BritBike Forum logo
BritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorBritBike Sponsor SteadfastCyclesBritBike SponsorBritBike SponsorBritBike SponsorBritBike SponsorHepolite PistonsBritBike Sponsor
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership
Member Spotlight
BeezaBryan
BeezaBryan
Derbyshire UK
Posts: 3,414
Joined: April 2006
New BritBike book out!
ShoutChat
Comment Guidelines: Do post respectful and insightful comments. Don't flame, hate, spam.
Search eBay for motorcycle parts in following countries
Australia, Canada, France, Holland, Italy, United Kingdom, USA
Previous Thread
Next Thread
Print Thread
Rate Thread
#139593 04/18/08 11:22 pm
Joined: Aug 2006
Posts: 258
D
Britbike forum member
OP Offline
Britbike forum member
D
Joined: Aug 2006
Posts: 258
Is it possible to overley sand to much of the carb body surface inside with emory cloth? I Had a sickey slide. I lightley sand off the slide and inside of the body with emory cloth. than i bought a new slide. could i have taken to much surface area off to affect the problem im having with slight popping and acceleration after i left off the throttle? Please read my other thread and let me know if my problem is realated. thank you. Dan

Support Your #1 BritBike Forum!

Check out British motorcycles for sale: British Motorcycles on e-Bay UK, British motorcycles on e-Bay North America
#139594 04/19/08 7:53 am
Joined: Jun 2007
Posts: 6,923
Likes: 16
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2007
Posts: 6,923
Likes: 16
Yes, you could very likely have an air leak causing the symptoms you describe. Send your carb to AMR in Arizona to have a new hard chromed brass Mikuni slide fitted to your rebored carb body and say goodbye to carb problems for a very long time. It's less money than a new carb, but be aware they only do batches of them when they get enough so there could be some delay.
Bill


Bikes
1974 Commando
1985 Honda Nighthawk 650
1957 Thunderbird/T110 "Black Tiger"
Antique Fans: Loads of Emersons (Two six wingers) plus gyros and orbiters.
#139595 04/19/08 10:46 am
Joined: Jun 2006
Posts: 804
Britbike forum member
Offline
Britbike forum member
Joined: Jun 2006
Posts: 804
Emery is far too agressive, use one of the green scotchlite plastic pan scourers used for dishes.


99% of carb problems are electrical.

1959 3TA

BMW R1150 Oilhead
#139596 04/19/08 6:07 pm
Joined: Aug 2006
Posts: 258
D
Britbike forum member
OP Offline
Britbike forum member
D
Joined: Aug 2006
Posts: 258
thanks for the response guys. Is the tolernce for gently sanding the high spots in the carb body that easy to mess up? could this create air leaks? Dan

#139597 04/20/08 3:26 pm
Joined: Aug 2006
Posts: 258
D
Britbike forum member
OP Offline
Britbike forum member
D
Joined: Aug 2006
Posts: 258
RF,are you out there? Dan

#139598 04/20/08 4:02 pm
Joined: Mar 2005
Posts: 10,547
Likes: 43
J
Britbike forum member
Offline
Britbike forum member
J
Joined: Mar 2005
Posts: 10,547
Likes: 43
As the slide is lifted any reduction in vaccum, thus a leaner mixture, caused by a worn slide is reduced. The symptoms of a worn slide are more prominent at lower throttle openings.
So as the slide is raised air leaking around the slide has less and less effect upon the operation of the carburetor.
You don't tell us where the throttle is when you are having these problems. In its simplest form the AMAL works in stages, or jetting circuits. When describing symptoms it is important to relate it to the slide position. This tells us which circuit, or circuits as there is some overlap, is causing the problem.

It is possible to compensate, by changing the circuits involved, to compensate for a worn slide. When you reduce the signal on the jet it is a simple matter of increasing its size. This is exactly what AMAL did when they increased the clearance on the slide to prevent the slide from sticking when the carb body was over tightened.

What a lot of people aren't aware of is, there is a natural compensation for the effects of a worn slide. As the slide wears so does the needle jet. As changes in the diameter of the needle effect the carburation at the same point or circuit were in the slide does, the leaking air around the slide is compensated by the increase in gas flow through the worn needle jet.

When we really start to see a lean problem is when we replace the needle jet and we no longer have the extra gas to compensate for the air leaking around the slide lowering the vaccum on the jet.

The symptoms you offer can be caused by any one of the jetting circuits, or a combination. Thus the bike starting to accelerate a bit as you start to close the throttle above 2/3 - 3/4 throttle could be a sign of a too small main jet or needle set in a too lean position. The same symptoms at 1/4 throttle call for attention to the size of the needle jet and its condition, fuel level in the bowl, a modified cross drilled hole larger than .035", a blocked pilot jet, or air adustemnent screw in wrong position or slide cutaway.

#139599 04/20/08 5:13 pm
Joined: Aug 2006
Posts: 258
D
Britbike forum member
OP Offline
Britbike forum member
D
Joined: Aug 2006
Posts: 258
Hi John. thank you for your listening. I have recently, put a total carb rebuild kit in the carb. I put a new 3 1/2 slide in. I also put a new wiring harnes,tynpanium,and Boyer on my 70 tr6. All of this work has been completed in the last two months. So thats the status of my scoot. As far sa the position of my slide. "ie, seqence".
When i start the bike,it is really hard to start. it fires, than i have to roll the throttle all the way back and forth to keep it running until it warms up. it feels like it dosent advance until it gets warm. i dont have a choke any longer. i filled the hole. once it gets running, it feels fast with a slight popp and mild acceleration after i lift off the throttle. Once running and warm, it idles a liitle ruff even after adjustments to the carb. If i had to say.it feels llike its in the first sequence. but what do i know. thats why im asking for help. so my friends,thats my scenario. please trouble shoot with kindness. thank you. Dan 650-766-1000


Moderated by  John Healy 

Link Copied to Clipboard
Upgrade to: Premium Membership | Gold Membership | Life Membership | Vendor Membership | Site Sponsor Membership

BritBike SponsorBritBike SponsorBritBike Sponsor
Home | Sponsors, Newsletter | Regalia | Calendar | Bike Project | BritBike Museum | Spiders Cartoons, | DVD- Manuals & Parts books
Powered by UBB.threads™ PHP Forum Software 7.7.5