Hi folks. I recently bought and old Heli 25. On arrival it constantly frosted over and would only runs with a kettle to hand. I removed all the regulator warming hoses and cleaned them out. This solved the frosting issue.then after 5 mins of running it stopped. Restats instantly ran for 5 seconds snd stops again. Did this 20 times and i left it overnight. Next morning fired straight up and ran ticking over for 7 mins and when i pressed the gas pedal it stopped straight away. Instantly started again but will only run at tick over. Any ideas?