Rochester 4MV jets!

[Loa]

Hey!<br /><br />When i opened up choke in carburator i saw that it came more fule from one side. What can be wrong? Can i easily change the jets myself if i got some mechanic skills?<br /><br />Second, choke plate thingy!! does that one has 2 be fully open when engine is warm? As i had to open it a little when warm to look into carburator when running.<br /><br />And... the big plates, when do they open?<br /><br />Sorry for my english <br /><br />Best regards<br /><br />Magnus

 

[Buttanic]

Re: Rochester 4MV jets!

Sounds like the carb needs a rebuild. The reason one side was more than the other is it is partly plugged or the rubber piston on the accelorator pump is bad and yes the choke plate should be fully open when warm. The big secondary plates open by vacuum as the engine needs more gas. Get a rebuild kit and some laquer thinner. Disassemble and soak all the metal parts in laquer thinner. Don't put rubber or plastic parts in the laquer thinner. After soaking it for about 30 minutes blow through all the holes with compressed air and reassemble it. The rebuild kit should come with instructions.

 

[Loa]

Re: Rochester 4MV jets!

ok, but sad thing is that the carburator been rebuilt by mech guy. And i havent been driving over 10H maximum since it.<br /><br />Can this problem i have steal me like 4-5knots at top speed? Cause thats what ive lost since renovation and ive bought new plugs coil etc and timing at8 so that shouldent be ne problem.<br /><br />Ive gone thru whole engine soon it order to find those lost knots.. im my point of view, if i aint got em, somethings wrong.<br /><br />Must add that engine is rebuilt 2001, prop is fine and boat bottom slick

 

[Bondo]

Re: Rochester 4MV jets!

Rebuilding a Rochester is a 50/50 shot At Best.........<br />Choke plates Should be Fully Open, when Warm.......<br />The Secondaries Open at WOT.........<br />I'm Guessing you need a New Carb.......<br /><br />Even with a New Carb(or rebuild), it needs to be Tuned to the motor..............

 

[Loa]

Re: Rochester 4MV jets!

il try re-rebuild it again by myself this time.