Hi guys, i recently bought a deltek deckson mini bike with a 1977 3.5hp briggs with the model number 80302. When i first got the bike i put some gas in it and by pulling it had no compression so i tore the engine down and put new rings, gasket, spark plug and cleaned the head and valves ect. but i put it back together and put some petrol in it and it fired up but didnt start. So about 3 hours later of tampering with the carby and cleaning it no luck. The problem is it will fire up and start very rarely but i think the timeing is out or something i took the valves out and timed it correcley but no luck.
Help on a 3.5hp briggs.
- Thread starter DeltekMania
- Start date
- Tags 3.5hp briggs.
Correct me if I am wrong, but isnt the valve clearence 5-7 thousandths for the intake and 9 to 11 thousandths for the exhaust???
Also look to see if the head of the valveis bent. you can do this by taking the valve out and sticking the stem in a drill and spin it. if there is any out of roundness it wont be making a good seal on the seat. Also if you need to open the valve lash, you can take the end of the stem to a bench grinder but be carfull not to take too much off and make sure it is a good flat grind too.
Also look to see if the head of the valveis bent. you can do this by taking the valve out and sticking the stem in a drill and spin it. if there is any out of roundness it wont be making a good seal on the seat. Also if you need to open the valve lash, you can take the end of the stem to a bench grinder but be carfull not to take too much off and make sure it is a good flat grind too.