Port engine backfire

[skyscraper88]

It is truly a sad day. The TaTa's have been offically put to bed for the winter.:smt089 As I went to over to pick her up, the mechanic told me that the port engine has a misfire in it. He rambled thru a few different senieros about what could be going on. Everything from bad plugs/wires all the way to bad valves to water bypassing the risers. It has backfired a few times while trying to get up on plane, but once the RPM's come up she runs just fine. Does anyone have any suggestions on what it might be? would a backfire be caused by a bad riser, of bad valve seat? timing seems to be right where is should be. planned on replacing the plugs and wires next spring. Are there any tell tale signs on what to look for if the riser might be bad?? :smt100

 

[hottoddie]

Are the motors fresh or raw water cooled? How many hours? Are they the original motors? When was last complete tune up? If water is getting into the cylinders thru the exhaust and you put it to sleep for the winter the moisture could cause a problem. A compression check and spark plug exam is in order. If all that checks then a tune up may cure it or you could a vacuum leak, something as simple as the carburetor hold down bolts being loose or an intake manifold gasket.

 

[skyscraper88]

Are the motors fresh or raw water cooled? How many hours? Are they the original motors? When was last complete tune up? If water is getting into the cylinders thru the exhaust and you put it to sleep for the winter the moisture could cause a problem. A compression check and spark plug exam is in order. If all that checks then a tune up may cure it or you could a vacuum leak, something as simple as the carburetor hold down bolts being loose or an intake manifold gasket.

Engines are fresh water cooled. they both have a little over 1200 hours on them. from my understanding they are the orgional engines and out drives. i planned on doing plugs and wires in the spring. mechanic said that all the fluids looked good and clean. engine also has been fogged for winter storage. not sure when the last tune up was done. i did change the cap, rotor, and star wheel in the distributer at the start of this season. timing was off in this engine also. i set it back to 8deg btdc. thanks for the help