SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: boatsnores on February 21, 2015, 08:10:59 PM
-
Have a carb issue. Last season rippin around in my sanger seemed like it would run great but if I wanted to do a pass from a dig it would bog for a sec then go. 468 bbc high rise dual plane intake its got the good stock oval port heads mystery cam.. marine 750 holley vs's has #25 squirters pump cam looks to be white? Pulled the spring out of the secondary diaphragm housing. The check ball is not in there. And it had a plain spring I threw a yellow spring in it. And buttoned it back up. Anyways question is do you guys think it is a primary side issue like cam or squirter issue or vacuum secondary issue where the secondaries are not opening up right away?? I dont see any black smoke out the stacks.
Sent from my SPH-L710 using SoCal Jet Boats mobile app
-
I would put at least a 35 squirter in it to start with. Most likely that will help, 25 is way to small. But every motor is different. You might need 50cc accelerater pumps.
-
Where is your timing at and at what curve?
GT
-
Gt, Timing is at 36. And like a idiot I totally looked over the curve. I will have to look at it and get back on that..might be a while since the boat is winterized at this point. Yellow jacket, so I though the smaller the number the longer the nozzle sprays? And the bigger the shorter but more fuel? Also what ever we figure out I am going to a tube style nozzle. What pump is in it now prolly a 30?
Sent from my SPH-L710 using SoCal Jet Boats mobile app
-
get a rough idea what my curve should look like? Start to come in at about 1500 rpms? And full by 3 3500? Should I pull the cover and see what cam I have?
Sent from my SPH-L710 using SoCal Jet Boats mobile app
-
Should be all in at 2,500 RPM.
A jet boat engine does not have to pull a load. The engine does not have much to do at anything below about 3,500 RPM, the timing can come in as quick as you want really. A lzy curve will make it mushy, but should not Bog.
GT
-
10-4 so are you leaning towards a carb tuning issue?
Sent from my SPH-L710 using SoCal Jet Boats mobile app
-
Have a carb issue. Last season rippin around in my sanger seemed like it would run great but if I wanted to do a pass from a dig it would bog for a sec then go. 468 bbc high rise dual plane intake its got the good stock oval port heads mystery cam.. marine 750 holley vs's has #25 squirters pump cam looks to be white? Pulled the spring out of the secondary diaphragm housing. The check ball is not in there. And it had a plain spring I threw a yellow spring in it. And buttoned it back up. Anyways question is do you guys think it is a primary side issue like cam or squirter issue or vacuum secondary issue where the secondaries are not opening up right away?? I dont see any black smoke out the stacks.
Sent from my SPH-L710 using SoCal Jet Boats mobile app
Which yellow spring? there are two.... You should be using either the white one or the short yellow one.
Sounds to me like you need a more aggressive pump cam and potentially a wee bit more pump volume. Do you know what power valve you have?
GT
-
Had the stock plain spring i put in the Short yellow spring. I have not pulled the bowl off yet I will tomarra and see what power valve and jets are in it.
Sent from my SPH-L710 using SoCal Jet Boats mobile app
-
I have seen alot of guys that seem to like the pink cam on similar engines.
Sent from my SPH-L710 using SoCal Jet Boats mobile app