I have been haveing trouble with my one engine for some time now. It had been hard to start and it idled low. So I Idled it up to spec and all seemed well. The one day i shut it off and now it wont start. I can only get it to start out of water and only for a few seconds. Today on the water I cranked and cranked, took plugs out and they seemed dry. It will only start out of water if you throttle up a couple of times to make the accelerator pump pump some gas and then if you give it gas it will backfire and stop. Carbs seem likely or could it be timing related? IT is a 717
-
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
97 speedster engine wont start and backfires
- Thread starter willxp
- Start date
- Status
Some things I just checked, it has good spark, I mixed a little gas and dumped some in carb and it made no difference, I dumped some in cylinders and it still wont fire. Is my motor toast? I dont have a compression tester but i put my finger over cylinders and it can pop my finger off.
- BiRkS_
Active Member
Depending on how much gas you put into the engine, you may have flooded it. Take the plugs out and put the wires on the grounding post. Put a rag over the spark plug holes and crank the engine for about 5 seconds. Re-install plugs and put A TINY amount of fuel in each cylinder. If that doesnt work and you do have spark, your flywheel key is sheared.-causing incorrect timing, making it not want to start. :cheers:
Dr Honda
Well-Known Member
Is it actually back firring out the carbs?
The only thing that would cause that is being very lean in the pilot circuit, or the rotary valve timing is off.
Regardless... if it is back firring, the carbs will need to come off, and be cleaned since the heat and pressure of a backfire can mess them up.
The only thing that would cause that is being very lean in the pilot circuit, or the rotary valve timing is off.
Regardless... if it is back firring, the carbs will need to come off, and be cleaned since the heat and pressure of a backfire can mess them up.
Yep I saw a flash and orange light and a pop in the throat of the carb when i push the throttle up. So I dont know. My time is so short nowadays and I found some local guys that fix skis so I took it over to him tonight. On that engine it has basically car plug wires with sea doo ends on them. The core of the plug wires was like a graphite. He thought that there would be a slim chance that was the culprit. I dunno. But he is gonna check the basics before he digs deep. I will post what he finds.
Well everything got put back together starts right up but no power. 120 psi on one 50 on the other. great what fun, I am gonna do a top end and i have a few questions. The jug on the bad cylinder dont have any deep scratches but when you run your finger over it it is bumpy. Do I order the factory size or a little over? Also the cylinder head dome got banged up, does that need replaced?
Well got it back together, seems to be running good. Engine broke in. Did a compression test, have 132 on one, 136 on the other. Is that ok? Also now my other engine has same symptoms as this one did before it tanked. I think the rotary valve housing is at its wear limit so I am going to replace that and go through the carbs. Compression on this engine is 130 on both. So I am hoping it should still be good.
- Status
