NEED 250xs help

[dakotahunter12]

I have an 06' 250xs, when I start out from idle and slowly give it throttle it stays at the same rpms for a few seconds as I increase throttle and then all of a sudden takes off. I also noticed that when I go from a dead stand still and drop the hammer on it, it has a big delay before it takes off. it seems to run fine and idles nice. what could be causing this?

[canadabullet]

If your prop has a large diameter and lots of cupping it will often not ventilate as quickly through the vent holes , like a smaller dia prop due to the outer edges still being in unaerated water. This gives a momentary bog feeling when mashing it because of the added bite.... Just depress the throttle a little bit at first to allow the aerated water to give some slip until you see the revs climb on the tach ( you will feel it as well ) and then mash it... Usually props that exhibit the slight bog on mashing the throttle have the benefit of not blowing out on breakover... In my testing the Hydromotive Quad 4X props behaved like that...


Modified by canadablazer at 6:18 PM 6/6/2010

[dakotahunter12]

blazer
when props cause it to bog can't you feel that in the motor or is that different with a venting issue? this doesn't feel like I'm bogged down while trying to get on plane, it feels like the motor is not responding to the throttle and then all of a sudden it just goes. Maybe it is prop slip but it does it with both my props, 23 tempest factory, and a bravo 1 Croxtified with dual vent holes. by the way this is on a heavy deep v ranger 620 multi species.

[canadabullet]

You might have an engine issue then... Try fresh sparkplugs...

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by canadablazer &raquo;</td></tr><tr><td class="quote">You might have an engine issue then... Try fresh sparkplugs... </td></tr></table>

+1

I'd also recommend verifying that the engine is coming up to operating temperature (thermostats aren't hung open with debris).... and inspect the belt/tensioner under the flywheel cover for signs of wear, stretched belt, etc.

Another item you might want to look at (and take to heart):

http://www.bbcboards.net/zerot...first

[dakotahunter12]

Don what is the operating temp on this motor?

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by dakotahunter12 &raquo;</td></tr><tr><td class="quote">Don what is the operating temp on this motor?</td></tr></table>

Serial number required to identify thermostats for certain.

You should be reaching a MINIMUM of 120 degrees at both thermostat covers, with the engine running AT IDLE. If you have Smartcraft, you can monitor temp at idle for a minimum of 120 degrees.

[Ranger Z522]

mine has done that from about 3 months new. to the present...it's a 09 motor and I started using/running it since March of '09...it doesn't come off idle any where from 1 to 4 seconds when I drop the hammer,just stays idling and then blam WOT...via merc techs,the techs at Ted's have put the "test" pcm (or ecm,forget the name,but it has "TEST" stamped on it) and it was ok for about 3 times out and then back to 3-4 seconds hesitations...merc had me run a pre mix of opti oil extra in my gas tank(25 gal of it) late last year and no change... ..last week they change injectors and it had a 1 plus second hesitation and slight stumbling/bumbling for about 2 plus seconds(new prob) and I just took it to Ted's for another pcm/ecm change out this morning ...will go test it after they change it out and see what that does...

[dakotahunter12]

I talked with my local merc dealer and even though they have not dealt with the racing xs much they have sold a lot of the pro xs. They told me this was common with the merc dfi as it has to build up pressure. Is this accurate? I had a Yamaha HPDI before this and it wasn't this way.

[EuropeanAM]

Although the DFI does have to "build" air pressure... air pressure SHOULD be present simply by virtue of the fact that the engine is running.

There are numerous items that should be checked when acceleration problems exist- STARTING WITH carbon buildup, injector clealiness, air and fuel pressure, AIR PRESSURE SYSTEM LEAK TEST, spark plugs, PROP PVS HOLES ADEQUATE TO SPOOL RPM'S, Belt condition and tension, and a visual inspection inside the intake plenum for any "loose items" that don't belong there (such as tie wraps, leaves, or yellow plastic caps).

It can be time consuming.... but it's rewarding when the end result is the "blistering holeshot" that the engine SHOULD exibit.