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Discussion Starter · #1 ·
Smokin\'

hey everyone, I'm having a weird occurance with my 84' 250r. When I'm out riding, it will run perfect, have good power every where and run just like it was meant to be. But lately, it never seems to want to clean out, it will never reach the top..then some other times it will run fine, like nothing ever happened. I'm running 32:1 Amsoil, a little rich since its air cooled...could i also run a bit leaner of a ratio? it ran strong and fine on 32 to 1 before, what could be it? -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
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Discussion Starter · #2 ·
Re: Smokin\'

I overheard a conversation this weekend between a couple of 250R guys about transmision oil leaking past the crank seal and causing a similar problem. The oil level in the gearbox dropped noticeably. Something to think about?
Pete
 
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Discussion Starter · #3 ·
Re: Smokin\'

hmm hope my crank bearings arent on their way out!! /wwwthreads_images/icons/blush.gif Can i run my ratio any leaner then 32:1 or shouldnt I since its air cooled? if so what can i run it at? I'm using amsoil racing synthetic currently. -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
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Discussion Starter · #4 ·
Re: Smokin\'

When you speak of never reach the top, do you mean top end?

SInce it seems intermitent, i would look for vaccuum leaks at the rubber manifold connection on either side of the carb.

-cleartoy
 
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Discussion Starter · #5 ·
Re: Smokin\'

Yeah sorry, I meant it would never reach the top end of the power band without sputtering and smoking, doesnt really clean out either, plug is all black and gummy, it used to be tan..if it were and air leak wouldnt it be running lean? -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
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Discussion Starter · #6 ·
Re: Smokin\'

Your main jet may have vibrated loose. Check that it is still in it's proper place.

Check the small stuff too...Air filter, new properly gapped plug, fresh fuel, so on.

If there were an air leak typically it would run lean.

--Backcountry
 

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Re: Smokin\'

Have you checked the mixture screw? I have seen where they can be issues of either getting dirty or vibrating loose. What is your compression and leakdown test results? It seems to me beings as it is intermittent, that you could have a sticky ring that gets planted and stays for a while. I would go through the carbs and if you do not find anything, pull the lid off and check the rings.

Just my $.02

AirBorn!!
 
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Discussion Starter · #8 ·
Re: Smokin\'

Okay a tear down is in order then! The engine hasnt been rebuilt in ages, but they used 20:1 with what ever oil they had, gear oil, out board etc.../wwwthreads_images/icons/mad.gif, So I'm betting the condition of everything inside is gummy but fine inside, may need a new top end, but compression seems to be good. What ratio can I run it at now with a good quality 2 stroke oil like amsoil? I'm using 32:1, but I'm afraid I'm not taking advantage of its full synthetic-ness. any ideas? -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
/wwwthreads_images/icons/laugh.gif
 

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Re: Smokin\'

I run 25:1 approximately in my 94 banshee 350...it treats me well and i use yamalube R. I have had great luck with it...also the motor has been ported and polished...I dont think 32:1 would be a bad number scheme...

AirBorn!!

AirBorn!!
The good Lord giveth and the Eco-Nazi's Taketh away! Long Live the ORV!!!
 
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Discussion Starter · #10 ·
Re: Smokin\'

wow doesnt it smoke?
since I'm running Amsoil, I was wondering if I should run it at maybe, 40:1. it being air cooled, but then again, its a synthetic oil, it might be designed to perform better at a leaner mixture, but then again, I'm new to 3 and four wheelers /wwwthreads_images/icons/smile.gif. my neighbor ran it wide open acorrs a big hayfield today and it smoked like hell....might have a bad tranny seal? but hardly smoked any after a took a short full throttle blast up my long drive way. hope the bearins arent on their way out! /wwwthreads_images/icons/blush.gif -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
/wwwthreads_images/icons/laugh.gif
 
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Discussion Starter · #11 ·
Re: Smokin\'

I run Bel-ray MC1 at 40:1 to 45:1. They reccomend "up to" 50:1. Does Amsoil have any reccomendations? It depends a lot on the oil. Yamaha says 24:1 for Yamalube R, but I think that's due to the formulation of the oil. I do know that oil and plugs are cheaper than pistons, so feed it well. It sounds like your smoking problem is an abnormal condition, so fix that first. Have you been keeping an eye on your gear oil level?
 
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Discussion Starter · #12 ·
Re: Smokin\'

I'll have to check what ratio they reccomend up to, it seems to be running alot better when I turned the air screw in, its about 2.5 turns out now, used to be way far out /wwwthreads_images/icons/smile.gif. my gear box oil level as remained about the same too, providing the people I got it from didnt fill it way over the oil check hole. is it possible to tighten axle bearings? I dont know if theyre tapered or what not, they seem to be getting a little loose though.../wwwthreads_images/icons/blush.gif. -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
/wwwthreads_images/icons/laugh.gif
 
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Discussion Starter · #13 ·
Re: Smokin\'

You can try snugging the axle nuts, but that probably won't work for long. My guess is they're ball bearings. Tapered rollers are available with aftermarket carriers, but probably not stock. /wwwthreads_images/icons/tongue.gif
Pete
 

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Re: Smokin\'

My rear on mine loosens up a little on me too. I tighten it up after every ride and then cover it with tape again...It it does get old though....but would rather do that then replace the carrier bearings on the back...

AirBorn!!
The good Lord giveth and the Eco-Nazi's Taketh away!
 
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Discussion Starter · #15 ·
Re: Smokin\'

Airborn, sounds like you're due shortly for new bearings if you have to tighten them often./wwwthreads_images/icons/frown.gif In the unfortunate event of a re-do, drill a hole in your carrier and put a zerk fitting in. Then remove the inner seals from the new bearings and drill very small holes in the outer seals to allow excess grease to escape without dislodging the seal. Pump it full, and give it a few shots after each ride. Your next set will last forever./wwwthreads_images/icons/laugh.gif I've also done this to the swingarm.
Pete
 

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Re: Smokin\'

It has a zerk already there and it is lubed every ride. On the Durablue I have there is no lock on the nut so when you pound it and really get on it hard it loosens up... I just took the bearings out and checked them about 3 weeks ago and they are all tight and look very good still. I am not worried about that part at all...it is being taken care of very well...just gets tiring sometimes hehe

AirBorn!!
The good Lord giveth and the Eco-Nazi's Taketh away!
 
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Discussion Starter · #17 ·
Re: Smokin\'

Too all who dont understand these mixtue ratios, all synthetic motore oils work best at 32:1 to 50:1 raios on liquid cooled engines, 32:1 for a 500cc liquide cooled motore and 50:1 for 125's and 250' even a banshee running this new KLOTS BeBol and other synthetics like KLOTS R 50 2 stroke oil should be mixed at 50:1 or else it will gum up the power vaves if you have them and badly cloge the inside of your exhause pipe.

As for factory oils yamalube and kawasaki oils they should stay between 24:1 & 32;1

low ratio
24:1 = 1 gallon fuel and 5 oz oil <~~ rich with oil
32;1 = 1 gallon fuel and 4 oz oil
40:1 = 1 gallon fuel and 3 oz oil <~~ lean with oil
50:1 = 1 gallon fuel and 2.5 oz oil Dont go any leaner that this
high ratio

Klots R 50 racing oil recomends mixing at 50:1 for best resulte and less carbon build up in pipe, chambers and power valves

woodsracer
99 cross country banshee
99 dodge quad cab 4x4
 

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Re: Smokin\'

Well, that was VERY well done man...and very easy to understand. However, I will pay the price of yamalube myself. I also will keep running at 25:1 or so....It seems to run best at that ratio...anyway...just wanted to tell ya great job on the research!!!

AirBorn!!
The good Lord giveth and the Eco-Nazi's Taketh away!
United we stand..Divided we fall..LETS UNITE!
 
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Discussion Starter · #19 ·
Re: Smokin\'

hey woodsracer, EXCELLENT research job, in my case, you didnt mention anything about air-cooled engines like the ones in my yamaha IT dirtbike, my yamaha DT dirtbike and who could forget the good ol' 250r? /wwwthreads_images/icons/blush.gif! -Mike

74' DT100 78' IT175 84' ATC250R 85' K20 88' CR250R
/wwwthreads_images/icons/laugh.gif
 
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Discussion Starter · #20 ·
Re: Smokin\'

BIG BORE AIR COOLED ENGINES SHOULD RUN A MUCH RICHER MIX LIKE 24:1 AND 20:1
THE BIGGER THE BORE ON AIR COOLED ENGINES THE RICHER YOU NEED IT LIKE 400 - 500CC. A 125 OR AN 80CC STROKE AIR COOLED YOU CAN RUN 24:1 TO 32.1

ANYTHING ELSE i FORGOT TO MENTION? :)

woodsracer
99 cross country banshee
99 dodge quad cab 4x4
 
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