hey guys i justed joined the site in hopes that someone could help me out. last year i was rewarded with my dads 78 SR-500. its an awesome looking bike, the deal was if i could get it to run then it was mine. long story short it took replacing the battery, a new spark plug, cleaning out the carb and buying a new needle valve to get it to turn over and run. so i once i get it running it was blowing out black smoke. my dad suggested let it run for a while and just in case its needs to get all the old junk out.(it hadnt been started in 10+ years) so i thought it might be old gas so i drain the tank and carb to fill the bike up with some new gas. well its still running like that and if i try to take it out it starts to idle funny and dies. plus it wont rev past 3.5k i believe. whatever suggestions you guys have that could help me out would be appreciated. one of my goals is to get this bike up and running so i can drive it to work this year. i need your help.

hey guys i justed joined the site in hopes that someone could help me out. last year i was rewarded with my dads 78 SR-500. its an awesome looking bike, the deal was if i could get it to run then it was mine. long story short it took replacing the battery, a new spark plug, cleaning out the carb and buying a new needle valve to get it to turn over and run. so i once i get it running it was blowing out black smoke. my dad suggested let it run for a while and just in case its needs to get all the old junk out.(it hadnt been started in 10+ years) so i thought it might be old gas so i drain the tank and carb to fill the bike up with some new gas. well its still running like that and if i try to take it out it starts to idle funny and dies. plus it wont rev past 3.5k i believe. whatever suggestions you guys have that could help me out would be appreciated. one of my goals is to get this bike up and running so i can drive it to work this year. i need your help.

sounds like your burning oil. need to check valve seals as they may have hardened with age. Also the piston rings could have stuck allowing oil to get past. I assume you have checked the oil levels, i think the SR is dry sumped, oil in frame?

yeah i checked the oil level and thought there was too much so i drained a little. sounds like you know the bike. the oil does run through the frame. whenever i can work on it again i will check the oil level to see whats up.

sorry gotta bump it up. anyone else have any suggestions?

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you could be wet sumping, where the non return valve from the oil tank drains into the engine rather than stays put. the oil pump may not be able to scavenge the oil quickly enough. Iwould also check for any oil gauzes as they block up and not help with oil flow.

the amount of oil in your engine could prevent it from turning over 3.5k revs.

Well, I sympathize. I've got a '78 SR500 that I can kick 'till the cows come home.

If it decides to run, it goes and idles fine, but... I'm trying a coil now, having already

rebuilt the carburetor and checked the valve timing.

The funny thing is, evryone who comes by wants to kick it. It's like they all have the

magic foot, and they just know she'll start for them. It's become a community project.

Well, I sympathize. I've got a '78 SR500 that I can kick 'till the cows come home.

If it decides to run, it goes and idles fine, but... I'm trying a coil now, having already

rebuilt the carburetor and checked the valve timing.

The funny thing is, evryone who comes by wants to kick it. It's like they all have the

magic foot, and they just know she'll start for them. It's become a community project.

the key to good starting singles is technique and spot on ignition and valve timing

this may be a silly question but have you checked your air filter? also check your plug to see if there is oil on it. leave the plug out and kick it over and see if your blowing any oil out of the hole. i bought mine in 78 and also had trouble with the ignition electronics box. (the black box) it caused the same thing you are describing. and if you get tired of it and wanna sell it let me know, im lookin for one

OK If it were wet sumping it would start fine but you'd get clouds of BLUE smoke. There will be so much smoke you'd be convinced there is something seriously wrong with the engine. However the smoke will clear after a few minutes running and it'll continue to run absolutely fine. The fix is replacing the rubber seal in the non return valve in the clutch cover. Not a big job.

Your starting problems will be caused by the carb. You will need to replace all the rubber diaphragms, and springs etc. There are three diaphragms on these carbs and when they become hard they don't respond as they should and you get no end of starting problems. Leaving the bike unused is the most common cause of this.

The next item for concern is the fact it doesn't run over 3,500RPM.This could be caused by the carb, even so I would carry out a resistance check of the generator windings that power the CDI. If the high speed winding has failed, and they do often, this will mean the engine won't rev past 3,500RPM. Its easy to check with a multimeter and I can let you have the info if you don't already have the manual. The only fix is a generator rewind.

I do have an SR i want to sell, in the UK.

OOPs, just seen the date of the original post!

I'll close the topic now