Latest topics
» VILLIERS 1H
Today at 9:30 am by kerabo

» 8e gear lever
Yesterday at 1:45 pm by kerabo

» help wanted
Tue Jan 16, 2018 8:20 pm by Dickey0-1

» Cruiser 75 Generator Coils
Tue Jan 16, 2018 7:38 pm by peter@dunfordconstruction

» ITEMS FOR SALE OR WANTED
Mon Jan 15, 2018 6:31 pm by bill2b

» Contact breaker screw
Mon Jan 15, 2018 4:30 pm by kerabo

» Pub meet FFOC welcome
Mon Jan 15, 2018 3:32 pm by kerabo

» Newbie Here
Mon Jan 15, 2018 8:56 am by mikes

» New 17T / 20T piston for sale.
Sun Jan 14, 2018 8:38 pm by rob spence


Cruiser 80 - Carb leaking fuel through the air intake

View previous topic View next topic Go down

Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Sat Jul 11, 2015 9:32 pm

Hi Guys,

I've been riding bikes for a long time but have only recently got in to classic bikes. I bought a cruiser 80 with an AMC 250 about 6 months ago, but it had been previously restored but quite poorly. It ran but very rough when I went to pick it up, and died every time throttle was applied. Since I got it home it didn't start, and still won't. Fuel appears to be leaking out of the air intake of the carb which is odd. I have checked the float and it's not stuck so i'm not sure how the fuel is getting out there, but it's a lot? It doesn't appear to be leaking out of any other location.

Any ideas on why the engine was running rough, when it was actually running and now won't, and why its leaking fuel from the air intake?

I'd like to try and get it up and running but i'm still a little confused as to the issue or how to resolve it. Any idea's?

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

fuel leak

Post  piston 197 on Sun Jul 12, 2015 4:23 am

If fuel is leaking from carb intake then the fuel level must be massively high ? even if the float is not sticking ,the fuel cut off needle must not be working, best thing to do is to dismantle and check this first before you go any further, if in doubt make up a plastic/Perspex float bowl end cover and then you can see what is gong on inside.
JH
avatar
piston 197
Moderator

Posts : 3716
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Carb

Post  kerabo on Mon Jul 13, 2015 7:46 pm

Is that the Monoblock?

If so the level is the DOT in the middle of the word AMAL on the float chamber cover.
I have a cover with a small hole in that place for setting up .
Dont go too low or you will have to flood it every time to start.

Ken
avatar
kerabo

Posts : 2182
Join date : 2008-02-11
Age : 67
Location : Falcon 87. Trials 93 Special. Powerbike 56. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  banjo boy on Tue Jul 14, 2015 12:24 pm

Hi
Check that the previous owner has not gone and put a fibre washer under the float needle housing which screws in to the body if it has, remove it as it will raise the housing and will not allow the needle to shut off the fuel and will blow it out of the carb as you have said, this happened to me until I noticed and now runs a dream.

Laurence
avatar
banjo boy

Posts : 240
Join date : 2013-10-22
Age : 53
Location : cambridgeshire

Back to top Go down

flooding

Post  keith.hodgenia on Tue Jul 14, 2015 2:43 pm

making a perspex float bowl cover was a good aid to setting up float level in the past. in the light of ethanol's ability to dissolve most plastics I would check to see if perspex is stable with petrol before you put too much effort into making one.

keith.hodgenia

Posts : 124
Join date : 2011-06-28
Location : Wirral. model 14, model 4 and 2 big boxes of bits.

Back to top Go down

dissolving plastic

Post  piston 197 on Tue Jul 14, 2015 3:01 pm

Keith, Ethanol is a right B***er, but it's rate of decay of all things rubber/plastic is not so rapid as to dissolve it in the brief time it will be used as a viewing window into the inner workings of MrAmal's finest, it takes weeks /months to make any appreciable difference
JH
avatar
piston 197
Moderator

Posts : 3716
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

ethanol

Post  keith.hodgenia on Tue Jul 14, 2015 3:36 pm

fair point john.

keith.hodgenia

Posts : 124
Join date : 2011-06-28
Location : Wirral. model 14, model 4 and 2 big boxes of bits.

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Fri Jul 17, 2015 12:38 pm

Thanks for the advice. I haven't had time to take a good look yet but having opened up the float chamber again there is what appears to be a fixed white washer In there with a small hole but I am unable to see the needle so I'm guessing it's the same problem you had Lawrence. I'll remove it and replace the needle I'm there anyway and see if I get any luck.

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

white washer

Post  piston 197 on Fri Jul 17, 2015 1:12 pm

If the flat white washer is beneath the fuel banjo ? it is supposed to be there and is the filter that prevents debris finding it's way into the carb, there should be no washer between the large hex nut and the carburettor body.
so parts order are carb body, hex bodied needle seating, white plastic filter, banjo, fibre washer, male securing bolt.
JH
avatar
piston 197
Moderator

Posts : 3716
Join date : 2008-08-17
Location : ross-on-wye

Back to top Go down

Carburettor

Post  kerabo on Fri Jul 17, 2015 3:17 pm

From memory the housing with the seat in for the needle has a washer under it.   The plastic washer is part of the strainer is inside and the banjo
I had to flat off that washer  to get the level correct.
Regards Ken
avatar
kerabo

Posts : 2182
Join date : 2008-02-11
Age : 67
Location : Falcon 87. Trials 93 Special. Powerbike 56. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

Carburettor

Post  kerabo on Fri Jul 17, 2015 4:01 pm

You should be able to see the needle sitting on top of the float. Maybe someone has pulled out the float and lost it .
Anyway all parts available from AMAL and if you look on the site you can choose your bike and see the order of assembly.
Regards Ken
avatar
kerabo

Posts : 2182
Join date : 2008-02-11
Age : 67
Location : Falcon 87. Trials 93 Special. Powerbike 56. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Fri Jul 17, 2015 7:57 pm

Yes the white fuel filter that fits over the needle housing inside the banjo creates a washer between the banjo and the nut of the needle housing. There is another between the banjo and the carb body which I will remove but the actual needle cannot be seen, as there Is what looks like a plug of some sort inside the float chamber covering the needle. As I understand the needle sits inside the housing but should move freely up and down inside the housing along with the float, and the needle should be visible touching the float? Am I correct with this? If this is correct then there are some extra parts attached to this carb which probably shouldn't be there?

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Fri Jul 17, 2015 7:57 pm

Yes the white fuel filter that fits over the needle housing inside the banjo creates a washer between the banjo and the nut of the needle housing. There is another between the banjo and the carb body which I will remove but the actual needle cannot be seen, as there Is what looks like a plug of some sort inside the float chamber covering the needle. As I understand the needle sits inside the housing but should move freely up and down inside the housing along with the float, and the needle should be visible touching the float? Am I correct with this? If this is correct then there are some extra parts attached to this carb which probably shouldn't be there?

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  banjo boy on Fri Jul 17, 2015 8:50 pm

Hi the plug as you say is the needle which does sit inside the housing may be made of brass or plastic and should be visible sitting on the float with the fuel chamber cover off, every thing sounds good apart from the washer that you say is between the hex nut of the housing and the carb body there should be no washer here so once removed this should solve your flooding.
perhapes a picture may help if you still have no luck

Laurence
avatar
banjo boy

Posts : 240
Join date : 2013-10-22
Age : 53
Location : cambridgeshire

Back to top Go down

carburettor

Post  kerabo on Fri Jul 17, 2015 8:56 pm

Sorry but there is a washer under the needle seat nut. If you go to the AMAL site and follow the pages to Cruiser 80 it shows a washer.  I have also bought this washer for my Monoblock on my Falcon 87. Without it the fuel level will be low and possible poor starting without flooding every time .That is unless the float needle or the seat is worn so bringing it back up.
Regards Ken
avatar
kerabo

Posts : 2182
Join date : 2008-02-11
Age : 67
Location : Falcon 87. Trials 93 Special. Powerbike 56. Falcon 81 Green Lane bitsa. Sunbeam S8. Honda Deuville.

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  banjo boy on Fri Jul 17, 2015 9:48 pm

Fair point Ken I am not that familiar with the cruiser carb just going by my carb on my 87 which I had a problem with flooding.looking at my carb main body mine on my bike does not have a counter bore for the washer like it shows on the Amal site which would explain why I removed mine to solve the flooding, having a washer under with counter bore would give the same height.

Laurence
avatar
banjo boy

Posts : 240
Join date : 2013-10-22
Age : 53
Location : cambridgeshire

Back to top Go down

Still no success

Post  Dan792 on Mon Jul 27, 2015 8:28 pm

So initially the carb had been leaking through the air intake for the pilot jets when the fuel tap was open as i mentioned in my first post. Since then i have replaced all the jets, all the gaskets, new float, new needle, new needle housing, new filter, new fuel line, new tap. The carb was taken apart, clean with carb cleaner, ultrasound cleaned and blown through with air. The majority of the problematic parts have been replaced. Today i put the carb back on in the hope that this would have fixed the issue, how ever, in very little time, the carb started leaking again quickly through exactly the same place. My only thought now is that there is a crack possible in the body of the carb that i can't see that is causing the fuel to leak through in to other parts of the carb, causing the fuel to com out the air intake?

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Kim on Mon Jul 27, 2015 9:51 pm

I had a similar problem with my "84". After going through all the normal fixes that have been covered here it ended up being the tickler.
What had happened was the clip on the end of it had slipped allowing the tickler mechanism to seal the hole, this created a sealed float chamber (other than the fuel pipe entry point) . When I turned on the fuel at the tap. The fuel flowing into the float chamber soon pressurized the chamber which then started forcing fuel up the main and (or) idle jet(s) and it would dribble out of the end of the carb.
Worth checking.
avatar
Kim

Posts : 313
Join date : 2011-05-13
Location : Tauranga New Zealand

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Mon Jul 27, 2015 10:48 pm

Hi Kim, that's very odd. I'm not sure I totally understand what the issue the tickler was? Sorry, but could you explain again? How did you resolve the issue? The previous owner has modified the ticker on this particular carb to fit a longer rod on the top, so that may have had an effect on it.

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Mon Jul 27, 2015 10:57 pm

If i'm correct in understanding what you mean, as the fuel is going in to the float chamber, it starts to fill up as normal, until it reaches the upper part of the main jet sump (if thats the correct way to term it), and your tickler was air tight creating a seal, so that there was fuel at the bottom, and an air seal above, meaning fuel continued in as the float was not closing the needle because the fuel level wasn't high enough, but the fuel continued into the carb and of course the only place for the fuel to go was up the jets?

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Kim on Mon Jul 27, 2015 11:23 pm

Yes. When fuel starts to enter the chamber the pressure equalizes by forcing air up the jets (normally this air would exit the tickler). when the jets become covered it starts forcing fuel up them. If that makes sense?
Sorry but I can't remember the exact fix but I think it was reasonably easy. (It was a couple of years ago now)
Mine has the longer tickler rod as well.
avatar
Kim

Posts : 313
Join date : 2011-05-13
Location : Tauranga New Zealand

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Kim on Mon Jul 27, 2015 11:40 pm

It should be easy enough to check. Just remover the tickler assembly and try blowing through it. If you can blow through it, it is not the problem, but if not, I think you might have found the problem.
avatar
Kim

Posts : 313
Join date : 2011-05-13
Location : Tauranga New Zealand

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Dan792 on Tue Jul 28, 2015 12:21 am

Ok thanks, i'll take a look. To be honest the carb has caused me so many problems, i'm considering just buying a new one and replacing it and using the other for spares. The amount of new spares that will end up on this if i keep going will basically make it new anyway.

Dan792

Posts : 10
Join date : 2015-07-11

Back to top Go down

Fuel leaking

Post  keith.hodgenia on Tue Jul 28, 2015 9:20 am

Amal never envisaged a service life of over 50 years. I have fitted new carbs on a number of troublesome bikes the difference in how they ran was well worth the cost. By the time you have unbowed mounting flanges, re-sleeved worn bodies, new slide, new needle the list goes on and on, a new carb is often just as cheap.

keith.hodgenia

Posts : 124
Join date : 2011-06-28
Location : Wirral. model 14, model 4 and 2 big boxes of bits.

Back to top Go down

Re: Cruiser 80 - Carb leaking fuel through the air intake

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum