Thread: Popping & Impeller ???
07-31-2008, 07:42 AM #1
Popping & Impeller ???
Guys, quick question, rebuilt unported 1200 just broken in was on 27:1 premix for 1st tank now on 32:1 Yamaglue (thats the best I can get and Ive been told they have even run out of that - Mercury Premium Plus next) . Ski pulls strong and revs well but occasionally I hear a "Popping" sound from the exhaust. More so from the shore when someone else is riding. Occasionally on mild acceleration and ,say, 30mph cruise. I feel its a little rich. Engine mods are, Riva heads, Stinger 3 , billet PV's, Wave eaters, stock reeds with stuffers, carbs 125/110/1.5/95, chokes plates and accel pump removed, primer install and gutted stock airbox(ride surf) current impeller is Solas 13/19 (very worn)
If you need any futher info please ask.(No rpms till weekend and dont even ask about top speed until my new prop arrives - its embarassing)
Speaking of impellars which one would you guys choose????
07-31-2008, 10:04 AM #2
08-01-2008, 07:05 AM #3
08-01-2008, 07:26 AM #4
a little poppoing sound is normal on initial acceleration and slow cruise......as long as the ski moves off well....it should be fine....
08-01-2008, 07:32 AM #5
Impelller ? I was thinking 13/20SB or 14/20 or something wierd ?
Will my ski have enought power to spin a 14/20 or is a 13/20 the best of both worlds- it currently has a very worn 13/19 and I need to get a new one bust I also need to get the right one because getting stuff here is expensive and takes ages.
08-01-2008, 05:50 PM #6
.....The 13/19 is a great choice for your setup...it will give you good top end but GREAT low-mid end....the worn one may be able to be cleaned up if its not too badly worn...can you take a couple of pictures of it?
08-01-2008, 06:01 PM #7
Not really sure what to blame the misfire on. What till its got a fresh set of plugs and your running the final premix to see if its still occuring.
08-03-2008, 12:29 PM #8
Duke, funny (well not really) I never thought of the 'popping noise' as a missfire. But yesterday #1 cyl crapped out. Compression and fuel is there but spark looks weak. Also it was the first time out with my pet tach and that was getting some wierd readings. My leads are original at 372 hrs so I guess it's time for new ones although I am sure the guy I bought if from put new coils on it. If a cdi goes down can it only go on one cylinder or would it take out all three.
I know Im gonna need to order parts ,,, I just wanna make sure I get the right ones cause as Ive said before it takes ages to get stuff here.
Boost, ok thanks but what about the 13/20 SB riva - would that not give me same low and mid but with scope for further tuning / or does it not work like that ? I know inpeller could be repaired but not here it would be quicker, easier and cheaper to buy one, and I will know its good . Mine has approx twice as much clearance as it should have witha new w/ring, Best I got yesterday before the above happened was 60.5 mph at 6800rpm
08-05-2008, 09:50 PM #9
...The 13/20 setback will have a much steeper trailing edge...that will require alot of power on top....you may not have the power to pull it...so your revs will be way down compared to the 13/19....the SB(setback) will be ok though...it eliminates a bit of cavitation from your holeshot...assuming your shoe is sealed up in the rear nicely...
....i wouldnt go the 13/20 route until you have significantly more power on tap....
08-06-2008, 10:54 AM #10
How much extra are you thinking ? What extra mods would I need to get there ?
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By jbuhles in forum 2-Stroke PerformanceReplies: 7Last Post: 08-25-2010, 07:49 PM
By Turbo Todd in forum 4-Tec PerformanceReplies: 10Last Post: 11-21-2008, 10:55 AM
By Teflon in forum 4-Tec PerformanceReplies: 3Last Post: 05-09-2005, 06:01 PM
By Jrsrxp in forum 4-Tec PerformanceReplies: 3Last Post: 05-06-2005, 02:01 PM
By shhr in forum 4-Tec PerformanceReplies: 14Last Post: 05-02-2005, 09:31 PM