motorcycle Owners
2022 BMW Friend Of the Marque
Long Island, New York
- schrader7032
- Posts: 9058
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3-carbs leakage and tuning issues
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
- Micha
- Posts: 768
- Joined: Fri Oct 12, 2007 2:24 am
- Location: Israel
- Has thanked: 11 times
- Been thanked: 5 times
Re: R51/3-carbs leakage and tuning issues
But, that rod that is going through the float can be swiveled. Is this ok? I mean if it is turning inside the float, how can the last one be air tight?
R51/3 1952
Engine Nr. 529466
- schrader7032
- Posts: 9058
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3-carbs leakage and tuning issues
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.
- Micha
- Posts: 768
- Joined: Fri Oct 12, 2007 2:24 am
- Location: Israel
- Has thanked: 11 times
- Been thanked: 5 times
Re: R51/3-carbs leakage and tuning issues
Bot rods sides are entering/going through the right spots.
The float can be pushed down in the chamber, against the fuel level and it is popping back up when finger removed.
When cleaning the carbs, one of the process was filling up that chamber with vinegar for 24 hours.
I really can't understand where there should be debris. The float's rod is like new (and clean).
Can there be any other reason for that leak?
Thanks a lot all of you for your support.
R51/3 1952
Engine Nr. 529466
- schrader7032
- Posts: 9058
- Joined: Fri Oct 27, 2006 3:00 am
- Location: San Antonio, TX
- Has thanked: 3 times
- Been thanked: 36 times
Re: R51/3-carbs leakage and tuning issues
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.