engine building or racing guys please help

[gofastcrazy]

so i had to redo the topend on my 951 went with 1mm over while i was in there i rejetted the carbs with bill's at watercraft magic kit and filters. decided to rebuild the pump,well when i pulled it out the bearing housend was jacked up so bad that i had to buy a new pump housing. so while i was in ther i dcided to got with the solas 15/20....to day was the first water test for the prop and i am only turning 6400 rpms. so my question is do really have to deck the head to get the comp. up so it will pull this prop?

 

[col84]

Everything I've seen says to either have your head cut or go to an aftermarket head before the 15/20.Great choice of prop but got to get compression up.BTW might want to atleast throw in a set of rings when doing the head.

 

[gofastcrazy]

thats what i am thinking on buying a head.... when i say i just redone the topend i mean i have not even got a tank of gas through the new topend job.who's head should i use?

 

[col84]

Miller heads are the best I've seen.You can get them from watercraftmagic.

 

[jwick86]

Before you go cutting the head or buying a new one, did you verify that your rave valves are opening? If not you will lose that RPM. And your only off about 500 RPM. Does the prop spin free in the new housing? If not the bearings are not aligned properly and your loosing RPM there. Are your carbs tuned right with Bill's jets? I have his kit and it rips on top. A little shaky still on the bottom end but rips on top. Check things before you but a new head or cut yours. You get into risking reliability on these 951 motors that can blow up easily as it is.

 

[gofastcrazy]

ok so i put her on the hose today just to see if it was the motor or the prop. she runs great on the hose, it will run up to the rev. all of this with no studder or deto. the next test is to replace the stock prop and water test it.

i called harry at groupk told him what was going on. he said that sometimes they get props in and they are a little off. so he told me to send it back and they will tweak it..... so here goes another week of ride it once and wait on parts fro two weeks....

 

[jwick86]

Did you check anything I recommended above? Out of the water, the motor will rev up no prob with no load on the prop. If it is rave valves, the motor will rev fine out of the water because nothing is loading up the prop.

Mine revs perfect on the trailer, in the water, it stalls when I punch it from an idle, and only an idle I can't tune out yet.

Did you ever run the ski after all the work WITHOUT the new prop? If you did, what was the RPM. Did you try asking Bill what he thinks it may be? He is extremely wise and has plenty of knowledge to get you in the right direction too.

 

[gofastcrazy]

the raves are same as they were with the stock prop.....

yes it was tested with the new topend and the stock prop and it turned 7100

bill told me to call harry so i did

 

[gofastcrazy]

fixed it it was the vacume line going to the rave valve sylinode ( it was unpluged)