250 sl start-stall help!

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Brian_H. - 10/25/06 at 1:21am

My dad has a Hodaka 250 SL ('76 or '77) in great shape with 400 miles on it that he has owned since new that I am trying to save. He has given up and just wants to scrap it, but I want to save it.
Here's the story...The bike always ran great until it sat for a few years then it wouldn't start. We drained the fuel and put a new plug in it and it fired right up, ran for five seconds, then died and wouldn't start again. We took the plug out again and it was soaked, so we cleaned it, put it back in, and it did the same thing; ran for five seconds and died.
After some messing around I found the baffle on the muffler plugged with weeds and such. I cleaned that out and cleaned the plug again and it ran great. Rode it around the yard a few times then took it back in the woods. About a mile into the woods it died and wouldn't start again. Pushed it back home and after some messing around found some junk in the main jet of the carb. Rebuilt the carb and cleaned the plug again and once again it ran perfect. And once again got about a mile in the woods and it died!
After a lot of swearing I took the exhaust off and drained about a quart of oil out of it, cleaned the plug yet again and got it to run again, but it had absolutely no power at all. After I shut it off all I can get it to do again is run for five seconds.Every time I pull the plug it is soaked like its flooded. A some-what reliable source told me that it could be that the piston and/or bore might be messed up but I hate to tear it down due to the rarity of parts like gaskets and such.
I have been a chevrolet mechanic for 12 years, but two strokes are still a mystery to me. I have read a lot of your forums and it seems that you guys are the gurus of Hodaka's and I hope that you can help me save this one. Any help would be GREATLY appreciated because I grew up on this bike, holding on to the gas cap for dear life as my dad ripped through fields on it. I would hate to see it go!
Thank you,
Brian
P.S. I forgot to mention that the oil injection has been removed and now the fuel is just mixed 20:1 if that makes any difference.

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thrownchain - 10/25/06 at 8:55am

Brian, thx for wanting to keep the Hodaka alive. Ok, I'll try to tackle these one at a time. Is the gas tank very clean? It seems to me that you're getting a lot of residue in the carb, flush out tank and put in an inline fuel filter. Have you checked the air filter?? could have the same problem as the muffler [ something living in it.] What kind of oil was in the pipe?? Does the bike smoke a lot?? Have you done a compression test? Have you got good blue spark?? What part of the country are you in?? Keep in touch and we'll get you running again. Dan

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Bullfrog - 10/25/06 at 7:58pm

Oh my! While there could be more to the story, I'd guess that a rusty fuel tank and resulting dirty fuel are all that are standing between you and some fun!
As has already been recommended, remove the fuel tank and clean it out thoroughly.
Install an "in-line" fuel filter when you reassemble the tank on the machine.
Re-fill with 40:1 fuel mix (or the pre-mix ratio recommended by the OIL manufacturer). Note that I worked for Hodaka in Athena . . . and we didn't run 20:1 pre-mix on general use machines in the 1970's! The ratio recommendation molded into the fuel cap and published in the various owner's manuals is a left over relic of the early '60's when two stroke oil was actually standard motor oil!
Clean and re-oil your air cleaner element. (It might fall apart in your hands as you clean and oil it -- meaning it should be replaced.)
Have fun!
Ed

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Earl - 10/25/06 at 10:19pm

Brian, Also check your transmission oil level!! The oil in the exhaust sounds like your tranny side seal may have dried up and went away on you. Is the plug, oil fouled or fuel fouled? If it is oil, I would bet on a shot seal and probably extra pressure in the exhaust due to oil and coking. Earl 8)
PS The bike is worth saving!!!

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bobwhitman - 10/26/06 at 2:13pm

Ed & others- OK, expanded questions relating to oil/pre-mix, triggered by Ed's mix ratio comments: For those of us who've been away since the 70's, can we safely run 40:1 premix in our Hodies for general use? Any sage advice re: which oils are suggested//not? Also, how does one assess whether an intact injection system is working properly (without waiting to fry the motor)? I understand there are no shop manuals for the injection bikes; are there any alternative sources of info (eg: how much fork oil to use, injection queries, etc) for maintaining 02s & 03s?
Bob Whitman

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Bullfrog - 10/26/06 at 6:39pm

Get the Owners Manuals. They list capacities (fork oil). They also discuss oil injection adjustments - ?"bleeding" too?
I ran 40:1 at Bad Rock, Trask Mountain, Ft. Hood and other ISDT Qualifiers in the 1970's . . . and I'm running 40:1 now. You saw at Chehalis that the scooter runs pretty well, it just needs a better nut on the handle bars!
Of course there IS this bit of information: Harry Taylor tells me that dyno tests proved that 26:1 is the best pre-mix ratio for MAXIMUM horsepower. Apparently more oil doesn't lube enough better to make up for the loss of gasoline per unit volume of pre-mix thru the carb. Conversely, while less oil allows more gasoline per unit volume through the carb, friction losses start to go up. Hmmmmmm, mayhaps I should start playing with 36:1 or 32:1????? (I haven't talked with HT about plug life and 26:1 for enduro/trail riding.)
Ed

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Earl - 10/26/06 at 8:19pm

Bob, Like Ed, I run 40/1 in my Hodakas. I have never had an oil related failure. I like AMZOIL and Maxima in that order but any good name brand oil will work. I have a friend who will only run Golden Spectro. Earl 8)

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Brian_H. - 10/26/06 at 10:29pm

Wow! Looks like I came to the right place! Thank you everybody for the great advice. Seems like you all know these bikes pretty well. It's probably a little bit of everything that you have mentioned. I checked the trans oil and it is very low so that is probably what the main problem is. I took a look in the tank and even though I did take it off and wash it out last year, there is some sediment at the bottom. With it probably burning the trans oil, I'm sure running it 20:1 isn't helping matters with the plug which is oil fouled. Mice have since ate the air cleaner (and a few wires too) since its been sitting so I'll have to find another one of those or adapt something.
Thank you again, and I promise that I won't let this bike be turned into beer cans!
Brian

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bobwhitman - 10/27/06 at 1:37am

Brian-
for a start on air cleaners, go to K&N website for universal filters, get the right dimensions and buy a knock-off from your local dirt bike emporium. I got 2 for different sized Mikunis for about $17@. gets the bike running and breathing at minimal cost & complexity.
Bob in OR

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