Looking for suggestions...

[Cliff]

I've recently bought an MT500, the seller said there was a knack to starting and showed me what he does, although he couldn't get it running. I do believe it was running OK at some point before we bought it.
Have now got it home, tried a number of 'recommended starting methods' and haven't had it firing once.
We've tried with choke, without, a bit of throttle, none at all, pumped with decompression in case it's flooded.
Checked the spark by taking the plug out and holding against the cylinder head, lovely and bright.
Tried deliberately flooding it and sniffing the exhaust, couldn't smell much petrol, so checked petrol flow by taking the pipe off the tank, all good.
Topped the tank up from nearly empty to nearly full with fresh petrol.
Tonight I took the carb off (that's fun, isn't it?), dismantled, checked and cleaned, remantled (I'm sure that's a word) and tried again, nothing at all.
We also tried bump starting in 3rd, then 4th, the engine turned over loads of times but didn't fire once.
Any suggestions on what to look at next?

[Wirralman]

You mentioned a spark but is it at the right time ? Check your cambelt setting.

The original carb was an Amal, fitted for political rather than performance reasons Is it set up correctly, right jets, mixture setting ? Many have replaced the Amal with a Dellorto.

Have you checked the valve setting ?

The best solution if you can't sort it is to take your bike to Sportax, THE MT engine specialist- that would incur cost but you'd end up with a bike that runs

[ZIP TIE]

What’s your rough location?
Someone local may be able to have a look for you.

[lardmarc]

Stator assemblies have been known to break down showing a good spark outside of the engine but failing under compression.

Don't take my word for it.

[Minter]

I've recently bought an MT500, the seller said there was a knack to starting and showed me what he does, although he couldn't get it running. I do believe it was running OK at some point before we bought it.
Have now got it home, tried a number of 'reccomended starting methods' and haven't had it firing once.
We've tried with choke, without, a bit of throttle, none at all, pumped with decompression in case it's flooded.
Checked the spark by taking the plug out and holding against the cylinder head, lovely and bright.
Tried deliberately flooding it and sniffing the exhaust, couldn't smell much petrol, so checked petrol flow by taking the pipe off the tank, all good.
Topped the tank up from nearly empty to nearly full with fresh petrol.
Tonight I took the carb off (that's fun, isn't it?), dismantled, checked and cleaned, remantled (I'm sure that's a word) and tried again, nothing at all.
We also tried bump starting in 3rd, then 4th, the engine turned over loads of times but didn't fire once.
Any suggestions on what to look at next?

If you get no joy Cliff with the suggestions above pop down and see us at Sportax, been working on these motro for 37 years and not had one beat me yet!We get engines and biikes from all over Europe to repair..

[Cliff]

What’s your rough location?
Someone local may be able to have a look for you.

West Cumbria. Look for 'nowhere' on the map, then find the middle of it.

[Cliff]

I've recently bought an MT500, the seller said there was a knack to starting and showed me what he does, although he couldn't get it running. I do believe it was running OK at some point before we bought it.
Have now got it home, tried a number of 'recommended starting methods' and haven't had it firing once.
We've tried with choke, without, a bit of throttle, none at all, pumped with decompression in case it's flooded.
Checked the spark by taking the plug out and holding against the cylinder head, lovely and bright.
Tried deliberately flooding it and sniffing the exhaust, couldn't smell much petrol, so checked petrol flow by taking the pipe off the tank, all good.
Topped the tank up from nearly empty to nearly full with fresh petrol.
Tonight I took the carb off (that's fun, isn't it?), dismantled, checked and cleaned, remantled (I'm sure that's a word) and tried again, nothing at all.
We also tried bump starting in 3rd, then 4th, the engine turned over loads of times but didn't fire once.
Any suggestions on what to look at next?

If you get no joy Cliff with the suggestions above pop down and see us at Sportax, been working on these motro for 37 years and not had one beat me yet!We get engines and biikes from all over Europe to repair..

Thanks for that, I have a few other things to check on first as you are over 200 miles away.

[Cliff]

Update: On further investigation I've found that the nylon insert in the carb tube that enures the plunger is oriented correctly is worn away completely, so there is nothing to stop the plunger from rotating in the barrel. I do have the parts list, but this item is not listed unless it's part of the carb casting assy., so it looks like I can either;
1. Make one out of yogurt cups and sticky backed plastic Blue Peter style, or
2. Buy a new carb as the Amal ones are rubbish anyway.
I think I'll look into option 2.

[bigfatcat]

Mine's got the dellorto and it has run perfectly for the last 12 years. Initially i had a problem with its float leaking/sinking but that's all. I also had an original inlet hose (between carb and engine) fail/crack a couple of times but caused by tightening the jubilees too much, now they ar we just lightly nipped up and the hose has been fine since. Get it set up right and it's a very reliable machine. Have fun.

[bigfatcat]

oh yeah apart from a cam belt snapped a couple of times but easy roadside fix, I always carry a spare, and since replacing the top and bottom pulleys here and tension bearings about 7 years (10000km) ago it's been fine.