Re: 75 horse mariner acceleration question
I am having trouble getting a good hole shot on my Bass Tracker. When I adjust my motor to idle at the correct rpms my motor shuts off or hesitates pretty bad when I put it in gear. If I can get it up to about 1700 rpms+ it will run like crazy. I feel like it has to be a simple adjustment but I'm not sure what. I know somebody out there can help. Thanks.
You can look me up in this Forum as I just went through a frightful experience messing with my throttle linkage and tweaking my carbs. I spelled it all out. I have the big brother to that engine (90). Getting the carbs set right is tedious and very small changes in the position of the set screws can have tremendous effects on your engine's performance.
I suggest you get a manual and might do as I did go online and for $38 you get an immediate 3 year membership to the site and can download info for your particular engine and cousins...like the 3 and 4 cyl loopers for a given set of years is all the manual covers....so you get a lot of info and instructions. They sell those manuals on this site cheaper, but I didn't want to wait for shipment.
Meanwhile go look up my recent posts, on this Merc-Mariner forum (that I started), dating back about 10 days from today and you can read about the pegging the tach which stops at 7k, not being able to stop the engine as it was running on it's own pre ignition down to the final post yesterday. The knowledgeable guys on here helped me a lot especially in informing me how critical the adjustments are and how you do a little, wait for things to stabilize and do a little more.
One thing I learned from the experience is that the idle is set by engine timing...so the little "idle adjust" screw just advances/retards timing to change the rpm's. My manual says it should be set to 5 degr BTDC which I did then got on my carbs and very slowly and carefully set them up. Since I have not had it on the water as yet, on muffs I was satisfied with 1000 to 1100 for idle if F (as my service man said) and I am hoping it will drop to the specified 675 when I get it in the water (prop loaded), in F gear, idling.....otherwise I will have to pop the cowl and lie down on the aft deck and play tweak-test, tweak-test...etc. till I get it right and hope that I don't fall overboard.
Good luck,
Mark
