MexicoJoe
Member
Hey guys, I have another question for this wonderful Seadoo forum that has been a huge help to me previously over the past few years. I recently had an issue with an internal short on the MPEM for the ignition circuit. Without going into all the detail I will put the hyperlink below if you want to read about that.
Starter Engages When Battery is Connected 97 GTX
Essentially, to keep this short, I had an internal short in the MPEM that was providing 12v to the starter signal wire as soon as the ground was hooked up to the battery without the key on the DESS post. Myself and a few others on the forum (JeremyD615) (Ckrawiec) verified and confirmed it was the MPEM. I purchased an Arieltek MPEM brand new from Bay Area Powersports and installed it. Here is the part that I would like some suggestions with regarding the timing curve and ignition timing.
The Arieltek MPEM can be programmed to advance or delay the timing as well as the rev limit. Here is where I'm at currently; I was having some trouble identifying the Engine Identification Number next to the serial tag on the bottom end housing of the engine above the PTO. When I first looked at it, I thought it was potentially a 1 or 7. Then if you look closer, it almost appears as though there is another faint etch that makes it look like it's possibly a 4. Now, as some of you know and by reading a few other posts where MATT BRALEY gives excellent advice on ignition timing there are 8 EIN's. Numbers 2,3 and 4 are timing advance. EIN #1 corresponds with 0°. Numbers 5,6,7 and 8 correspond with delaying the ignition. Because I was having trouble identifying the EIN on my case due to the etch being so faint I took a picture and sent it to my girlfriend who works at a local authorized Seadoo dealer here in PHX,AZ. She showed the picture to a tech with 20 years experience that had also confirmed our original issue with the internal short. He sent me back a text saying that number is a 7. So I programmed the MPEM to EIN #7 which corresponds to -3° timing delay. The ski fired right up and idled at 3k as per normal.
Yesterday, I took the ski out to the lake to give it a test ride. Ski seemed to be running in the ballpark of where it had been for the 2 years I've owned it (GOOD). However, and here is where I need a little help. The ski was on it's way up the engine curve to WOT and then it started bouncing off of the rev limiter at 6100rpm per the digital tach on the info center. I can confirm this is due to the MPEM and not the water regulator or any other issue related to the engine or rave valves. My first thought was I guess I will have to raise the rev limit. I'm not positive this is the issue after putting some thought into this and reading through some of MATT BRALEY's ignition timing education posts. The Arieltek MPEM is supposed to come out of the box set at 7200 (same as factory) so I didn't program or mess with the rev limiter. After thinking about this and having a better understanding of timing advance and delay, I'm starting to assume that I have the timing delayed too much (loss of power on top). Piston is already traveling down when the fuel is fully ignited.
Back to yesterday's lake day trial. I did NOT bring the simple instructions with me so I didn't know how to program the rev limit. I really didn't want to open up the grey box on the water and re-program the ignition curve because I was already starting to think that the #7 on my case is actually a #1 and wanted to run this by you guys first. Essentially, can Matt or any of the other pros here confirm what I'm thinking? I'm thinking that my ignition timing was giving me the lack of top end. Below 6100rpm the ski seemed to be running fine as it has the two years I've owned it. Since we didn't want to call it a day I just kept my trigger finger off of the throttle at WOT so we didn't bounce off the rev limiter all day and hurt the engine. At 6100rpm it sounds just like a TWO STEP on a turbo application lol I know for a fact it's the rev limiter but again, could the ignition timing being delayed 3 or 4° make it lose power on top and give a false rev limiter situation? I want to do this the correct way and not raise the rev limit to 8 or 9k. The EIN #1 corresponds to 0° and if my EIN is actually a #4 then it would correspond to 1° of advance so basically I'm thinking I'm about 3 or 4° delayed too much. I have read a post where Matt describes using the EIN #2 designation to get 3° advance timing without detonation or engine heat building. Because I obviously don't want to destroy the engine should I just try to increase my timing advance one degree until the ski starts running normal at WOT or go straight to 3° correction and see what that does for me?
Sorry for the lengthy post, I only strive to be as descriptive as possible not to confuse anyone and for you guys to get a better understanding of what I'm describing. Thanks in advance to anyone willing to take some time out of their day and give a fellow Seadoo lover some advice and to anyone that has already helped out. Seadoo forum FTW!
-Joe
Starter Engages When Battery is Connected 97 GTX
Essentially, to keep this short, I had an internal short in the MPEM that was providing 12v to the starter signal wire as soon as the ground was hooked up to the battery without the key on the DESS post. Myself and a few others on the forum (JeremyD615) (Ckrawiec) verified and confirmed it was the MPEM. I purchased an Arieltek MPEM brand new from Bay Area Powersports and installed it. Here is the part that I would like some suggestions with regarding the timing curve and ignition timing.
The Arieltek MPEM can be programmed to advance or delay the timing as well as the rev limit. Here is where I'm at currently; I was having some trouble identifying the Engine Identification Number next to the serial tag on the bottom end housing of the engine above the PTO. When I first looked at it, I thought it was potentially a 1 or 7. Then if you look closer, it almost appears as though there is another faint etch that makes it look like it's possibly a 4. Now, as some of you know and by reading a few other posts where MATT BRALEY gives excellent advice on ignition timing there are 8 EIN's. Numbers 2,3 and 4 are timing advance. EIN #1 corresponds with 0°. Numbers 5,6,7 and 8 correspond with delaying the ignition. Because I was having trouble identifying the EIN on my case due to the etch being so faint I took a picture and sent it to my girlfriend who works at a local authorized Seadoo dealer here in PHX,AZ. She showed the picture to a tech with 20 years experience that had also confirmed our original issue with the internal short. He sent me back a text saying that number is a 7. So I programmed the MPEM to EIN #7 which corresponds to -3° timing delay. The ski fired right up and idled at 3k as per normal.
Yesterday, I took the ski out to the lake to give it a test ride. Ski seemed to be running in the ballpark of where it had been for the 2 years I've owned it (GOOD). However, and here is where I need a little help. The ski was on it's way up the engine curve to WOT and then it started bouncing off of the rev limiter at 6100rpm per the digital tach on the info center. I can confirm this is due to the MPEM and not the water regulator or any other issue related to the engine or rave valves. My first thought was I guess I will have to raise the rev limit. I'm not positive this is the issue after putting some thought into this and reading through some of MATT BRALEY's ignition timing education posts. The Arieltek MPEM is supposed to come out of the box set at 7200 (same as factory) so I didn't program or mess with the rev limiter. After thinking about this and having a better understanding of timing advance and delay, I'm starting to assume that I have the timing delayed too much (loss of power on top). Piston is already traveling down when the fuel is fully ignited.
Back to yesterday's lake day trial. I did NOT bring the simple instructions with me so I didn't know how to program the rev limit. I really didn't want to open up the grey box on the water and re-program the ignition curve because I was already starting to think that the #7 on my case is actually a #1 and wanted to run this by you guys first. Essentially, can Matt or any of the other pros here confirm what I'm thinking? I'm thinking that my ignition timing was giving me the lack of top end. Below 6100rpm the ski seemed to be running fine as it has the two years I've owned it. Since we didn't want to call it a day I just kept my trigger finger off of the throttle at WOT so we didn't bounce off the rev limiter all day and hurt the engine. At 6100rpm it sounds just like a TWO STEP on a turbo application lol I know for a fact it's the rev limiter but again, could the ignition timing being delayed 3 or 4° make it lose power on top and give a false rev limiter situation? I want to do this the correct way and not raise the rev limit to 8 or 9k. The EIN #1 corresponds to 0° and if my EIN is actually a #4 then it would correspond to 1° of advance so basically I'm thinking I'm about 3 or 4° delayed too much. I have read a post where Matt describes using the EIN #2 designation to get 3° advance timing without detonation or engine heat building. Because I obviously don't want to destroy the engine should I just try to increase my timing advance one degree until the ski starts running normal at WOT or go straight to 3° correction and see what that does for me?
Sorry for the lengthy post, I only strive to be as descriptive as possible not to confuse anyone and for you guys to get a better understanding of what I'm describing. Thanks in advance to anyone willing to take some time out of their day and give a fellow Seadoo lover some advice and to anyone that has already helped out. Seadoo forum FTW!
-Joe
