Thread: 96 slt 780 re-build
04-27-2010, 09:39 AM #1
96 slt 780 re-build
i am going to go ahead and rebuild the top end any advice on performance mods i can do without breaking the bank?
04-27-2010, 09:57 AM #2
I got my heads machined down flat to the domes.. that adds a bunch of low end power for relatively cheap, just make sure a decent machinist does it. I also had to mess around wtih head gasket thicknesses to get the compression down to something that wouldn't detonate... so if your not into messing with compression you could safely shave off .020" without boosting it too much. You already have the long pump and the tripple fuel pump.. could have someone port out your cylinders too but you have to make sure who is doing it knows their stuff. There are other mods you can do too but the parts are becomming harder to find. on my SL780 ive got v force 2 reeds and vortec f/a's and hot seat water box.. oh another good easy one is the pro785 CDI you can do a little rewiring and that adds some more punch too. You looking for top speed or acceleration???
04-27-2010, 10:15 AM #3
how much do you have too spend? the mods you can do all depends on what you can spend.. id make sure all the maitnence is takin care of first thenget it running then worry about gettting go fast parts..
04-27-2010, 10:21 AM #4
I personally like to do everything at once but if you do that your asking for everything to cause problems at once too
04-27-2010, 10:26 AM #5
04-27-2010, 12:27 PM #6
Yes it is expensive. There are some elementary methods in one of the tech sections - alexander bell porting ducument. There are some things you can do to get good results without too much effort. Not sure where it is but after reading that I thought about porting my cylinders but knowing my luck I'd slip with the grinder and nick the cylinder wall.
04-27-2010, 12:31 PM #7
04-27-2010, 05:51 PM #8
- Join Date
- Oct 2006
- Cleveland OH
I have to disagree with FL on a couple things.
Just decking your heads to get higher compression is asking for reliability issues.
When my heads were cut for 92 octane fuel, they decked the heads, but also modified the fuel bowl and the squish band to ward off detonation. You can have your stock heads done for around $40 ea.
I'd advise against the Pro 785 CDI on a SLT. The timing is too much for a ski that will be pulling 3 people or a tuber. While I do agree it will add a boost down low, it's going to give you reliability problems if you put alot of stress on the engine.
The 780 came from the factory pretty much built up. Not too much you can do to it without spending ALOT.
What I would suggest is new performance reeds. ($80-350 depending on which you get)
Maybe the high compression heads. ($120ish)
Consider a jetworks valve for a slightly better hole shot. ($40)
Stainless Steel 6 vane jet pump stator for and additional 1-2 MPH ($80-150 used)
And just make sure the ski is in all around good running condition. Impeller in good shape, tolerance to wear ring is tight, pump bearings feel good, etc... Jet pump stator blades are in good shape and not chipped up.
Engine has good compression and turns 6500 RPM.
That's what I suggest.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By H2ONUT in forum Polaris How To & FAQsReplies: 57Last Post: 03-05-2008, 04:29 PM
By moosehead4242 in forum Polaris Open DiscussionReplies: 5Last Post: 08-22-2007, 06:53 PM
By paramuir in forum Polaris Open DiscussionReplies: 7Last Post: 07-15-2007, 05:53 PM
By BBCaprice in forum Polaris Open DiscussionReplies: 13Last Post: 05-14-2007, 10:25 AM
By rbridges in forum Polaris Open DiscussionReplies: 8Last Post: 05-04-2007, 09:10 PM