my 1998 gp 1200 runs mint and the plug readings are showing that the mixture is correct.my question is i have heard alot about the check valves creasing and the filters in the carbs getting dirty ,so should i rebuild the carbs or leave them alone and check plug readings time to time,the ski has 215 hours on it.also iam ditching the oil injection.what ratio should i mix,32:1,50:1 ect,and do i need to rejet,or just open up the mixture screws.the motor is stock with 20 hours on complete top end.

anyone???

As an old automotive mechanic that OH carbs, the answer would be no. The rule of thumb in that world is that you never OH a carb unless needed.

But were living in the marine world with our ski and would be interested what others will say. With that many hours, it would be hard to beleive that the fuel pump is not pluged meaning that the carbs need OH.

thanks for info greg

thanks for info greg

With that many hours it would be a good idea to take off the carbs and do a visual inspection of the filters and rubber gaskets. By now you may have some cruddies in the filters and mabey some deposits in the carb circuits. now do the carbs have 215 hours on them also or 20 hours like the motor
if youre not gonna add performance parts i dont feel you need to rejet but you can if youre gonna add flame arresters and stuff like that

I use pennzoil synthetic at a 50:1 ratio on a raider 1100 ( modified)

carbs have 215 hrs on them

bump

come on guys,anyone else have opinion's

bump

have you ever checked your performance at WOT with an aftemarket tach or Tiny Tach?

7150(tiny tach)wot stock prop 215 hrs ,i have heard of check vavle problems with these carb's.if one or more carbs were in the need of overhaul ,woudent the plug reading show lean.all three plugs are tan at wot.i dont want to open up a can of worms ,but if enough people tell me to overhaul carbs,i will.215 hrs on carbs,20 hrs on top end

Hey Wave, I think that I have a set of take offs here in the garage. Low hours and have fresh water use. Drop me an e-mail if interested. Thanks, Travis
If any one is interested I have a set of beach house sponsons for the same machine....$110 plus s/h.

Wave

It has been my experience with the GP1200 that when the check valves go bad your potential of lean seizure at WOT is eminent. It appears that yours is running fine especially turning that type of rpms. What have you done to your GP1200 to get those r's?

Do you have any experience with carbs? Have you replaced your stock fuel filter? How long do you do WOT runs? Why are you going to pre-mix? Do you really want to learn about carbs? I personally don't feel that they are difficult to pull apart and if you can pull the injection system you should be able to pull and overhaul the carbs.

You may want to check the group K website for tech advise on the GP1200 carbs and check valves.

MD ,thanks for the reply,iam all stock,i think iam getting those rpm's due to my prop is worn.the only reason i was thinking about going to pre mix is of relibilty,i would love to keep my oil injection but everyone seems to say dump it and pre mix????.need advise

MD,also yes i allways change the fuel filter and i usally run it at 3/4-w.o.t throttle

7150 rpm with a stock GP1200 is unheard of.

You must have some very worn impeller blades or a tiny tach that is not operating correctly.

My opinion, if your leaving it stock, is to retain the oil injection system and do some more WOT runs on glass water for at least 1 to 2 miles in length while watching the tach. If the tach maintains a maximum rpm of 7150 and does not drop at all for the entire distance, then leave your carbs alone.

Have you ever adjusted the high or low speed adjusters on your GP?