1990 2.4l 200 with wmv18s idle help

[Partonjoshua]

Recently bought a rebuilt 1990 mariner 200, seems to run fine up top but cannot seem to get the idle right. It came with wmv18s which i know are from a newer 2.5l. Issue is in order to get it to idle decently i have to have the mixture screws a half turn out and idle timing set around 8* btdc. At this setting it seems to idle ok, but it starts loading up and has a bog on acceleration i believe is due to being set too rich. If i lean out the mixture screws the bog goes away and it jumps on plane good but does not like to idle in gear. Anybody else try wmv18s on a 2.4l have any suggestions on how to get this thing set up? It starts great everytime, just a tap of the key. Compression is between 119 and 125, checked all bleed lines and check valves, has spark on all 6, new bulb and filters. Not sure how to get this thing right. Thanks

 

[Dukedog]

your motor is a "piston port" 2.4.. those were designed for a "behind tha liner" 2.5 motor ya may hafta do some experimentin' with idle jettin' size ta get it done.. jus comes with tha territory when ya change stuff.. I would monitor tha big end also.. checkin' plugs and piston tops....

jan.. keep it level or tad positive with trim when at idle.. more so for long idle periods.

 

[Partonjoshua]

Ok thanks, gonna start by going up on the idles 2 sizes. I also pulled off the top carb and noticed there are two openings, which i am guesing is the idle circuits on the back of the carbs. The reed plate that i have is flat right there which is blocking those openings. When i look at a picture of a 2.5l reed plate that came with wmv carbs on that portion of the plate there are reliefs cut in them. So on a huntch i ordered the newer style reed plate along with gaskets and ccms reeds while im in there, not sure if its an issue or not, just thought it was strange the part numbers for the 2.4 plate and the 2.5 plate were different and those reliefs were the only difference i could see. What do you think?

 

[Dukedog]

yeah, your on tha right track by gettin' tha right reed plate and gaskets.. wmv's/reed plate, gaskets are slightly different than wmh and wh.... you might see a difference in tha idle without tha jet change.. ya still gonna hafta fool with idle timin' to more than likely......

 

[Partonjoshua]

I will get these put on and post the results, cant find much info on wmvs on a 2.4 so maybe it will help somebody else in the future. Thanks

 

[Partonjoshua]

Quick update, put on right reed plate and ccms reeds, idles much better and the mixture screws actually seem to do something now. Still not quite right, seemed like it was still too rich at idle, but after studying the fuel flow diagrams i realized i have been turning the mixture screws the wrong way. Thought they were air screws and counter clockwise was leaner, but looks like they are fuel screws and clockwise is actually leaner. I believe i am going to still have to go up a couple sizes on the idles, but i am slowly getting it dialed in. Ran the hell out of it today and was pretty happy, but can still use a little less fuel on the idle. But just a heads up for anyone wanting to run wmvs on a 2.4, make sure you have the right reed plate or at least dremel out the idle circuits on the old plate otherwise the idle passages are blocked and it makes it a real pita to get the idle right. Hopefully this benifits someone.