1983 XS650 New Owner and That Famous Whirring Sound

[Wano 21]

Excellent work buddy, you'll be on the road in no time at all!
I'm literally viewing a XS650 special tomorrow, just doing my homework prior to handing the cash over.
I look forward to seeing your video of it firing away, keep up the good work

 

[Leslie]

The infamous whirring sound, I first noticed this sound on my 90s FZR1000 exup but also recently my 79F

https://www.facebook.com/video.php?v=398485682039610

 

[Tlted_Jelli]

The infamous whirring sound, I first noticed this sound on my 90s FZR1000 exup but also recently my 79F

https://www.facebook.com/video.php?v=398485682039610

yup thats exactly what mine sounded like. both my chain guides were worn through and i had some really bad crank pinion wobble


@5twins

gotta re-bench sync my carbs i think but im getting a much stronger fire on my right cylinder than my left. left just seems weak and stumbly compared to the right which hums along very evenly and much louder. any thoughts? i'll see if i can put a video up

 

[Tlted_Jelli]

Here it is. Left side kinda hesitating and putting while the right is just rumbling along

 

[Tlted_Jelli]

Here it is. Left side kinda hesitating and putting while the right is just rumbling along

Update: Got it rumbling just right from both sides. Had to re-bench sync my 40+ year old carbs. Mixture is 1.25 left and 2 right.

Also as a note I found that I was missing the throttle cable bracket on the bs38 carbs like a lot of people and fabbed my own bracket up. 0.120 SST. Saw the only place online selling them was somewhere in China and they're all outta stock.

Anyway one I made works great with the bs38s and standard length cable from Mike's

 

[Tlted_Jelli]

So after going on my first ride after getting my license. I got around the neighborhood twice and was about to go out to the highway and right before the turn lost all throttle response. Engine was still idling well and I was able to ride the friction zone and do the duck waddle of shame all the way home.
Did all the top down checks I could remember. Compression, timing, valves, chain tension....all good.
Stupid 40+ year old bs38s + o look very rusty inside the tank. A lot of that rust made it passed my fuel filter. Could see flecks in the fuel line.

Any hoodles....ugh....my own fault for not cleaning out this old tank when I got the bike. Took the carbs apart and thoroughly cleaned them for the billionth time. Rechecked my synch and settings.
Then went about doing electrolysis on the tank and red koting the interior. Got a better inline filter and cleaned my lines.
Just before putting those old carbs back on I made the grand decision of buying a vm34 kit from Mike's....I've read the posts...I know haha
My bs38s we're on there last legs. Chipped up, stripped and retapped threads everywhere, brass plugs coming loose.

Anyway, we're running again after cleaning up and installing Mike's vm34 kit but now I need to familiarize myself with vm carbs and get them tuned. Pretty sure right now that the jetting that Mike's sets them up with is not gonna work for me. Any suggestions for sea level people's in NJ? I'm gonna read the carb guide and mikunis guide in the meantime.

Also made myself a skid plate. Anyone wants some old bs38s?

 

[1fatalZ28]

How did you like the red-kote? I've only ever used Kreem on my older tanks.

 

[miketweedie]

How did you like the red-kote? I've only ever used Kreem on my older tanks.

Not to thread hijack, but I have some experience with the stuff. I did my Buell cafe tank with it and have mixed reviews.
I had the tank professionally cleaned after fabrication, and followed the instructions to the letter. The first application completely failed, so I reached out to the manufacturer and after a good discussion they determined that my product had expired and sent me a replacement for the price of shipping.

I had to get the old stuff out, which was not fun. Gallons of MEK later it was clean and I started over. The second attempt worked really well and got the perfect thin coating they advertise. It also looks hilarious when the filler cap is off and the sun catches it.

Fast-forward, it's been in there for 3 years now and I am starting to see a pink tinge in my fuel leading to the filter. I added a second filter for the time being, as that stuff will jam up your carbs really badly, but I have resigned to the fact that I am going to have to strip it and find something else. The tank is completely custom, and there are tiny pin holes in it that we havent been able to seal without a coating, so it will need to have something.

 

[1fatalZ28]

Not to thread hijack, but I have some experience with the stuff. I did my Buell cafe tank with it and have mixed reviews.
I had the tank professionally cleaned after fabrication, and followed the instructions to the letter. The first application completely failed, so I reached out to the manufacturer and after a good discussion they determined that my product had expired and sent me a replacement for the price of shipping.

I had to get the old stuff out, which was not fun. Gallons of MEK later it was clean and I started over. The second attempt worked really well and got the perfect thin coating they advertise. It also looks hilarious when the filler cap is off and the sun catches it.

Fast-forward, it's been in there for 3 years now and I am starting to see a pink tinge in my fuel leading to the filter. I added a second filter for the time being, as that stuff will jam up your carbs really badly, but I have resigned to the fact that I am going to have to strip it and find something else. The tank is completely custom, and there are tiny pin holes in it that we havent been able to seal without a coating, so it will need to have something.

A buddy of mine had some issues with his on an old iron head tank is the reason i asked. I hear good and bad about it.

 

[jetmechmarty]

A buddy of mine had some issues with his on an old iron head tank is the reason i asked. I hear good and bad about it.

My own belief is that any solvent based liner is suspect. After the @Mailman debacle, if I use anything, it's epoxy. I have two lined with it, as yet untested.

 

[Mailman]

After the @Mailman debacle, if I use anything, it's epoxy.

If you want to see what a melted gas tank liner does to your engine have a look here,

https://www.xs650.com/threads/mailman’s-xs2-pulled-the-engine-for-top-end-repair.58865/

 

[joebgd]

I understand tank liner if as stated, it was necessary because of pin holes. Otherwise I've seen guys on here get them supper clean with the electricity cleaning. If you don't absolutely need liner just clean it and don't liner it.

 

[Tlted_Jelli]

Well I was cruising around on it everything going fine. I took it in and the last week I was playing with my headlight installing an LED and a new horn.
Took it back out and cruising around everything fine again. VM34s jetted 185, 22.5, middle clip, no main air.
Anyway cruising along in 3rd when all of a sudden revs drop dramatically and engine starts lagging, lights dim and flicker. Then it catches back up and cruises along again.
This kept happening for the rest of the ride till I got back home not dependent on what gear or rpms. Turned the headlight off too and still same thing. Maybe I have a short somewhere? It still idles real happy.
Not sure what's wrong. I only started having issues after messing with the electric. Almost like it's starving for fuel or I'm losing good spark for a minute.

Gonna go through the basic checks again but if anyone has any input I'm all ears.

I already took the carbs off again once and cleaned them out real quick...didn't notice anything in them. Still had the issue. Will check my valves, timing, and the rest tomorrow for due diligence.
*Edit did some reading and with the little 1.5watt LED I may have been overheating my regulator on my PMA kit from Mike's. Hopefully it's not shot. All inside my combustion chamber still looks very clean. I guess I'll put my halogen back on and give her another try. Ill probably test my coil and regulator first beforehand.

 

[Tlted_Jelli]

Well I recheck my valves and timing everything is set correctly. I tried testing battery voltage after kick-starting it.
14.6 volts steady until I revved to about 3000rpm then all hell broke loose. Engine started to just about die and it was idling very very rough. Voltage reading all over the place from 9 volts to just north of 11 volts.

I got a new reg/rec

 

[joebgd]

Yes. Reg rec sounds like a good place to start. Could very well be one. There are aftermarket car reg and home made rec guys are using with great success. I believe it's in the tech section.

 

[Jan_P]

Perhaps some wire vibrating at higher rev and shorting
I would try to remove fuses .Se if something changes
Specifically charging circuit fuse .since it should run on battery only a while
trying the 3 k rev

 

[joebgd]

That's a good point, I've had that happen where an intermittently loose connection was causing problems. It wasn't a big headache in my case cause I had an idea it was an inline fuse I just recently put in.
Could well be a bad connection getting aggravated when it revs.

 

[Leslie]

Ric (Smedspeed) has opened my engine, a few minor issues for a 44 year old engine, one of the crank bearings locating pin/dowel has been shoved right into the bottom case, we can assume that the whole bearing may be rotating and causing the whirring noise (Touch Wood). The depressed pin/dowel is at the end of the photo Ric has highlighted with the end of a screwdriver, thoughts opinions please

 

[gggGary]

I don't see strong evidence it's been spinning. Crankshaft needs to be measured, checked.
Balance plugs where they belong in flywheels?

hmmm.

 

[Leslie]

Lads, the cases are non repairable, so i have had a 750cc rephased (277) engine from Ric @ Smedspeed, should be with me within a couple of weeks photos and a video once the new unit is fitted and up and running.