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Backfiring through Carb after Carb rebuild

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Yo..

That's great!, (carb testing)...As far as gasket, REPLACE IT. Only problem with this being possible conclusion, is that, even though there's a rip, its not ripped at exhaust outing, meaning to me, that its not being effected???

Reread some of the earlier post, try the "have not" possible solutions...(disconnect the red wire from rectifier, clean/replace/bypass the fuel selector..). Start with one first, though...:cheers:
 
timmyboy76 said:
Yo..

That's great!, (carb testing)...As far as gasket, REPLACE IT. Only problem with this being possible conclusion, is that, even though there's a rip, its not ripped at exhaust outing, meaning to me, that its not being effected???

Reread some of the earlier post, try the "have not" possible solutions...(disconnect the red wire from rectifier, clean/replace/bypass the fuel selector..). Start with one first, though...:cheers:
Click to expand...

Timmyboy good to hear from you once again. As far as testing goes I have already cleaned tested fuel selector valve and I Have disconnected the rectifier and I get same effect. Now as far as the exhaust here I would have not known there is a leak there until it started to spray water out the one side where the gasket is torn. I found out in the driveway with the hose connected as I gave it throttle I got more water spraying out. So it looks to be the original gasket right, and maybe sense the last time I rode her when she was working great I remember taking her really hard on the wake's jumping waves! So im thinking maybe this started out as a very small air leak which caused bogging and has now evolved into big airleak enough for water leakage and caused this backfiring. So the Gasket will be here tomorrow I will let you know how it goes and please let me know your opinion.

CHEERS:cheers:
 
Well all its taken over a month for me to find the problem and fix it, I think I did nearly everything that was mentioned to do has been done. I truly really could not fix this terrible problem without out the help of the great people on this thread and forum.

It has been like putting a large puzzle together and a long the way missing some vital pieces..I now know this problem started out as a very small leak on the exhaust manifold gasket area. Which in turn evolved in to a noticeable water leak. So I immediately
ordered a new exhaust manifold gasket from seadoowarehouse and put it in also replaced all the clamps and seals.

Now all I can say now is I can hear a noticeable difference and I no longer get backfiring when the water is flowing. this was the fix!

THANK YOU ALL SO MUCH, my carbone ring broke so thats the last fix then I will be on the aqua once again.

take everyone and keep in touch

:cheers::cheers::cheers::cheers::cheers::cheers::cheers:
 
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Well It was running fine until my Carbone Ring broke and the drive shaft had gotten bent, So I purchased a new drive shaft and and pulled the engine and now I get the same old backfiring, just because I changed the drive shaft out?? If anyone has any experience with a problem like this or suggestions or help are greatly appreciated I have obvious tested many things out if you read previous post.

thank you take care

sincerely

Joey
 
What plugs are you running? And have you tried replacing them yet?

The typical reasons for backfiring are as follows:
Weak spark due to fouled/defective plugs or malfunctioning rev limiter
Ignition timing due to incorrect setting or sheared woodruf key
Rotary valve timing incorrect
Carburetor too lean
Intake leak or crankshaft seal failure
 
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PWCdoc said:
What plugs are you running? And have you tried replacing them yet?

The typical reasons for backfiring are as follows:
Weak spark due to fouled/defective plugs or malfunctioning rev limiter
Ignition timing due to incorrect setting or sheared woodruf key
Rotary valve timing incorrect
Carburetor too lean
Intake leak or crankshaft seal failure
Click to expand...

Okay well the plugs could be fouled ! the rev limiter how do you check that?
How do you check the woodruf key? Rotary valve timing is good, Carburetor are good/set right, Intake leak was fixed for the first round of backfiring but maybe the cause once again but I doubt it, might be crankshaft seal, thanks alot

Joey
 
what up Joey...
Why the heck, you brake the ring for..:rofl:
You mentioned in 11/08, that you needed to replace it then, so..did you have chance to run after the gasket repair, or it just "sounded" better, not backfiring) when on hose?
 
gajipr said:
Okay well the plugs could be fouled ! the rev limiter how do you check that?
How do you check the woodruf key? Rotary valve timing is good, Carburetor are good/set right, Intake leak was fixed for the first round of backfiring but maybe the cause once again but I doubt it, might be crankshaft seal, thanks alot

Joey
Click to expand...

First, just try one thing at a time so you find out what the problem is, or isn't. Then proceed with the next step. So, that being said, change out your plugs and let us know what she does. Make sure you use the correct plugs for your ski.
 
timmyboy76 said:
what up Joey...
Why the heck, you brake the ring for..:rofl:
You mentioned in 11/08, that you needed to replace it then, so..did you have chance to run after the gasket repair, or it just "sounded" better, not backfiring) when on hose?
Click to expand...

Ya I replaced it back then right, and then I found out that my drive shaft got bent as well, probably at the same time the ring had broke! So I had to wait several weeks in order to find a new drive shaft, So once I found a drive shaft like just before Christmas I put it in and I went to take it down to the lake for a test run, but as I always check for leaks there was a big time leak right in front of the carbone ring, (reason) I forgot to put the proper O-ring in place and the rubber piece that goes on the tip of the driveshaft! but even thought it was leaking I took out and it ran perfectly no backfiring perfectly! but of course I had to take out the shaft once again to replace the leak on the drive shaft, so once I got the engine out again, and fixed the leak problem I went to test the engine in the yard and once again it backfired ! !

So to answer your question which I really appreciate, the backfiring once I replaced the gasket really never went away, it only backfired when it was running dry???? but when it had water flowing like when I go to flush it out in the yard it would never backfire, but now its back to the same old thing backfires dry or wet OH! and this stumped me big time I even got a big spark?? from like the top of the engine I could not pinpoint it. Last time I tried it one of the exhaust seals literally pop right off I am guessing from excess pressure.
thanks alot

Joey
 
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Sounds to me like it's hitting the hell out of the rev limiter more than anything else. Just out of curiousity, look into the pump and tell us how much clearance you have on the outside edge of your impeller. Also, when a ski backfires, you will literally see flames in the throat of the carburetor and hear the definitive "bang". Fuel spitting back out of the carb is not unusual and more indicative of a RV timing issue than anything else.

The reason to have the f/a installed is to provide the correct amount of vacuum on the carburetor to get the appropriate amount of fuel.

Also, when did you paint the motor? Or is it a replacement engine?
 
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PWCdoc said:
Sounds to me like it's hitting the hell out of the rev limiter more than anything else. Just out of curiousity, look into the pump and tell us how much clearance you have on the outside edge of your impeller. Also, when a ski backfires, you will literally see flames in the throat of the carburetor and hear the definitive "bang". Fuel spitting back out of the carb is not unusual and more indicative of a RV timing issue than anything else.

The reason to have the f/a installed is to provide the correct amount of vacuum on the carburetor to get the appropriate amount of fuel.

Also, when did you paint the motor? Or is it a replacement engine?
Click to expand...

What do you mean its hitting the rev limiter? How can I tell how much clearance there is on the outside of the impeller is it better if I took a photograph?? I have never seen actual flames just puffs of smoke every time its backfires or any ever spitting out. The engine I painted when I went and replaced the drive shaft like over a month ago. let me know thank you.

Joey
 
When the boat is out of the water and you rev it up it'll "hit" the rev limiter and retard the timing causing it to slow/bog down. The "smoke" you see coming out of the carb is actually the atomized fuel charge being pushed out of the motor. This will happen if the valve is not timed properly, by being closed, as the piston begins its downward movement. So, I'd start off by making sure the valve is timed properly. You will need to be able to get the #1 (front) piston to TDC (top dead center) in order to install the valve correctly.

I can scan the procedure for timing the valve for you but you will need to be able to get that piston to TDC first.
 
PWCdoc said:
When the boat is out of the water and you rev it up it'll "hit" the rev limiter and retard the timing causing it to slow/bog down. The "smoke" you see coming out of the carb is actually the atomized fuel charge being pushed out of the motor. This will happen if the valve is not timed properly, by being closed, as the piston begins its downward movement. So, I'd start off by making sure the valve is timed properly. You will need to be able to get the #1 (front) piston to TDC (top dead center) in order to install the valve correctly.

I can scan the procedure for timing the valve for you but you will need to be able to get that piston to TDC first.
Click to expand...

I appreciate all your help so far, I have made sure it was timed properly several times, I don't know if it changes anything but it started to backfire before I did anything the with the RV valve, so can the RV Valve just get out time by random or do you have to remove the cover and that's the only way? So what I am saying is can the RV get out of time just by riding the Seadoo?

This all started when it started to bog it not backfire it was just bogging it was doing same thing on the water as on land I would hit "WOT" and it would bog and rev down alot and continue the cycle until I would let go of the gas. Shortly after that it started to Backfiring and Bog/slow, so In previous post someone told me it was the RV timing so I went ahead made sure it was timed properly and it did not change anything. Then if you look back few previous post I found a major exhaust leak so I replaced the valve and It actually fixed the Backfiring problem and bogging issue, but the day I took it to the lake I found out that a engine mount was broke and the Carbone ring had broke and the driveshaft got bent:(, so after I go to remove the engine and replace the driveshaft it starts the same backfire and bogg/slowing. If something was not clear please let me know I appreciate your help so much.

Joey
 
oring

hey why does a guy need o ring at rotor valve is there one in front and behind it on the splined shaft?????:willy_nilly:
 
The rev limiter is built into the MPEM. That's why I mentioned checking the clearance on the impeller. Too much clearance will allow the motor to rev up higher and make it hit the rev limiter.

Also, how did you go about determining top dead center? And which piston (front or rear) did you check for TDC?
 
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Reving to high will cause backfiring?

PWCdoc said:
The rev limiter is built into the MPEM. That's why I mentioned checking the clearance on the impeller. Too much clearance will allow the motor to rev up higher and make it hit the rev limiter.

Also, how did you go about determining top dead center? And which piston (front or rear) did you check for TDC?
Click to expand...

Thanks alot, I will try to get a photo of the impeller clearance, so if you the clearance on the impeller is off this will cause it to rev up higher than the rev limiter and thus causing "Backfiring"?? I checked the the rear piston the one nearest to the fuel tank we used a pencil to make sure it was top dead center.

I really appreciate your replies

Joey
 
When you checked your rotary valve timing, did the valve have wear on it? My 97 gtx had minor wear marks and was really hard to start and bogged and backfired. I changed the rotary valve and it ran perfect, unfortunately I blew a piston about an hour later and I am currently rebuilding(ring spread and chipped piston).
 
salmonkiller01 said:
When you checked your rotary valve timing, did the valve have wear on it? My 97 gtx had minor wear marks and was really hard to start and bogged and backfired. I changed the rotary valve and it ran perfect, unfortunately I blew a piston about an hour later and I am currently rebuilding(ring spread and chipped piston).
Click to expand...

Make sure your timings' right. stud...
 
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