isca1987 wrote:I'm normally alright with doing most think myself and I've have a friend who is a marine engineer and both of use can't work it out.
The bike was running fine but now it just won't start
It has a good battery, good spark plugs which have done less than 700km's, carbs are filling with fuel so it should start but I've really run out of idea's, This weekend I'm refitting all the standard parts back on and see if I have any luck.

so it was running before you messed with it.

The only things the bike need to run is the cabrs, coils and ignition box / pickup coils, you dont need a flywheel or generator or reg/rec for it to run so you can disconnect all that stuff.

It sounds fuel plug related.

Have you clened up the plugs? wire brush them and burn the on a hot stove for a few minutes to clean them up, new plugs might help too.

are the carbs and rubbers on properly?

battery fully charged?

full choke no throttle?

I spent along time in the garage last night back tracking and last week when I checked the spark (plug touching top of engine) the spark was good but now a super weak spark on all four plugs? (Would only spark holding the plug about 5 mm away from the engine so it was arking across) the plugs have only done less than 700 km's but anyways I had a brand new spark plug from a different bike and placed it on the to of the engine and it had a great spark? It just seems crazy for all four plug to go at once but I've ordered some new denso iridium power spark plug [IY27] so I'll see what happens with them fitted.

New spark plugs have been fitted and that has helped a bit now the bike will fire but only when spraying carb cleaner into the inlets, so I'm guessing a carb issue now?

There is no mention of carbs being ultasonically cleaned,
Meybe you should get this done and start again.
Plus Float levels are very important,Spend lots of time making sure these are right,Measured in the right way from the right point.

i hd those plugs in my 30, cracking plugs.

is your fuel tap working? vaccum hose not split and connected proply?

plug the vaccum hose and use a dummy tank for now (funnel on the end of the pipe works well..)

if it still doesnt go then re-check all the carb setup, something doesnt sound right

It's got all new fuel and air lines and I am using a dummy tank with the vacuum pipe blocked, I did phone a few company's about ultrasonic cleaning but they all said they could only do inline 4's so give up on that idea but if anyone knows anywhere that does it I'd be interested. Thanks

VACUUM PIPE BLOCKED.Have you modyfied the tap,If you have removed the vacuum pipe you must modify the tap.

I've blocked the vacuum pipe as the fuel tank isn't fitted. I'm using a little dummy tank to size having to take the tank on and off all the time.

Ok,So gravity feed just to test.

yeah thats right. I've had a bit of luck it is running now on 3 cylinders but when you spray carb cleaner into the inlet it runs on all 4 cylinders so I'm guessing it must be a issue with one carb? So this week I'm going to go through them again