RPM and hole shot problems 200 2.4L Mariner

[oceanboy78]

Hi guys, I am hoping somebody can help me here because I really feel like I have been ripped off.<br /><br />I have a 200 mariner 2.4L on a 16 foot boat running a lazer 23pitch ss prop. used to rev comfortably at 6000rpm.<br /><br />For 6 years I have had a hole shot performance problem and I tried to get it fixed recently. It bogs down and dosn't want to plane.<br /><br />The mechanic replaced my stator, he said it was no good, didn't make the motor run any different. he then rebuilt my carbs and changed the low and medium jets.<br /><br />He assured me it would go like a rocket (although he never water tested it), I put it in. It stalls when you accelerate and decelerate<br />and still bogs down. I have also lost 700rpm top end. instead of running at 6k it now tops out at 5300. Naturally I took it back to him, 3 weeks later he hasn't done anything. I have already paid for it so I have to wait it out.<br /><br />Compression is really good 140psi all cylinders<br />powerpack and regulator rectifier was also replaced 6 months ago, I believe the only thing I haven't replaced is the coils.<br /><br />Does anyone have any suggestions why this big baby wont run.<br /><br />Many thanks

 

[andy6374]

Re: RPM and hole shot problems 200 2.4L Mariner

What year is the motor?<br /><br />Did he put different size jets in?<br /><br />How's your hole shot after you've already been at WOT for a bit, that is after you come back down from WOT.

 

[oceanboy78]

Re: RPM and hole shot problems 200 2.4L Mariner

It is a 1990 model 2.4L <br /><br />yes he changed the jets, he changed the low and mid but did not change the top jets, he made the mid richer and the low leaner. he also did the fuel pump and other hoses<br /><br />After being up on the plane WOT when i back it off it sometimes stalls, the hole shot performance does not improve after being on the plane at high RPM, it also stalls sometimes when I accellerate from the hole. <br /><br />the mechanic was very surprised that it ran worse after he did the work on the carbs and I dont know where my 700rpm has gone from top end.

 

[andy6374]

Re: RPM and hole shot problems 200 2.4L Mariner

Toss the midrange jets, no good! They are designed to give better fuel economy at the midrange, but can end up leaning your engine out.<br /><br />As for the idle jets, did he give you larger orfice (leaner) or smaller orfice (richer) jets? Rich idle jets can kill your hole shot, if this is the case this can usually be taken care by giving a quick run at WOT or given some higher throttle in neutral before take off.<br /><br />What size jets (all) are you running?<br /><br />Are the carbs in sync? Do the throttle plates fully open at max throttle? Do they fully close at idle?<br /><br />It doesn't have to be a fuel issue, but lets rule it out if it isn't.

 

[oceanboy78]

Re: RPM and hole shot problems 200 2.4L Mariner

Thanks for the info andy<br />I will get all the details of the jetting (sizes) and check the things you mentioned and let you know what I find<br /><br />talk soon

 

[oceanboy78]

Re: RPM and hole shot problems 200 2.4L Mariner

Thanks for the info andy<br />I will get all the details of the jetting (sizes) and check the things you mentioned and let you know what I find<br /><br />talk soon

 

[andy6374]

Re: RPM and hole shot problems 200 2.4L Mariner

The reason I asked the jet sizes is because unless you change altitude or have the engine rebuilt you shouldn't change the jet sizes. Proper/Fuel to air ratio is critical. With every rebuild on a V6 you should increase the main jet size by .002", not so sure about the idle jets though.<br /><br />But definitely trash the vent (midrange) jets.

 

[oceanboy78]

Re: RPM and hole shot problems 200 2.4L Mariner

Hi Andy, I haven't water tested the boat yet but I have got it back ready to try.<br /><br />The mechanic said the timing was only set to 10 degrees and that it was severely retarded.<br /><br />He was very confident that it would fix the problem. I will give it a try this week and let you know how it goes. I dont have the details of the jet sizes but I will get them off the mechanic

 

[paulie0735]

Re: RPM and hole shot problems 200 2.4L Mariner

sounds to me like your 'mechanic' is just guessing with your engine!! Timing is critical on an engine like that and should have been checked before any parts were replaced, have you been ripped off?? absolutely!!