So where do I look first?

A

AndyB_11

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Location
Bedford
I've fired up the maybe a Monty this afternoon and after initially running unevenly on the RH cylinder it improved a bit but refuses to run unless the choke is on. I'd got other things to do so it's locked away again now but I've earmarked a few hours for it tomorrow and obviously the carbs will be coming off but has anyone got a suggestion regarding where to start looking?

They've been cleaned in an ultrasonic tank and I've replaced all the seals that come with the carb service kits so most angles have been covered but the only thing I didn't do was check the float heights. That'll be done tomorrow but I don't want to waste my time putting them back on the bike after checking and correcting them if they're wrong if there's something else I should be looking for.

I've got a suspicion that the pump isn't throwing fuel into the RH cylinder properly so any advice on potential problems there will be welcomed. The pistons move freely and the rubber diaphragms looked ok but I've never messed with this type of carb before so it's all a learning curve. If It's still playing up after I've had a look I'll be changing parts from one carb to the other one at a time to try and isolate whatever it is causing problems but that's going to take a fair bit of time and may have to wait for Xmas day when the mother in law is here and I want to be out of the house.

I'm also fully aware that whenever you think it's a fuelling problem it's ignition and whenever you suspect ignition it's fuelling  :'(

 
You seem to have covered most probably faults. See how far out the air screw is on the running pot and match it on the duff pot. Make sure the slides are lifting together if you have had them apart. I once had a guy come round with a Darmah running fine on tickover and on one pot when you reved it after he rebuilt the carbs and i found he had not conected up one of the throttle cables properly so only one slide was lifting.  :D
 
Should still run /tickover even if the accelerater jet isn't working.
If it runs on choke then it indicates fuelling problem.
Make sure the mixture skrews are turned out (counterclockwise) by at least 2.5 turns to start off with.
If it still only runs on choke then you have a blockage.Clean and blow through with compressed air.
The choke lever operates both left and right hand carb chokes.


Andy
 
Well being an impatient sort I adjourned to the man cave again for further investigation.

If I'd removed the airscrews I'd have found that one was screwed right in and didn't have a spring behind it. It's now got a spring out of a pen stopping it from vibrating loose and after a few minutes of running like a dog it now idles at 1500rpm with no choke. All good so far....

Now I bought this bike at an auction with the view that it might be totally knackered or it might be a good buy so I didn't see it running and when I started it at home it didn't run well so I just threw it in the workshop and started messing about with it. Most things seem ok and running it for a while has cleared a few things up but also opened a few issues to be resolved.

The tacho drive leaked but in the absence of the correct sized copper washer a bit of silicon grease has sorted that. There was a bit of oil on the engine because the cam cover gasket was leaking and that's burning off filling the workshop with smoke but that'll clear.

It looks as if it's got a bit of a weep from the cylinder head gasket by the bolt in front the cam chain tunnel. That's not insurmountable and can possibly be tightened and the leak miraculously stopped. It also appears to be leaking a bit from the crankcase joint right by the front engine mount but there's a screwdriver mark there from someone previously splitting the cases so there may be damage on the joint faces that wasn't put right when it was rebuilt.

What I'm not happy about is that there's condensation coming from the engine breather and unless I'm missing something the usual cause of that is the rings being shot. This is confusing me a bit because when I did a compression check the figure only changed by a couple of PSI when I shot oil down into the bores and if the rings were shot I'd expect to see a bigger change. Is there a mesh filter in the housing for the breather? I've not looked yet but that might have a load of emulsified oil in it that's now clearing itself.

Ah well, at least I've got things to occupy me over Xmas  :)

I'll tighten everything up in the morning
 
I'd be inclined to drop the oil, check the screen and put in some fresh stuff before running it any more.
If you don't know what oil is in it or how old it is there's not much in your engine you can get for the price of an oil change.

I dare you to ask for an oil recommendation.

I used a monograde mix in mine just to stir the pot.
 
It's had an oil change & the filter cleaned since it was last on the road and I'm not saying what oil it had put in it because it's not worth starting a war over  :)

Yesterday I stripped both carbs again and blew them through with cleaner then an airline and it still runs like a dog until it's a lot warmer than I'd normally want a bike to be before riding off. Once it's good and hot it ticks over really nicely so there's not much more I can do until everything comes back from being sprayed and I road test it.

It'll piss me off big time if the engine needs dropping because I could have done it weeks ago but fucked about doing other things that could have been done while it was out.
 
  Hi Andy -  I'd take it out for a good run when you're ready before worrying about any problems - it may cure itself or you may find more trouble brewing - best to know exactly what you're up against rather than fix one problem only to get another almost immediately. Engine in and out isn't a big deal on a Monty! - Regards - Phil
 
It's amazing what a good run does for clearing crud out of engines, especially if it involves giving the engine a bit of abuse  :LOL:

I keep having to remind myself that this bike stood for years before doing about 20 miles in a week then me buying it. I'm one of those philosophical kind of blokes that believes problems are just sent to try my patience and the feeling of inner well being gained from solving the bastard things can't be purchased on the internet!

If I start to find it too frustrating I'll go and rejet my H2 which has got a new set of expansion chambers waiting to be fitted and after an hour of that I'll think the Laverda is a walk in the park.
 
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