82 Sportfire (not happy)

Technical topics related to machines powered by Kasasaki motors
MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

Just got this sled last weekend, and I'm trying to get the bugs out. I'm thinking most of the problem is stemming from the carb(no airbox, leaking float bowl, choke broke). Got a lead on a flat slide 34mm. carb for $50 for a 250 Quad racer. Should this work with some jetting? For now I've road it a few times and it sounds like its about to pull a holeshot and then the power dies and it surges until it gets to it's max of 25m.p.h. This is my first sled and don't know what to look for as far as common problems on this machine don't want to break it and have nothing for all of this beautiful snow we just got. Thanx
Matt
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82 Sportfire (not happy)

Post by Matt »

You're best bet is to read the "Troubleshooting your sled" in FAQ to get started. Lots of things to cover.
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400brian
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82 Sportfire (not happy)

Post by 400brian »

Do yourself a favor and keep things simple. Fix the carb that is on the sled, then the guys here can help you, otherwise, you are all on your own.

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MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

Put new carb on had a 250 main and the needle was on the 3rd rung(didn't work well). I put in a 210 main and set the needle to the 4th rung(much better still no bottom end). Tried adjusting side knob to 3 turns out and still no get up and go. Don't know what to change if I move to the 5th rung what will it do? To add to the first setup all it would do is engage clutch but not move. Also it doesn't want to idle and the cable set screw is almost backed all the way out, I adj. the idle set screw to 1 1/2 turns out what else can I adjust to get idle? Thanx
Last edited by MIGreg on Fri Dec 19, 2008 4:34 pm, edited 1 time in total.
MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

Here's a couple more questions. Is the only way to put bolts in the motor thru the engine mount plate to pull it completely out of the front or am I missing something? Also what is the top speed on a sportfire 440? This may give me an idea of how much fun I'm missing with this fresh snow :doh:
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427cobra
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82 Sportfire (not happy)

Post by 427cobra »

Well lets see...

4 bolts hold the engine to the plate
4 bolts hold the plate to the chassis

There are holes in the belly pan that you can use to access the motor bolts if you wanted to remove the motor and leave the plate in place. But it would be easier to remove the plate bolts and take the plate and motor out together.

i would definatley use the correct carb for the Sportfire. Which is a Mikuni powerjet carb. You just need go through the carb and make sure everything is clean.

Not idling is usually caused by a bad crank seal/low compression. That could cause your power loss too. It may be only running on one cylinder..??
Last edited by 427cobra on Fri Dec 19, 2008 5:36 pm, edited 1 time in total.
Eric A.

"Life is tough, but it's tougher when you're stupid" - John Wayne
MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

The biggest issue with the original carb was the choke was seized looks like someone removed the cable and spring and left it open to the elements. I soaked it in ZEP for about 3 hrs. blew air through every hole and even used some force but it wouldn't move. I hope it's not seals wouldn't surprise me though I always have a way with buying money pits. I didn't see the holes to put the bolts back in the block though thanks for the heads up. I thought flat slide carbs are supposed to be superior in performance to the antiques. The best part of buying the sled is the guy told me it would keep up with his brothers Indy. Oh the joys of being a dope!!! Sorry for the rambling I worked midnights and have been up since 2pm yesterday, spent all morning trying to figure this sled out.
Last edited by MIGreg on Fri Dec 19, 2008 5:57 pm, edited 1 time in total.
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427cobra
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82 Sportfire (not happy)

Post by 427cobra »

If the choke plunger is stuck in the carb....

Just use a flat head screw driver to give the plunger a twist which will free it up and up should be able to remove it!

I usually let the carbs soak at least overnight if they are dirty.

The Sportfire should be a pretty quick sled when running properly.

As far as the seals go...they are pretty cheap (less than $10 for both) and easy to replace on these SF air cooled motors.

Good luck.
Last edited by 427cobra on Fri Dec 19, 2008 6:16 pm, edited 1 time in total.
Eric A.

"Life is tough, but it's tougher when you're stupid" - John Wayne
MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

The problem with new seals is I have to pull the motor and when you do that it needs to be ported and polished, bored,and high comp. pistons must be added :dance:
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427cobra
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82 Sportfire (not happy)

Post by 427cobra »

:beers; True!!
Eric A.

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82 Sportfire (not happy)

Post by ICCSF 108 »

Why would you port & polish a fan cooled single carb sled engine?? That has a top speed of maybe 65 MPH?? If you wanted a performance sled you maybe should have concidered purchasing one in the first place..
Yes the flat side carbs are supose to be better thean the VM carbs, problem is there are no Starting point specs for setting them up on a Deere Fan or Liquid engine..
By any Chance are You realated to BOB from MASS??
Kenny
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"God I love the smell of KLOTZ in the morning, That smell, you know that Gasoline/Oil Smell, MAKES the whole place SMELL like.. LIKE VICTORY. You know someday the 2 strokers are gonna end..."
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Matt
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82 Sportfire (not happy)

Post by Matt »

Hey Kenny, why do guys mod and race 295cc 1-lungers?
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JDT
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82 Sportfire (not happy)

Post by JDT »

In my opinion the lure of one lung racing is it levels the playing field and allows one to be competitive on a limit budget.

While they may only hit 55 on the track the excitemnt is still as good as the guy with a $8000 motor in a snopro chassis.
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MIGreg
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82 Sportfire (not happy)

Post by MIGreg »

Looks like I should pull and put some work in to it. I imagine since the engine bolts are missing on one side and loose on the other,the previous owner didn't care to much about it.I read something about crank seals do you need to have a machine shop replace these? I shouldn't be frustrated you can't expect a brand new sled for $150. As for the old carbs choke I did crank on it with a screwdriver after spraying it with AeroKroil it just snapped one of the ears off the top it's pretty well lodged in.
Last edited by MIGreg on Sat Dec 20, 2008 9:15 am, edited 1 time in total.
ICCSF 108
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82 Sportfire (not happy)

Post by ICCSF 108 »

Matt, I would have to agree with Todd cheaper to do just one cylinder Than 2 or 3, & know matter how much you spend on them you are probably only going to get so much HP also for the novice racer you can still be competative.
My own experiance is that IF I would have grassed dragged the 295/S a dealer gave me to use back in 74 I would have been more competitive & wouldn't have spent 1/3 rd of the money I did running the big 650 twin & 3 cylinders, too bad I thought I was so smart back then, LOL

Kenny
AKA: Kenny, Grumpy, Mr. Richard Head
"I Hunt For it, Purchase it, Haul it, Sometimes Repair it, Sometimes Break it, Then Fix it Again, Label it, Warehouse it, Talk About it, So NOW, HOW Can I Take Any Less $$ For It?"
"God I love the smell of KLOTZ in the morning, That smell, you know that Gasoline/Oil Smell, MAKES the whole place SMELL like.. LIKE VICTORY. You know someday the 2 strokers are gonna end..."
Do Anti-War Protesters have reunions? If so what do they TALK about?
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