Sonoran Dave Posted June 12, 2017 Share Posted June 12, 2017 (edited) I've regretted selling my old dirtsquirt since I did it. I have seen more of the local desert on it than anything else. TomH to the rescue! I helped Tom figure out his rear differential last fall and we(mostly he) just rebuilt the transmission in his yota. My prize was this poor ol' 89 RM250 sitting forlornly under a tarp in Tom's backyard. Back in the days of her youth she was a steed to be reckoned with. I'm going to try and bring her back up to snuff. Edited June 12, 2017 by ArcticDave Grammer 8 Quote Link to comment Share on other sites More sharing options...
heybeerman Posted June 13, 2017 Share Posted June 13, 2017 Nice! 1 Quote Link to comment Share on other sites More sharing options...
Swampstomper Al Posted June 13, 2017 Share Posted June 13, 2017 Was gonna say she looks purt good until I noticed the gear cover's off.. If only it was that simple though.. Why do I get the feeling a piece of aspirated metal = beat to chit piston & cylinder..? Swamp Quote Link to comment Share on other sites More sharing options...
homefire Posted June 13, 2017 Share Posted June 13, 2017 You talking about the Front Drive Sprocket ? Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 13, 2017 Author Share Posted June 13, 2017 Swamp, they all have exposed drive socket anymore. Engine is good. Tom changed neck and swingarm bearings and cleaned it up. The idle climbs on it I guess. Probably a large intake leak leaning the mixture. It needs tires and a few other things before it gets ridden at all. 1 Quote Link to comment Share on other sites More sharing options...
Swampstomper Al Posted June 14, 2017 Share Posted June 14, 2017 Kewl.. That was the anesthesia talking anyhow -- can't even see yet.. Put that keyboard down before you hurt someone, son.. Okay -- I go to my room now, yes..? Good idea (pat, pat..) Byeee.. 1 Quote Link to comment Share on other sites More sharing options...
weaver hillbille Posted June 14, 2017 Share Posted June 14, 2017 (edited) Reed valves and exhaust port could be carboned/clogged- common problem , of course, unless 100:1 synthetic Juju. It was SOP back in the day to pull the head and decarbon piston/combustion dome, deck the head, race gas or octane booster, raise the needle, richen the mains, and detonate the motor.. Then break out the torch and bake the carbon out of the siliencer. Edited June 14, 2017 by weaver hillbille Quote Link to comment Share on other sites More sharing options...
weaver hillbille Posted June 14, 2017 Share Posted June 14, 2017 (edited) 5 hours ago, ArcticDave said: . The idle climbs on it I guess. Probably a large intake leak leaning the mixture. The carb( needs rebuild) slide might be gummy from sitting and old gas. Leak an unlit propane torch all around the intake plumbing-away from the airbox.- and it should bump the idle more , if leakin. I think bulk gasket exhaust material could fashion as OEM reed valve gasket, if you tear those down to access intake ports, if needed. Edited June 14, 2017 by weaver hillbille 2 Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 14, 2017 Author Share Posted June 14, 2017 Tom said he replaced the reeds and thats when it started happening...I think. I'll tear into it when I have the money to fix it. It has a Pro Circuit pipe and with new reeds it may just breathe too well! I have seen this happen when the crankcase seal behind the flywheel goes bad. Sucks a large amount of air right into the bottom end. The leak leans the mixture and boom....idle climbs out of control. We'll see how it goes. I've got to clear out some space for it inside, as I might just tear it all the way down and do a complete restoration on it. 1 Quote Link to comment Share on other sites More sharing options...
weaver hillbille Posted June 14, 2017 Share Posted June 14, 2017 1 hour ago, ArcticDave said: just breathe too well! I have seen this happen when the crankcase seal behind the flywheel goes bad. Oy, now I remember splitting cases for that exact reason... shop wanted megabucks.. Check out the dogs in the trans when you get to that point: the 1-2 shift tends to go first when it ramps/wears enough to slide out of gear. Racers used to reverse ramp the dogs so it would pull the gear in. 1 Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 14, 2017 Author Share Posted June 14, 2017 I'll watch for that when I pull it apart. Thanks Weav! Quote Link to comment Share on other sites More sharing options...
homefire Posted June 15, 2017 Share Posted June 15, 2017 22 hours ago, weaver hillbille said: Reed valves and exhaust port could be carboned/clogged- common problem , of course, unless 100:1 synthetic Juju. It was SOP back in the day to pull the head and decarbon piston/combustion dome, deck the head, race gas or octane booster, raise the needle, richen the mains, and detonate the motor.. Then break out the torch and bake the carbon out of the siliencer. I remember using the REAL Naphtha Moth Balls to get things going. Gave you a few more ponies ! Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 15, 2017 Author Share Posted June 15, 2017 Moth balls??? Quote Link to comment Share on other sites More sharing options...
Au Seeker Posted June 15, 2017 Share Posted June 15, 2017 5 hours ago, ArcticDave said: Moth balls??? https://www.google.com/search?q=Naphtha+Moth+Balls&oq=Naphtha+Moth+Balls&aqs=chrome..69i57&sourceid=chrome&ie=UTF-8#q=More+horse+power+using+Naphtha+Moth+Balls 1 Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 15, 2017 Author Share Posted June 15, 2017 I see. About like the acetone wives tale. Lots of claims with no real data to back it up. A friend of mine swears adding acetone to his tank increases his power and mileage. I tried it a couple of times and noticed zero difference. I filled up his truck once after borrowing it and didn't add the acetone like he asked. He had noticed no difference when asked about it later. Undoubtedly it makes for a dandy injector cleaner, but that's probably the extent of its benefits. 3 Quote Link to comment Share on other sites More sharing options...
homefire Posted June 20, 2017 Share Posted June 20, 2017 No Wives tale. It worked quite well in a Suzuki 250. Melt 4 in a pint of gas and add it to a full tank. Gave you noticeable added power ripping in the desert. 1 Quote Link to comment Share on other sites More sharing options...
homefire Posted June 20, 2017 Share Posted June 20, 2017 For a while if you bought gas in Mexico here down in Polomas they was using Crap Gas at the tank with Naphthalene added. You could tell if you got some it would smoke bad. Not from the Naphthalene but the Crap Gas. http://www.hho4free.com/additives/naphthalene.html Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 21, 2017 Author Share Posted June 21, 2017 I wonder what makes it work? Gas already contains 3-7% naptha derivatives. They used to use it straight as fuel, but the octane is really low and it will cause a modern engine to pre-detonate if used uncut. Coleman fuel is almost straight naptha... that might be a easier way to get it. Quote Link to comment Share on other sites More sharing options...
homefire Posted June 21, 2017 Share Posted June 21, 2017 (edited) Yep, Coleman fuel aka White Gas is hot as hell. Not so sure I would try that strait up in a Two Stroke. They run hot to start with. Did get my hands on a gal of Nitro Drag fuel one time. A cup of that in the tank livened things up most well. Popped a hole in a piston doing that one. Spark plug had melted aluminum glued to it. I think it would had worked if I cranked up the Auto Oil Injection or added oil to the mix. LOL Belonged to a Amateur Moto X club for a while . Think everyone did the moth ball thing back then. Gave that up when they decided running over someones head while they was down was fair game. People have played with all sorts of mixes. I never got past the moth ball thing to the most parts. Edited June 21, 2017 by homefire Quote Link to comment Share on other sites More sharing options...
Swampstomper Al Posted June 21, 2017 Share Posted June 21, 2017 2 hours ago, homefire said: ...Belonged to a Amateur Moto X club for a while... ...Gave that up when they decided running over someones head while they was down was fair game... You too, eh..? I was into the sport realll early on ('60s,) until right after the same basic thing happened to me.. To be fair I did go down at the bottom of a blind whoop -- not the best spot on a track to eat it.. All I could do was lie there half under the bike until everyone else went by n we could get me n the bike outta the next lap's way.. Considering my situation I think I handled getting run over pretty good.. Don't think I would have handled a direct landing-upon quite as well though.. Ironically, this also happens to be the very same day I realized just exactly how much pleasure could be derived simply from cruzin' our highways & byways on a scoot.. Weird, huh..? Swamp 4 Quote Link to comment Share on other sites More sharing options...
homefire Posted June 21, 2017 Share Posted June 21, 2017 LOL ! Yep, Avoiding running over a few folks cost me placing in a few races. Found the open desert just as challenging. Three or four of us out zipping around ram roding with out the threats. Way more Cool. 2 Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 21, 2017 Author Share Posted June 21, 2017 Roaming the desert is more fun for me too. Had a blast doing it on the old yamaha. Lots of single track trails here...some of them are straight flippin sketchy though. I've been really close to needing a diaper change a few times riding here. 2 Quote Link to comment Share on other sites More sharing options...
homefire Posted June 21, 2017 Share Posted June 21, 2017 Wish I had like a 25o again. Plenty of places to go you can't do in a truck around here. 1 Quote Link to comment Share on other sites More sharing options...
Sonoran Dave Posted June 21, 2017 Author Share Posted June 21, 2017 Same here man. A bike will go many places a 4 wheel rig can't. A lot faster too Quote Link to comment Share on other sites More sharing options...
homefire Posted June 21, 2017 Share Posted June 21, 2017 Yep. Just limited on what you can haul with you. Not a problem for exploring and detecting. 1 Quote Link to comment Share on other sites More sharing options...
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