550sx timing?

[Jaystewart23]

What is the stock timing on the 550sx? I bought a reed motor off a friend with a bunch of parts. Replaced the crank seals and and gaskets. It was missing the stator and flywheel and carb. Bought a sbn44 and machined flywheel and stator in good condition from a guy for a good price. I lined up the stator with the case halves but was reading there is different stators. The engine won't fire unless I use the primer and only runs for a second and then backfires out the exhaust. I rebuilt the carb new jets 100 pilot and 120 main with 2.0n/s I think at 20 psi pop off. I think I'm having a timing issue but not sure where to start. The ski also is ported polished and machined head.

 

[TaintlessEd]

What is the stock timing on the 550sx? I bought a reed motor off a friend with a bunch of parts. Replaced the crank seals and and gaskets. It was missing the stator and flywheel and carb. Bought a sbn44 and machined flywheel and stator in good condition from a guy for a good price. I lined up the stator with the case halves but was reading there is different stators. The engine won't fire unless I use the primer and only runs for a second and then backfires out the exhaust. I rebuilt the carb new jets 100 pilot and 120 main with 2.0n/s I think at 20 psi pop off. I think I'm having a timing issue but not sure where to start. The ski also is ported polished and machined head.

You answered your own question in a way.
Since you’re back firing you need to start with timing most likely. At least that’s where I would start.
Verify you have the correct stator as well.

You mentioned port and polish and machined head. What PSI are you running and what fuel are you using?


Sent from my iPhone using Tapatalk

 

[Jaystewart23]

You answered your own question in a way.
Since you’re back firing you need to start with timing most likely. At least that’s where I would start.
Verify you have the correct stator as well.

You mentioned port and polish and machined head. What PSI are you running and what fuel are you using?


Sent from my iPhone using Tapatalk

Not sure about PSI about to grab a compression tester and check but I'm using 91 with VP octane booster. Any idea what the reed motors are supposed to be timed at, 21,25 or 28? Never really messed with timing before but I guess I'm going to learn this one way or another haha. Any tips would be appreciated. Thanks.

 

[fastgtfairlane]

simply line the stator mark with the case halves. to advance the timing move the line on the stator above the case halves. i wouldnt go anymore than about a penny thickness above the case halves with 91 octane. and i wouldnt use octane booster either. mix 110 and 91 to raise the octane levels.

 

[Jaystewart23]

simply line the stator mark with the case halves. to advance the timing move the line on the stator above the case halves. i wouldnt go anymore than about a penny thickness above the case halves with 91 octane. and i wouldnt use octane booster either. mix 110 and 91 to raise the octane levels.

It is currently lined up with the case halves. And what's your reason for not using the vp octane booster? Still going to check the PSI tonight on each cylinder I will post later

 

[TaintlessEd]

simply line the stator mark with the case halves. to advance the timing move the line on the stator above the case halves. i wouldnt go anymore than about a penny thickness above the case halves with 91 octane. and i wouldnt use octane booster either. mix 110 and 91 to raise the octane levels.

It is currently lined up with the case halves. And what's your reason for not using the vp octane booster? Still going to check the PSI tonight on each cylinder I will post later

So what’s the PSI


Sent from my iPhone using Tapatalk

 

[Jaystewart23]

Hey sorry my buddy asked me if I wanted to go to the river (Blythe,CA) last minute so I just took out my 750sx still have not checked. I will be working on it today to figure out compression. Some others people were telling me I might have got a stator where the pulser coil was replaced and installed backwards. Sounds like they have similar symptoms to what I'm experiencing. Going to do a resistance test first and see if the coil is good or maybe backwards.

Sent from my SM-N950U using Tapatalk

 

[Jaystewart23]

Its 155 psi on each cylinder

Sent from my SM-N950U using Tapatalk

 

[Jaystewart23]

Checked resistance on the stator seeme good. Still not able to tell if the pulser coil is backwards. Anybody know how to check if it's on the right way?

Sent from my SM-N950U using Tapatalk