Thread: Speed loss @ WOT
03-17-2013, 03:38 PM #1
- Join Date
- Sep 2012
Speed loss @ WOT
Bizzare problem, but ive noticed a few times now that when the water is completely flat and I get to WOT, my ski seems to loose speed. Ive compared it with my friends GPR with almost identical mods, we hit max revs and were side by side then after about 2 seconds, he starts pulling away from me by about a ski every 150 metres or so...
Using the speedo as a guide, it says im doing 120kph, then all of a sudden it drops to about 111kph. I know its not accurate, but just using this as a guide.
The ski seems to run fine and I cant see or hear any issues. Im assuming that maybe my revs are too high and maybe im out of the power-band? That is my initial feeling. I haven't checked that yet, ive just ordered a tiny tach to check that. Currently using a 14/20 dynafly.
Worx intake grate
Riva ride plate
Riva trim tabs
Free flow exhaust
V force reeds
Riva efi controler
Pump seal kit
03-17-2013, 04:58 PM #2
You're gonna have to get a proper tachometer first and foremost. This will be key for you now and in the future, it is a worthy investment. Now about your problem, how many hours on the engine? Have you done a compression check on the cylinders? Do you have a good compression gauge? if not get one, it is another invaluable tool for the future. Have you changed fuel octane lately? How are the power valves operating? Do they cycle properly? Spark plugs...how old are they? You will have to provide more info in order for help to cyber-tune this ski. So, you've just now started...get us the useful information bro. It may need a carb re-build of the carbs are starving for fuel at WOT..there is a myriad of choices for diagnosis..you're gonna have to provide more.
03-17-2013, 05:48 PM #3
What year & model GP do you have ? How many hours on current engine ? I have the same mods & have yet to experience you issues. Please post your findings & results as you takle this problem ... I am very interested.
Thanks, stay on & post your data.
03-17-2013, 06:10 PM #4
- Join Date
- Aug 2011
03-17-2013, 08:18 PM #5
03-18-2013, 11:49 AM #6
Yeah the reserve line extends itself and has caused lots of lean seizures at wot. It bumps up against the flapper. Are you running on reserve?
03-18-2013, 05:48 PM #7
- Join Date
- Sep 2012
Ok to answer some of your questions... Ive ordered the Tachometer so should have that this weekend.
The ski is a 2006 GP1300r.
The engine has about 35-40hrs on it since it had a full rebuild. The jet pump has about 25hrs on it since it was replaced due to sucking up a rock.
I did a compression test on it this afternoon and got 135 / 135 / 130.
The spark plugs would be about 10-15hrs old as I replaced them at the start of this season (AUS).
The ski since ive owned it has always run 98octane (which is 93octane in the US iirc)
How do i check to see if how the power valves operating? And I would have no idea how to check "reserve line extends itself and has caused lots of lean seizures at wot. It bumps up against the flapper. Are you running on reserve? "
I did a search but maybe I was typing in the wrong things because I couldn't find the info i needed.
03-18-2013, 06:27 PM #8
03-20-2013, 01:27 PM #9
If you can't find it using the search button just use google. Most of the time the first searches are always links the the hulk.
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By c6rvette in forum 4-Tec PerformanceReplies: 6Last Post: 06-06-2008, 09:24 AM
By kepneriphone in forum Polaris Open DiscussionReplies: 17Last Post: 09-19-2007, 12:10 AM
By BlaZinMJ in forum 4-Tec PerformanceReplies: 21Last Post: 05-27-2007, 10:38 AM
By NateGP1300R in forum Yamaha PWC Performance (2-stroke)Replies: 18Last Post: 07-23-2006, 12:53 PM
By Alaska05RXT in forum 4-Tec PerformanceReplies: 7Last Post: 05-08-2006, 08:46 AM