I noticed you mentioned cleaning the carbs but did you check the plugs, wires and caps? I’ve had a bad cap cause all kinds of issues.
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Stupid question - brake light on cluster
- Thread starter Wrenchmorethanride
- Start date
Wrenchmorethanride
XS650 Enthusiast
I’ll give you the run down…
79 stock
Probably sat for 20+ years without starting
I drained old gas.
I rebuilt cards and set to factory specs.
Changed oil, cleaned filters
Old air intakes were toast, have new ones but not in yet
Before doing any of the steps mentioned below my brother was visiting and he had a jump start pack and we started the bike. Somewhere I have a video of it. Seems to run fairly well. Better than now. Then steps below are after I got the battery and tried to start it again months later.
I checked cam chain tensioner and it is very slightly out, just a hair. Tried to adjust but couldn’t get it to budge
I adjusted valves per spec
I set point gaps and adjusted timing
I changed plugs and set gap to .025 - that’s what old ones were. I got autolite plugs
Got new battery but I kept draining it trying to start it. I had to jump it to get it to start.
Seem to run better with choke on. I could give it some throttle and it would rev up good. If I left choke on and no throttle it would die after a bit. If I took choke off it would idle lower and then die. I think with choke on it was idling around 2k. Didn’t see what it was without choke.
Sorry for the long response but wanted to give complete info.
Any advice would be appreciated!!
Can’t ride my snowmobile so might as well get the 650 going.
Wrenchmorethanride
XS650 Enthusiast
Another note. I started working in the bike earlier today and battery voltage was 12.3. I only have a stupid battery trickle charger. After trying to start again voltage was down to 11.5 or so. Had to connect to a spare boat battery.
You say you drained the old gas but did you clean the tank? Might have had some varnish or trash, especially in the petcocks that can mess with your carbs. If you used Autolight plugs then if they are resistor plugs then you need non-resistor wires and caps. you can takes the whole cam tension assembly out by removing the cover. My concern would be if the threads won’t turn is the plunger free?
Sounds like you might have a power drain. Check the tech section for your wiring diagram. There are also links to manuals.
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Wrenchmorethanride
XS650 Enthusiast
I looked inside the tank and it is very clean. Bright shiny metal, no rust.
I didn’t clean petcocks but can try that. I was thinking that since it ran pretty good before that it might not be petcocks, but who knows.
I have the old plugs. Let me throw them back in and see what happens
I’m not sure about cam tensioner. I’ll have to investigate
Wrenchmorethanride
XS650 Enthusiast
I have Haynes manual and was trying to decipher the wiring diagram. Could it be that my battery doesn’t meet spec? It is 12ah and 180cca
I know my battery is around 225 CCA so not sure how much you cranked the bike over but even on a trickle charger it should get something. Haynes manual will get you close but nothing beats the factory book. There are links for those also.
https://www.xs650.com/threads/continuity-testing-made-easy.49917/
I find it easiest to find my electrical diagram in tech and print it out on a larger sheet. It’s right in front of me.
https://www.xs650.com/threads/continuity-testing-made-easy.49917/
I find it easiest to find my electrical diagram in tech and print it out on a larger sheet. It’s right in front of me.
Tell us a bit more about the carbs - you rebuilt them to factory spec, but did you clean out the various passages? Petrol, especially with alcohol content, will go gummy over time and can block or partially passages and jets.
Wrenchmorethanride
XS650 Enthusiast
I took it all apart. Tossed old parts, cleaned each passage way with carb cleaner and blew out with compressed air. Then put in new parts from rebuild kit.
Where did you source your parts? A lot of the kits you buy online have generic parts that cause more issues than help. I hope I’m not sounding too negative but I’ve gotten great advice on here or had to learn the hard way(HHS, hard head syndrome). Sometimes the issues can be frustrating but just about all can be worked out.
Wrenchmorethanride
XS650 Enthusiast
I welcome all advice. This is my first bike, so it’s new to me and I could have made a mistake somewhere along the way.
I do have experience working on cars, atvs, snowmobiles, mowers, etc…. But don’t claim to be a pro by any means
Here’s the rebuild kit I used https://daminedingmoto.com/deluxe-carburetor-carb-rebuild-kit-78-79-xs650-carb-float/
Let me know what you think
Earlier in thread someone mentioned the autolite plugs need different parts to work right. I think tonight I’ll swap back to old plugs just to eliminate that possibility
Its been a long time
Doesn't know nothing.
There's parts missing in that kit. Needle, needle jet and needle jet O rings most obviously. You need to check what's installed versus the correct carburettor parts listed in this website.
When working on the carbs, did you set the correct float heights?
Are carb diaphragms both in good condition?
Wrenchmorethanride
XS650 Enthusiast
I did set float height.
Let me check tonight. I did the rebuild back in May. I may have the old parts in a bag (ya I’m a packrat)
Wrenchmorethanride
XS650 Enthusiast
Update. I swapped back to the old plugs. After some attempts I got her to run. Idled at about 1k, no stall. Throttled up good. Wish I knew how to upload a video
Wrenchmorethanride
XS650 Enthusiast
I hope I did this right.
That doesn’t sound bad but the best idle speed is around 12-13K
I'm going to go back and visit your Taillight situation and clarify some information posted.
There are 2 different light units on the 78SE and 79SF.
One is a light checker and the other is a Reserved lighting unit. he light checker i an oblong box and checks for a failed taillight. This has both the brake-light circuit, (front and back), feeding into the the light-checker, and the taillight circuit feeding into the light checker. A failed light bulb or broken wire or switch in either circuit will trigger the failure light, (Red), on the Gauge cluster/Tower on the Red/Blue wire. Light checker also warns if the headlight fails to work through the Safety relay.
The Reserve lighting unit will switch power to either high or low beam if the other filament has blown. If low blows it will witch to high beam and my understanding is, it is a reduced power load so it will not interfere with oncoming traffic. This triggers the white light on the Gauge cluster tower
Some people advocate removing the Reserve lighting unit. Personally i like to have a running headlight day or night. If by chance the bulb blows i like the idea the headlight will still work so others, (cars) have a better chance to see me in the daytime, and if by chance i am night riding, having a device to automatically switch the bulb to the other beam could be the difference to either staying on the road or crashing due getting disorientated in the dark
There are 2 different light units on the 78SE and 79SF.
One is a light checker and the other is a Reserved lighting unit. he light checker i an oblong box and checks for a failed taillight. This has both the brake-light circuit, (front and back), feeding into the the light-checker, and the taillight circuit feeding into the light checker. A failed light bulb or broken wire or switch in either circuit will trigger the failure light, (Red), on the Gauge cluster/Tower on the Red/Blue wire. Light checker also warns if the headlight fails to work through the Safety relay.
The Reserve lighting unit will switch power to either high or low beam if the other filament has blown. If low blows it will witch to high beam and my understanding is, it is a reduced power load so it will not interfere with oncoming traffic. This triggers the white light on the Gauge cluster tower
Some people advocate removing the Reserve lighting unit. Personally i like to have a running headlight day or night. If by chance the bulb blows i like the idea the headlight will still work so others, (cars) have a better chance to see me in the daytime, and if by chance i am night riding, having a device to automatically switch the bulb to the other beam could be the difference to either staying on the road or crashing due getting disorientated in the dark
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Ooops - best idle speed 1200-1300?
Ok maybe it’s 1100 is best for most.
