Carb issue with 1982 CR250...

[Steve Kirby]

I am new to racing old Huskys and I took the 1982 CR250 I just bought to the track this weekend and loved it! I have one issue that I need advice on - she came off line great and on top end was great - but in corners or over jumps when I left off gas - it "gurgled" like she was going to cut out. Not sure if she was starving for gas or getting too much, but it was definitely boggy. I took spark plug out today and it looks normal (bronze color) and I am running it 32:1 MC1 with non ethanol gas. The needle clip is set on top notch and air screw is 1.5 turns out but I haven't had chance yet to take carb completely off to see what size jets are in it.
Any advice on what could be doing this? I'm assuming it is carb based issue and not the electronics breaking down when getting hot?
I am open to suggestions and needing help - racing again in 2 weeks...

Thanks
Steve

 

[justintendo]

when you take down carb, make note of what size slide it has as well..if the bike pulls its best on the very top or bottom needle clip, a needle jet swap is needed

sharp looking bike too

 

[Steve Kirby]

Thank you - I will do that tomorrow- any recommendation on which needle to buy?

 

[Bigbill]

Corners and over jumps, the bike on angles, have you checked the float level or the needle and seat for leakage? You could have multiple problems. With the needle in the top clip that’s lean. I’d check the needle and seat, the float level, then go after the needle jet. Once you figure out it’s lean or rich. When the carb is adjusted.

I’ve had leaky needles and seats that had me pulling my hair out while trying to jet the bike.

Bigbill rule of thumb,

1st. When buying a used bike change the cylinder base gasket.

2nd. Clean the carb, check the jets for not being plugged up, check the float level and replace the needle and seat.

3rd. Clean or change your air cleaner.

 

[Steve Kirby]

Corners and over jumps, the bike on angles, have you checked the float level or the needle and seat for leakage? You could have multiple problems. With the needle in the top clip that’s lean. I’d check the needle and seat, the float level, then go after the needle jet. Once you figure out it’s lean or rich. When the carb is adjusted.

I’ve had leaky needles and seats that had me pulling my hair out while trying to jet the bike.

Awesome! Thanks for feedback - I will check that tomorrow as well...

 

[Picklito]

All good advice. What I'd recommend first, since you're in the very top clip, is to move it one position and then do the "better or worse" comparison. That's the best way to start deciphering what the engine is trying to tell you. It's quick, it's free, and it's immediately reversible. Go from there...

 

[motomwo]

Why is it when people have carb jetting issues they never take into account the weather conditions or altitude or air density ratio? It just baffles me because it should be a huge factor. For example Monday I rode my 81 420 auto. The area I ride this time of year is at 3900 ft altitude. I checked the weather conditions and the air density ratio was 101.6 (good air) and the corrected altitude was at 990 ft. so I had to go up a couple of jet sizes from when I last rode the bike last fall. Depending on the weather conditions this same bike has used main jets from 360-430. Just a thought.

Marty

 

[ruwfo]

I looked back at my 83 250CR log & it said mine had: 45 pilot 2.0 slide 430 main was changed to a 380.

If you got the stock silencer, throw it in the garbage, it's super restrictive, & try and find an Answer.

Ride it without the silencer & you'll see what i mean, hope that helps and i'm at sea level

 

[Bigbill]

It’s a hands on learning experience too.

My son jetted his bike and he says it runs great till the steep hill climbs happen on the trail. I was just thinking he’s running ethanol. We just changed to the non ethanol gas two stroke mix in my chain saws and there screaming now. Just one more thought it’s the ethanol gas too.

Sorry for the miss spelled words my spell check changes what I write.

 

[suprize]

seriously consider buying a new carb, old carbs can cause all sorts of issues you can chase for ever. muffler suggestion is a good one....

 

[Bigbill]

I purchased a gallon sized can with carb cleaner in it with a basket. You disassemble the whole carb and let it soak. It comes out new looking. All the passages are cleaned. Add a new bowl gasket and needle and seat, set the float and your ready to jet it.

If your needle and seat is leaking it’s impossible to try to jet it. I tend to replace the needle and seat too. Don’t forget the Husqvarna mikuni carbs take the higher flow needle and seats. There’s six extra holes above the hex so more gas can flow.

38/11 6 hole needle and seat. http://www.jetsrus.com/individual_parts/002_200_su.html

 

[dumpbear]

Bill where do you get gallon of carb cleaner with basket.
Tom

 

[Motoduc84]

I looked back at my 83 250CR log & it said mine had: 45 pilot 2.0 slide 430 main was changed to a 380.

If you got the stock silencer, throw it in the garbage, it's super restrictive, & try and find an Answer.

Ride it without the silencer & you'll see what i mean, hope that helps and i'm at sea level

Ride it without the silencer...will it be faster? Or, just sound faster?

 

[suprize]

a restrictive muffler effectively kills the top end.

 

[jimspac]

I actually bought a gallon of carb cleaner that came with a cleaning basket about seven years ago. I think I got it at Autozone.

 

[dumpbear]

Thanks Jim i will check that out.

 

[Motoduc84]

a restrictive muffler effectively kills the top end.

I race mx with my 250WR. Wish I could find a better muffler.