H2X questions
 

This has probably been asked/answered before..........
1. How can I tell if I have a mag engine (1998) h2x 7.4 mpi ?
2. How can I tell if my prop has been labbed ( Mirage 23p) ?

Ed

Mags say 454 mag mpi. 385 HP.. there is a 7.4 LX that has same intake @330 HP.

Then the 7.4 that looks a lil different at 310 HP. Mags rev to 5k (suggested top on range at WOT.) MP I and lx are 4600.

See one my 98 454 mags attached.

Labbed?? Can usually tell if has a lil more cup than normal.. Thinner maybe, sharp edges.?? What speeds (GPS ) are you getting and we can probably tell. I had a 25ol with a 23p m+
4k at 47-50 depending on water/heat/load. Topped out at 5100 at 64.7 in 50 degree w/ 2's 2 men and full fuel. Normally 4900 at 63 in summer and normal load/conditions. Non labbed and gps speeds. Given 1.5 drive non labbed should net the same speed at 4k.

Thanks Nailit.
So definitely not a Mag, and I'll have a better look at the prop on the weekend. As far as speed, I ll have to wait until I get a GPS to get an accurate speed.
http://i1256.photobucket.com/albums/...ps0d53a788.jpg

Yep that's the 7.4.. I have heard/read those things last forever unmolested!! If you have a smart phone.. you can get a GPS app. I had my iPhone on my seal trial a few weeks ago and one of the apps I found had Max speed which was cool that I didn't have to hold the phone on the first time I had driven a 33 ft boat with twins.., although, after playing with my GPS speedo it has a tattle tale with Max speed.. :-)

what happened to my pic?

looks like photobucket deleted it or you did from photobucket Nailit is correct about the life of the 7.4 mpi leave it alone and use it i know a guy in MI that has over 1000 hours on his ( nightlife on here )

Mine are carb 365 hp mags not the old 330 or MPI, but do have over 1000 hours on them.

This one has 500 hrs on it, and if the PO took as good care of the motor as he did the boat, I should have no issues for a long time.

Keep an eye on the exhaust manifolds. I purchased the exact boat last year with 300 hours and the motor was shot due to leaking exhaust manifolds. We really love the boat, sometimes we wish it was faster! We get 60 on the GPS everyday of the weak with the same set up you have running 4400 rpm. I have a 21p mirage plus coming this weak and I'll let you know how it goes!

Thanks,
I had it out yesterday, 58 on GPS at 4500 was the best I could do, let me know how that prop works out for you.

Prop should be here today I can't wait to try it out we are right at the same speed. I'd love to see 64mph I may send the 23 out to get worked over if the 21 doesn't do the trick

Larry

Ram the 21p mirage plus today full of fuel 56 on GPS at 4600 lots of cavitation when trimming up came out of the hole better but I'd say I'm thinking the best route for me is to lab the 23 mirage plus

Larry

Yup, sounds like the most popular choice for our set up, I'll have to see if I can find a reputable local shop before I spending $$$$ on shipping to and from US.

Spoke to BBlades today and sounds like we're going to try 25p labbed, I'll keep you posted once I receive it.

Let me know how it works! What was the turn around time for a labbed prop? I'm anxious to find something that works a little better