Front exhaust loads up the pipe?

[Matt_E]

I took the Superjet out for the first time this year today. I ran the same jetting that I ran successfully for about one hour last year. I know it to be a bit rich.
The ski ran horrible - it would load up and take 3 seconds or so to clear up and load up immediately again after letting off the throttle.

Only mods I made since last year:
Additional Porting
dropped compression from 190 to 180
Reversed carbs (Riva manifold)
Installed front exhaust.


I didn't think nothing of the front exhaust, but when I pulled the pipe off today I found at least a quart or two of water in the chamber.
That got me thinking...is it possible that extra water coming in from the exhaust loads up the engine (which is already running rich)?
Is anyone else with Front exhausts having this problem?

 

[T-bone]

my front(i assume its dual) exhaust did seem to change anything in the running dept.

 

[Freestyleriverrat]

The front exhaust should not do anything to performance b/c the main restrictor is the water box and not necessarily the outlet. The one thing a front exhaust can do is pull in more water when you do a fountain b/c when the exhaust is going out the rear it is achually pulling water in from the front outlet. I think your problem is the porting. The exhaust, reversing the carbs and -10lbs compression should not effect the performance like you describe. Maybe to much exhaust porting......assuming the jetting is correct? How does it idle?

 

[SuperJETT]

Additional Porting
dropped compression from 190 to 180

I'd say that combination is your problem. More porting plus less compression will affect your airflow.

 

[Matt_E]

I agree. The jetting was rich to begin with.
To rehash:

It is at 125 pilots, 122.5 mains, 24psi popoff.

Paul recommended 117.5 pilots and 110 mains as starting point.
I should get those Monday. I'll see how it goes.

 

[Waste Land]

No problems here with front

 

[D-Roc]

aren't you running a different timing curve now since last season on your msd? i don't know if that has anything to do with it but maybe you got a switch wrong.
did you use this?
http://www.msdignition.com/cgi-bin/timingretard.pl?html_link=calculator

 

[Matt_E]

I've thought of that. I checked and doublechecked the settings before I took the ski out.

But, if the jetting doesn't fix it, I'll look at it again. I don't feel it was a timing problem. The engine ran great without a load, but really bad under load. In my experience, that's indicative of carb trouble. Timing/ignition issues should be evident regardless of whether a load is present or not.