Hard to cold start

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Sb_750
Posts: 8
Joined: Sun Jan 15, 2023 9:33 pm

Hard to cold start

Post by Sb_750 »

Hello I have a bmw r75
I have velocity stacks and a mesh filter and the bike runs perfectly but there is a small issue where it does not start without starter fluid when cold. Once started though it runs perfectly. Hot starts also are easy. Please help thanks
barryh
Posts: 730
Joined: Fri Oct 01, 2010 12:30 pm

Re: Hard to cold start

Post by barryh »

Are the enrichers working ? One possible problem is a blocked jet in the float bowl. Remove the float bowls and you will see the enricher wells into which a long brass tube inserts from the main carb body. At the bottom of the well is a small hole or jet that allows the well to be filled from the float bowl. Make sure that hole is clear which should enable the enrichers to function.
barry
Cheshire
England
Kurt in S.A.
Posts: 1647
Joined: Tue Aug 03, 2010 12:08 pm

Re: Hard to cold start

Post by Kurt in S.A. »

How did it run before the velocity stacks?

Kurt
Sb_750
Posts: 8
Joined: Sun Jan 15, 2023 9:33 pm

Re: Hard to cold start

Post by Sb_750 »

barryh wrote: Fri Jun 09, 2023 7:44 am Are the enrichers working ? One possible problem is a blocked jet in the float bowl. Remove the float bowls and you will see the enricher wells into which a long brass tube inserts from the main carb body. At the bottom of the well is a small hole or jet that allows the well to be filled from the float bowl. Make sure that hole is clear which should enable the enrichers to function.
I will check that now
Sb_750
Posts: 8
Joined: Sun Jan 15, 2023 9:33 pm

Re: Hard to cold start

Post by Sb_750 »

Kurt in S.A. wrote: Fri Jun 09, 2023 10:10 am How did it run before the velocity stacks?
I think it was working fine but it was sitting about a year in between with carbs off
Kurt
Sb_750
Posts: 8
Joined: Sun Jan 15, 2023 9:33 pm

Re: Hard to cold start

Post by Sb_750 »

I fixed it I just blew some air in the thin tube that Leads to the choke still take a couple try’s but it starts now👍thanks
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SteveD
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Location: Melbourne, Oz.

Re: Hard to cold start

Post by SteveD »

Cheers, Steve
Victoria, S.E.Oz.


1982 R100RSR100RS supergallery. https://boxerboy81.smugmug.com/R100RS
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1994 R1100GS.
Tasha 2020
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Joined: Fri Jul 08, 2022 8:28 pm

Re: Hard to cold start

Post by Tasha 2020 »

Another common problem is that the enricher gaskets deteriorate which makes them suck air and not fuel
barryh
Posts: 730
Joined: Fri Oct 01, 2010 12:30 pm

Re: Hard to cold start

Post by barryh »

Tasha 2020 wrote: Sun Jun 11, 2023 1:00 pm Another common problem is that the enricher gaskets deteriorate which makes them suck air and not fuel

Enricher gasket have a bit of a reputation for being pulled in. When I hade my carbs in bits and examined the enricher covers I observed that they were not as flat as they might be. The covers look to be die cast and had not had a machined finish. I wonder if that is why they have gained this reputation. I think it's a worthwhile job to re-surface them using wet and dry on some plate glass. That exercise confirmed that mine were indeed not truly flat.
barry
Cheshire
England
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