Tracker 195 with spitfire x7 19 pitch problems??

[The gman]

Installed a new spitfire on my 4 stroke 115 and thought I had,have a motor problem. The motor runs great trimmed down and trimmed up for speed but would shake like a miss in the motor at midrange. Changed oil and installed new plugs thinking maybe I got a bad plug, and had 10 hours on the motor but changed nothing. Then I read and watched a video in the mercury section and the poster was told it was the prop cavitating at a certain rpm, trim. My 115 is mounted in the second hole with a pad to prop of 4 inches. What’s your thoughts...thank you

[GeauxTide]

Bring to the dealer immediately. I had bought a factory prepped 2011 Lowe Stinger HP and it porpoised at any trim level. It was discovered that the motor was installed in a 1/4" canted starboard position.

[The gman]

My dealer is 2 hours away and other dealers say 2 week wait

[fishon396]

When I put the spitfire X7 on mine it took me awhile to figure out I was over trimming it on a aluminum boat

[The gman]

Took the boat out today and ran my x7 prop, 3 blade 21 pitch prop and the black max 21 pitch that came with the boat. X7 19 ran the fastest but the two stainless shook the worst. I have come to the conclusion it is prop cavitation. Trimming up and down at a certain rpm creates it

[Highcentered]

Is the white prop bore ring still in there good and tight? The tabs on mine wore out and made the ring pop loose and caused some strange performance issues. Cheap part and good to have an extra laying around. Probably not your problem but still something to rule out.

[msupc]

Installed a new spitfire on my 4 stroke 115 and thought I had,have a motor problem. The motor runs great trimmed down and trimmed up for speed but would shake like a miss in the motor at midrange. Changed oil and installed new plugs thinking maybe I got a bad plug, and had 10 hours on the motor but changed nothing. Then I read and watched a video in the mercury section and the poster was told it was the prop cavitating at a certain rpm, trim. My 115 is mounted in the second hole with a pad to prop of 4 inches. What’s your thoughts...thank you

I had a Spitfire X7 on my Tracker 175 TXW, and what you are experiencing is what I dubbed "Prop Chop". It is not the engine, but rather you are trimmed up too high. Either change props (pitch), lower the engine on the transom, or don't trim up so high.

[The gman]

Thank you msupc that is my next step. Every prop I have tried has this prop chop at some point with the motor in the second hole but I have read that the 4 blades work mounted higher. At 4 inch pad to prop lowering the motor will be 4.5 pad to prop and that seems deep doesn’t it

[Great Scott]

On my TV 18 w/a 6" plate w/no low water pickup gearcase,
5.5" was where it had to run, or it wouldnt water and would blowout
in a turn.
I dont think there is a difference in the pad area on the 18 and the 195
Transom height and transom angle maybe different.
I had the top 3 water intake holes plugged to keep it from sucking air.
and had water scoops on the bottom holes. LDS

[The gman]

I will post this here also. Boat came in second hole, moved it to first hole and no more prop chop, didn’t lose any speed either

[Dharr]

Are you able to trim up all the way? My prop does the same at mid range but i can trim through it and run it just fine