1999 gtx ltd poor idle

[darren1965]

Greetings members, this is my first post (on any internet site) so please forgive any mistakes and advise me of correct procedures.
2 weeks ago I purchased a 1999 gtx ltd with a seized motor caused by salt water ingestion and thanks to your premium membership offer I was able to rebuild it useing your on line workshop manuals and user manuals.
I have not owned a pwc for near 20 years and was very excited to get back into high speed mode (last pwc was 440 kawasaki).
My possible problem is that the machine missfires quite badly at idle or light throttle,problem dissapears on acceleration. Keep in mind that I am running about 70:1 2 stroke oil (tcw3) on top of the oil injection system and I am also using 0.08 plug gap because I could not find my feeler gauges. on top of this, the fuel could be up to 6 months old. I will re-gap the plugs before the next outing, but I would like to get your ideas on any other causes.
Work carried out: re-bore 0.05, new pistons ( 0.05 obviously ) New crank and rods (taiwanese unfortunately). Carbs and magneto untouched.

 

[seadoosnipe]

Wrong oil!

Sea-Doo strongly warns of not using a TCW oil. This will cause engine damage. Your motor requirements are a Non TCW, Non NMMA, low ash oil. If you can't use the Seadoo blend, then you can go to Wal Mart and get the "Quick Silver" blend, designed for the Sea-Doo's.......read the label on the back, it will have the Sea-doo recommended type oil listed. And make sure you run the same blend in both the injection tank and the pre-mix. If you were running a mineral oil and went to a synthetic, you needed to clean all the oil from the system. Do not run this engine until you get that oil out!.....VERY IMPORTANT.....Your a premium member, look in the back of the manual, in the tech specs pages and you'll see your requirements. Need any further assistance on this, just ask!
As for your light backfiring.....that could be from your Rotary valve being one or two degrees off. It says they can be +/- 5, but I think it's better to be as right on as you can be.............Good luck....:cheers: