Purchased a used 86 Starts Bass Boat with an Evinrude 140 V4. I've been having problems with the hole shot, it will not rev up to speed, it gradually builds speed. Once up on a plane, I can run 42 to 43 mph (GPS). The hole shot just bogs down. Following some of the threads here I took the cover off of the carburetors to check the jets. This is what I found. I am going to bet that this is not correct. It seems that someone put a philips head screw in place of the 16 jet. Am I correct? Is the 16 jet top end or low end?
Looked up the diagram for the carburetor. #19 is the one that was replaced with a screw. There are 4 jets available. Port side and starboard side. What jet do I order? Should they all be the same 16? at least the one I checked, I did not pull the other one.
You need one for each side. 1 #34 and 1 #37 check your intermediates and make sure they are #26. Remove the carb drain plug and check the high speed orifice and make sure they are 61D after checking the orifice size make sure all of them are fully seated in their bowls. Looks like someone was fighting a bogging issue.
Ok I will check the high speed orifice today. Question: You said "check your intermediates and make sure they are #26 " In the diagram I provide from the website, it says that the #19 orifice is the intermediate Jet, thats the one that has the Philips head screw. The #13 orifice is the Idle air bleed jet. Is the diagram labeled wrong? On both carbs that have both jets installed, I have a #16 in the intermediate orifice (Upper position) and a #28 in the Idle air bleed orifice (low position). Also, there is no #34 or #37 jet available on the website.
Yes that is my engine number, Thanks... Two of my carbs do not have any plate numbers? Not sure if thats normal or not. The two upper carbs are 397907 and 397908. They both take a #20 intermediate jet and #28 idle. The carbs currently have #28 idle and #16 intermediate (plus two that are blocked off with the philips head screw), so possibly they have the wrong jets I am going to assume that all four carbs would take the same jets. I am going to order #20 orifice intermediate for all 4 carbs and see how the engine responds on take off. Thoughts?
This weekend I installed 4 #20 jets for the intermediate orifice. I also confirmed that the high speed jet is a 61D on all four carbs. So on all four carbs have #28 idle, #20 intermediate and #61D for high speed. Immediately, (using the garden hose) I noticed a huge improvement in idle. Before the idle screw was bottomed out and the engine was just looping and very low. Sometime it would stall when shifting out of reverse back to neutral when in the water. So I thought this was the fix it needed. Took the boat to the lake. Made my finally idle adjustments in the water and was real encouraged, because the idle screw was actually backed out and had plenty of room for adjustment. The idle was a lot smoother. Making my way out of the no wake zone the engine felt solid, smooth and ready to go. As soon as I accelerated, it fell right on its face and stalled out. I could not get the boat to plan out under normal throttle. I had to very slowly accelerate the engine. Once up and running it was not running as fast as it was before with the block off intermediate orifice. 5 minutes on plan the engine lost power went dead in the water (never happened before). I wish I had presence of mind to check the fuel bulb, but did not. It started back up and I returned to the dock.
Heres what I know:
With two carbs blocked off at the intermediate orifice and two #16 jets in the other two intermediate orifices. The engine
Idles low and like crap / stalls out at idle shifting in and out of reverse or forward.
Will wind up and eventually get up on a plane, but takes a little while (pushing the choke in makes it worst)
Runs easily 43 mph (gps) at 5k RPM.
I can run the boat like this all day and enjoy being out of the water, just have to be patient when getting up on a plane, but seems to use a lot of gas.
With all four carbs setup up per factory specs, #28 / #20 / #61D
Engine Idles great,
Stalls out immediately on acceleration (using the choke may have made a slight difference, couldn't really tell).
Top end speed seems reduced.
The spark plugs do not have the ground electrode. Coil packs appear original. Power pack appears original. Rectifier / regulator I just changed to get it to start charging again.
Fuel flows fairly easily from the bulb. Bulb seems to always be full, every time I have checked.
Someone was trying to work out the bogging issue, but did a poor patch job. With the information I have given, where should I start?
I really could use some help, so if you got any suggestions please let me know.
1987 Evinrude
E140TLCUA
Two carbs are 397907 and 397908
Try running it with one screw in and the 3 mids in and see what happens. Whoever decided to try this setup is trying to compensate for another issue with the motor. These can be very hard to find.
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