Power loss help

[UCXS650]

Just got the bike its got a severe power loss 1 of the floats was stuck,
Ive gone through them and unstruck the float... but haven't checked it with the carbs back on the bike yet
P/O said even before they were stuck it was still giving him trouble.

-Was low on oil when I got it, and was barely within specs
-Sounded like it has a little bit of a rod knock.
-Has a oil leak coming out of the first cylinder (doesn't smell like gas, thick and smells like oil)
-is only a few drops when sitting. who knows when its being riden
-Didn't have the right thread too check the compression but turning it over felt like it was decent .

Thanks in advance

 

[azman857]

We'd like to help ya. Ya gotta let us know what we're working with though. Year,model carbs,exhaust, etc. Pics are good too.
Welcome to our corner of the web. Please tell us your plans for your ride, a bit about you, your rideing experience etc.

 

[weekendrider]

UCXS650
Welcome to the site.
Do you have a manual? If not you can download the service manual at this site.
http://www.biker.net/650_service/650service main.html
One of the first to do's is cam chain adjustment and valve adjustments.
Download and read the carb guide.
http://www.amckayltd.com/carbguide.pdf
This and more information is in the tech section. Tech tab is at the top.
Another suggestion is to click the control panel (on the tool bar).
On the side bar you can "edit your signature". In the signature you can give us some info about your bike. Year, model and anything else you can confirm like carbs 38's or 34's, stock or aftermarket ignition things like that. You can see examples in other folks posts about what I'm talking about. This helps to narrow down what you are working with without having to ask .

And yes I don't any info in my signature. I don't really own a motorcycle. I just like to troll the site

 

[UCXS650]

Thanks for the replies guys, Has been a busy few months...I'll stay more active now as I finally have some time too get this back on the road.

Been working on bikes for awhile now. Work 9-5 to come spend that money on my bikes 5-10, This will only be my third rebuild so i'm hoping too get as much info as you'll throw out my way.


Its a 81 Engine, with mikunis I can get the model number if you guys need it,
Ended up just tearing it down after compression check went something like 60-90 dry
140-90 wet.
Was beat up and run low on oil,
Sent it too the shop too have some head work done and they can't/Dont want too find parts for it.
So now Im looking for.
X2 exhaust guides
4 Valve stems
And a set of pistons..

 

[UCXS650]

I know some of your eat sleep and breath xs650 if you throw your opinion out there for me I need 75.5+ without having too Re-sleeve. thanks tons.

 

[azman857]

You mentioned you tore the engine down. How far? Hows the crank and rods. Are they in spec? Bearings show wear/overheating or are they good? Crank run true and not twisted? I've put several hundred miles on a exhaust valve from Mikes's XS and no problem. 650 central is a good place to get almost everything too.
A cleanup on the ports will help the top end. Nothing major. If you can pick up a XS1/256 cam will help. Just remember to swap the chain ring an maybe when the chain ring is installed consider retarding the timing a touch. Not essential though.
You mention Mikuni carbs. VM's or stock BS34's? Either work. Proper jetting is a must!
Stock bore will handle 75mph all day long.

 

[UCXS650]

I've torn it down too the pistons, Cam bearings? they look good
Rods have a little bit of freeplay but I think there okay, Im on a budget.. like everyone else, the headwork I estimate will be around 600, W/Parts
Im going to end up grabbing these.

http://www.ebay.com/itm/like/400412307954?lpid=82
https://www.mikesxs.net/product/01-0114.html
And 2nd size over rings and pistons from 650 central.

I have a used xs motor I've been playing with while the heads in the shop, And I've been able too tear it down and re-Time it with the camchain still in tach?

 

[angus67]

wow. you think 600 for head work?
I had a piston let go of the pin, cramming itself in the head, I took it all apart my self, Had a shop shave the head to make it flat, recut valve seats, I put it all back to gether with valves from mikes, new DID cam chain, 50$ out the front door of the shop.
But I had heard the mechinist there had a fondness for 650's. still though. you can still tear the head all apart and give a shop a already torn down head, that way all they have to do is guides, valve seats, and maybe a shave

 

[UCXS650]

Sounds like you got hooked up
65$ For each cyl bore=130
Valve work= 125
Are prices for labor.

+ Parts end up being around 600

 

[angus67]

I didn't factor in the cost of new valves. And I was just mentioning head work. not cylinder. I bought the 1.5 over cylinder kit from mikes, and took that to the same shop so he could make sure it would all work together.
Runs awesome. pulls out the hole quick, even with a 17 front sprocket.
The shop was a parts house for cars, but had heard about this guy thru various people.
Maybe he was just excited that he got to do something other than rotors and heads? don't know. both times I was in there, he wasn't there, so I couldn't get to pick his brain. but in any case, I only spent like a hundred bucks, 50 for the head work, and 50 for the inspection of bores/rings.
this was back in '07, I believe labor there was sposed to be 65$/hr.
yea, I scored.

 

[UCXS650]

Kind of a bummer I haven't met anybody cool around here that works on bikes, I had a cb650 I restored before this, and it ended up bogging down in front of a neighbors house in the troubleshooting stage, he was building cafe kawasaki tripple was kind of stoked about it ha. but checked back periodically over the year and he was over his head I guess, It just sat. Anyways Its nice too have someone too like you say "pick at there brain"