new question old problem.

[original420racing]

I have a 89 sp and it will run all day perfectly.until i shut it off then it is hard to start.I have replaced the rotary valve cover and still does the same thing(it was iffy).when i pull the plugs they are dry like no fuel going to them.It has a primmer on it and if i pump the crap out of it it will start run like crap for 10 sec or so and then be fine until i shut it off again.

I have been having this problem for a while and would like some ideas on what could cause this.

 

[mike_dmt]

Maybe a fuel tank vent? Next time you shut it off, pull the fuel cap. If you hear air whoosh air in, there's vacuum in the tank.

Do you have the choke on the carb still, or just a primer? Do you have to prime it much when cold too?

 

[Bills86e]

If you have .010 RV clearance, your fuel routeing delivery system is clogged or your carb(s) were not properly cleaned or rebuilt.
My guess is you did not apply the instructions.

 

[original420racing]

no choke just primer.most of the time it starts with no primer at all.I dont think its a carb issue it runs very good for a yellow motor.I had a local guy build the carb and he is good.But the ski has always had this weird problem just has gotten worse last couple times out.

I will look at the fuel system .Ive tried the gas cap thing and no change.I got the rotary valve from you bill thanx again.

mine was in the low 20s and some deep grooves ish no worse than i seen on a couple.

Ive applied all the information i can...lol.I have had a few skis over the last 3 years.with the help of this forum mostly reading crap for hours on end .

It has helped a whole lot .skis are kinda new to me but i'm catching on.I have enough tools to do more than most 20 years worth of auto tools/ welders/ benders ect

I like the challenge.I usually can figure out these problems...but this ski is my favorite and i cant figure it out.

 

[Sportster-2001-951C-Stock]

Sounds like a lean restart, pumping the primer dumps fuel in and it runs rough while the excessive amount is clearing out. Maybe go a little easier on the priming(to avoid flooding) and check the pop-off, sounds too high?

Absent having the benefit of any numbers, I'd think about going one size lower on the metering spring.

 

[original420racing]

I was thinking of buying a billet adjustable pop off pressure plate off ebay to maybe try to tune it in easier.

but i will look into the spring also .

 

[Sportster-2001-951C-Stock]

Yeah, I'm not sure I like the idea of the adjustable cover, OEM's didn't see a need for something like that as far as I know. I have considered drilling a small hole in the center so I can stick an object in there and open the metering valve manually, but decided no since it's a PITA to get to anyway, so what would be the point.....?

I'm betting the pop is just a little too high. Every motor has it's happy settings and some guys just don't understand how pop really works I guess, the kit comes with springs and those go in without regard, black, silver, gold, what's your favorite color, right? There are two silver springs, too, and they aren't the same weight.

 

[original420racing]

what would you suggest for pop off pressure .I know what it should be stock.
I have done a couple carbs since having this one done .so now i feel cocky...lol

ski has a westcoast intake/ 44 carb w kn filter /high compression/and the purple pipe/lightweight flywheel and pto


I didnt do this carb so what would be a good starting point

 

[Sportster-2001-951C-Stock]

what would you suggest for pop off pressure .I know what it should be stock.
I have done a couple carbs since having this one done .so now i feel cocky...lol

ski has a westcoast intake/ 44 carb w kn filter /high compression/and the purple pipe/lightweight flywheel and pto


I didnt do this carb so what would be a good starting point

Who knows for sure till you try, you might need the next weaker spring in there to get the carb to flow. First, I'd be tempted to open up the low screws and see if I can get it to 4 stroke some in the idle, just a little more vacuum signal back to the diaphragm might be enough.

 

[original420racing]

I will play with the low speed adjuster on sat