Enjyne troubles...

[Mosin]

Ok, so I finally got everything together, sourced the correct oil, poured it in and wheeled the A7ss outside to give her a kick and see what happened. Essentially, I would have been happy with a bit of a cough and splutter but to my amazement, not to mention that of my wife, the neighbours and the cat, the old girl burst into life on the third kick before settling down to a nice rhythmic tickeover. Not bad for a bike which hasn't been run for about three years!

So anyway, it's helmet on and off for a quick spin up the lane to see how things were looking. All seemed great with no excess vibrations and no significant oil leaks from anywhere. Great that it until she was warm. At this point, the engine seemed to loose power and the throttle seemed much less responsive. she even stalled quite a few times, although it was never a problem to get her started again. The whole thing smells to me of a fuel starvation problem, and it is concieveably possible that some muck may have been sucked down into the carb, but the question is where to start with my investigations? What are the carbs like to work on? Is there anything else I should be checking first? Any thoughts or ideas would be most welcome.

nb. I have checked that there is fuel in the bike and I have checked that the vent hole in the filler cap is clear... so what next?

Simon

[BSA_54A10]

Pull the carbs off get a big pot of boiling water drop 3 or 4 dishwasher tables in there and give them a rolling boil for about an hour.
Remove and give them a rub with a stiff brush then back in the pot for another hour.
Pull them out and rinse twice, once in boiling water and once in cold water.
Usually that will lift most crud.
Then pull them apart and remove any grunge found in there.

[Triton Thrasher]

If it's a Monobloc carb, there's a gauze filter in the feed banjo on the float bowl top.  It gets choked with dirt. So does the one on the fuel tap in the tank, if there is one there.

[Mosin]

Pull the carbs off get a big pot of boiling water drop 3 or 4 dishwasher tables in there and give them a rolling boil for about an hour.
Remove and give them a rub with a stiff brush then back in the pot for another hour.
Pull them out and rinse twice, once in boiling water and once in cold water.
Usually that will lift most crud.
Then pull them apart and remove any grunge found in there.

Thanks for this advice. By happy coincidence my wife is working nights tonight. I feel a nocturnal stint in the kitchen coming on....

The bike just has a single carb and it's not a monobloc. Are they fairly straightforward to strip down? I am always slightly cautious about these things for fear of some hidden spring or something shooting out from somewhere never to bee seen again.


Simon

[69Bonni]

HI There Simon

That'll be Japanese carbs that are full of Nasty little springs balls and valves!

If theres fuel in the lines, take the union off the carb make sure theres fuel flowing (not a blocked tap or something) While the unions off check the strainer filter up in the union housing if there is one. if theres a load of crap in there chances are there might be a build up of crud else where in the carb, fine debris can get past the filter and block the carb jets. if its been laid up a while you may have crud in the tank so it might be worth whiping it off draining the petrol and giving it a clean out with something.... Would have said Parafin but thats as dear as anything nowadays, White Sprit, Turps something like that you can still use it for cleaning brushes afterwards. get one of those nice after market glass bodied fuel filters off fleabay that you can unscrew and clean out at a later date.
Now check your Choke operation and that the choke slide if fitted is opening, probably tight wire is Open! it could be choking the engine to death.

Dish washers and dishwasher tablets are good, slightly caustic they are, misses gave me a thick ear came home early and found my Road Rocket head and Carb in the dishwasher!

All the best Steve

[A10Boy]

Does the dishwasher shift carbon as well ?

[Mosin]

Just finished giving my carb the "dishwaser tablet" treatment and it has shifted absolutely tons of sludge out of it. The little plastic filter underneath the banjo union feed was so clogged up I am surprised that the bike ran at all, and the main jet was clogged too. I am not convinced of the cleanliness of the tank which has recently been resprayed and seems to have quite a lot of paint got into it. I suspect that this has been reacting with the petrol I have put in and has been peeling off which has caused at least some of the blockages. I think that before I reassmble the carb with a new gasket set and re fit it to the bike, I will take the opportunity to fit a couple of inline fuel filters... Much less hastle to replace them than going through this process again after another couple of miles!

Thanks for all the help guys!


Simon

[69Bonni]

Hi Simon, A10Boy

Simon taske a look at these filters on Ebay i use the same type and there quite useful not only can you see inside them, you can also unscrew them and clean them out. I had the same problem with one of my bikes thats why i told you to check the tank, you might also want to unscrew the taps on the tank as you might find the filter gauze on the end of the taps is blocked too.
There are quite a few people selling these on Ebay Item number: 190316402722.

A10Boy, It did a good job on my RRocket head but it was pretty clean inside anyhow, a friend said it cleaned his head right out but i guess it depends how bad it was in the first place, the fins came up lovely. I think BSA_54A10 boiling them would remove it better and the caustic action of the dishwasher tablets will get a fair amount off

Steve

[Mosin]

Hi Steve,

I have just taken the petrol taps out of the tank and was surprised to see that there are no gauze filters fitted, they are just a straight through pipe - no wonder there was so much crap in the carb! Anyway, I think I'll order a couple of the inline filters you suggest and it's probably about time I replaced the fuel hose while I'm at it. I suspect that the hose that is currently on the bike is the original stuff. It's translucent and absolutely rock hard and still fitted with what look like the original crimped unions on each end. Not sure how I am going to deal with them... perhaps just cut them off and use a couple of small jubilee clips to hold the new hose in place.

Cheers,

S.

[Josh Cox]

Hi Mosin,

Had a similar problem to solve recently:
http://www.a7a10.net/forum/index.php?topic=1114.0

Could not find the tap filters and did not want to have inlines visible, went with stainless braided lines, good luck.

[Mosin]

Very neat job Josh. However I suspect that there is probably quite a bit of crap yet to come out of my tank, so I think that for the time being at least I am going to opt for funcionality over beauty and just go for some new rubber hose attached at each end with jubilee clips and with a glass inline filters on each side as these will be much easier to keep an eye on, and also to clean out at the roadside when the inevitable inevitably happens!

[A10Boy]

Mosin

Sorry if you've already done this, but it might be a good idea to remove the tank and give it an old fashioned clean out. Bung up the tap holes and put half a pint of paraffin or white spirit in there, add a handful of clean stone chippings or old nuts and bolts and give it a good shake for half an hour or so. Then give it a thorough clean out. This will remove any old crud or paint that's in there.

[wardleybob]

hello simon jb restorations do the ferrals and the tool to crimp them on for a few £

[a10 gf]

wardleybob, thanks for the info you're providing, but please be aware you are posting in some very old topics.