Author Topic: The $500 Challenge (Read 19834 times)

Tugboat · « **Reply #100 on:** April 22, 2014, 08:16:27 AM »

Yep - that seems to be the case. I wouldn't mind so much if it wasn't so much work just to get the thing off the bike. So it goes with this thing, I guess....

The kicker sitch:
As expected, the spring broke.

I was able to steal the spring off the parts bike. It is indeed a slightly different spring. The RH cover for the '74 bike is different too, and it uses a spacer of sorts inside the spring. Our '76 uses no spacer, and instead I believe that part of the cover takes up that space. I tried putting the spacer in and then the cover, but that didn't work. Seems to fit okay without the spacer. Kicker mechanism now moves as it should.

You know what's really fun? Scraping gasket material off a mounted motor! This was the best bit:

I cleaned up the cover really well and am now just waiting on the new gasket to arrive - tomorrow, hopefully.

So about this oil leak: tonight I'm going to pull the tank and check to make sure all of the head & cylinder bolts are properly torqued, and clean up the top part of the motor while I'm there. Then once I get this side cover put back on, I plan on riding the bike over to the car wash and cleaning the motor up really well. There's a good bit of oil on the carb, battery box etc that just blew back while I was riding it this past weekend as well. Hopefully I'll be able to get a sense of where it's actually leaking from on the ride back to my house. It doesn't seem to be coming from the valve adjustment covers or the valve cover. That leaves the head gasket (or the base gasket, but I doubt it's that).

I've already ordered a top end gasket set.. hopefully the correct one. If we have to, I'll take the motor out and take the top end apart to replace the gaskets. Rings are $30+ and I don't think we can afford them, unless we sell some more parts. BTW - we've already made about $130 off parts from the parts bike, which is how we've been affording all of these other parts we've had to buy.

Tugboat · « **Reply #101 on:** April 23, 2014, 02:21:32 PM »

I'm almost 100% sure that our major oil leak is coming from the head gasket. Oddly enough, there is no gasket for the rocker cover(!) though I don't see any oil around there. Base gasket also doesn't seem to be the culprit - which leaves the head gasket. I'll know more tonight after I'm able to put the RH side cover back on & ride this thing over to the car wash & clean it off really well.

So the question, then, is this: do we live with the oil leak, knowing that we'll have to stop & put oil in the bike around every 80 miles or so? Is it safe to have that much oil blowing all over everything? Probably not... We could give some sort of stop-leak a shot - and even though I've been running some of that stuff in my KZ400 motor for over 2500 miles now, I'm reluctant to use it here. I'd never considered the wet clutch thing; and those tiny oil passages........

Or, do we open the can of worms that is a top-end rebuild? Well, not a rebuild per se, but tearing down the top end to replace the gaskets. I have a gasket set that should be here by the weekend. Potential pitfalls that I see: discovering a broken cam chain tensioner/breaking it; breaking a ring putting the piston back on; discovering some ham-fisted gouging of the mating surfaces that cause this leak in the first place and you can't really do anything about; going to the trouble & still having sh*^^y compression because it needs to be bored out & piston/rings replaced...

At this point we can't afford a new ring set (@ $35+) so this whole operation would be to hopefully stop the oil leak and maybe gain a tiny bit of compression if the problem ends up being a compromised head gasket. So is it worth it? The devil you know....

mcswny · « **Reply #102 on:** April 23, 2014, 02:29:50 PM »

I cant remember if you've tried, but what about trying a retorque of the head first? Or is it an out of frame job, and might as well go the whole 9 yards?

Tugboat · « **Reply #103 on:** April 23, 2014, 03:01:26 PM »

I'll double-check that before I ride it over to the car wash tonight & see what that does.. not sure I can get to all of them with the motor on the bike.

mcswny · « **Reply #104 on:** April 23, 2014, 03:03:15 PM »

Quote from: Tugboat on April 23, 2014, 03:01:26 PM

I'll double-check that before I ride it over to the car wash tonight & see what that does.. not sure I can get to all of them with the motor on the bike.

Yeah I vaguely remember you saying or asking if it was a engine in or out job. Would be amazing if it was just a re torque, but since when have I been an optimist when it comes to 30-40 year old motorcycles.

grcamna2 · « **Reply #105 on:** April 23, 2014, 04:28:07 PM »

How do the rules work again ? The $500 challenge means $ coming out of your pocket can't exceed $500 for the complete project ? What if someone donated parts to you ?
I don't have any XL250 parts otherwise I'd sponsor them to you...

Tugboat · « **Reply #106 on:** April 24, 2014, 08:40:54 AM »

LOL - thanks man. Donated parts count towards the total though - stuff is worth what it's actually worth. Same with "donated" labor. But yeah, it all has to net out to less than $500.

A couple bits o' possible good news here:

First, we're running rich but the plug isn't oily like I thought it would be.

Second, last night I cleaned the motor really well and, after running it around the block a couple of times, determined that the leak is coming from the valve cover. Interesting that there's not a gasket there (stock config)... I assume Honda didn't think there would be a need for one. So what would cause it to leak here? There is a small bit of pitting on the mating surface of the head (under the black stuff that I cleaned off), but the cover is fine.

To the right of the cover is a small amount of silicone I removed from around the edges. Not sure if that was stock or if somebody's been in here.

So my plan, unless anyone else has a better idea, is just to spread a thin layer of RTV on the cover, let it cure, and then reinstall the cover. That sound right?

Tugboat · « **Reply #107 on:** April 24, 2014, 08:45:08 AM »

I don't think this is a stock cam sprocket?

Far as I can tell, this would be stock...

Some pitting on the cam lobes

Writing in the points cavity, near where the points shaft would be.

Bonus pics

mcswny · « **Reply #108 on:** April 24, 2014, 09:31:40 AM »

OH! You were able to stay in frame, now isn't that convenient!

Do you think you're going to go down to the head gasket and rings or just hope the sealant on the valve cover will do the trick?

Tugboat · « **Reply #109 on:** April 24, 2014, 09:49:48 AM »

Sealing up the valve cover only. Rest would require engine removal. And from what I can tell, it's not leaking from anywhere else on the top end, so hopefully this will do it.

Can anybody recommend a gasket maker? I have black RTV, but others have suggested HiTemp Hondabond, or Permatex's Right Stuff...

grcamna2 · « **Reply #110 on:** April 24, 2014, 10:22:23 AM »

Tug,
I think you need to use Hondabond/Yamahabond,etc. type case sealer,the kind you use to seal the lower end cases;I'd stay away from any silicone sealer. Just prep and seal just like you would the bottom end crankcases.

Tugboat · « **Reply #111 on:** April 28, 2014, 02:36:41 PM »

Race day is only 5 days away.

I let the Hondabond HT set up for 3 days per the instructions, and was able to get the bike out for a test run this past weekend. Mixed results: there is no more leak from the valve cover; after the first 35-mile loop I checked the oil and it was down a half-quart - added oil; after the 2nd 35-mile loop, oil is still full. Not sure if it's sealing up once the motor is warm or what - I had to head straight home after the 2nd loop to avoid a huge storm.

Regardless, the plan is to stop after the first 40 or 50 miles & check the oil there; then again at the 80-90-mile mark when we refuel the first time. If it doesn't seem to be losing oil anymore then I'm tempted to just run it the 80-90 miles that I get w/ each tank of gas. However, I AM worried about it; and if we did lose oil and ran it like that for an extended period we'd be toast. So the smart move may be to just pull over after about every 40 miles and check it really quick. You can do it while seated on the bike.

Other results: I ran the bike slower this time (~60-65mph) in an effort to get a little better fuel economy and to try to find the "sweet spot" for power in 5th gear. That seems to do it. If you go below 60 you seriously lack power in 5th when going up hills; and even though the bike will do 75+, since the motor's worn-out I think it's better to opt for less stress on the engine. Also to that end, I think we're going to run some thicker oil.

We're supposed to have some terrible storms here in TN for the next couple of days, so the next opportunity to get the bike out will be Wednesday night. I'm the only team member to have ridden the bike for any real length of time and on the interstate; hopefully when the other guys do their test runs they don't blow the damn thing up!

Nothing else to do mechanically: either it works at this point or it doesn't. I'll double-check all bolts to make sure they're properly torqued, and I'll probably install a small windshield to help with the wind.

mcswny · « **Reply #112 on:** April 28, 2014, 02:40:16 PM »

Good luck! Excited to here about the results!!!

grcamna2 · « **Reply #113 on:** April 28, 2014, 03:27:44 PM »

That old XL never had it So GOOD

Terry in Australia · « **Reply #114 on:** April 28, 2014, 05:15:10 PM »

I'd use an oil additive like Morey's or Lucas in your engine mate. That cam looked pretty bad, so to keep it running an oil stabiliser that will stick to the lobes of that cam and provide a little extra protection to the rest of your engine under sustained WOT operation is good insurance, IMHO. Cheers, Terry.

mcswny · « **Reply #115 on:** May 05, 2014, 11:38:33 AM »

WELL?!? how'd it go??

Tugboat · « **Reply #116 on:** May 06, 2014, 10:28:40 AM »

The long saga finally comes to a close!

This whole thing began with the question: how many miles can we put on a 400-cc-or-less bike in 24 hours for less than $500?

The answer: zero.

After a couple of team members were able to take the XL250 out for a test run in the days leading up to the big event, we changed the oil, hoping that some fresh 20w-50 would help hold this thing together for the next 24 hours. That stuff looked like liquid graphite, and only had ~60 miles on it. And here is our oil filter:

We wrapped some oil absorbing pads around where we thought oil was likely to leak from, double-checked tire pressure and the torque of all the bolts on the bike, and prayed for longevity.

The morning of the event, all teams were to do a 20-mile run so we could factor in differences in odometer accuracy.

Here I am, ready to go

Our factor was 0.9796 – meaning that for every 100 miles our odometer showed, we’d actually gone 97.96. Bike ran okay on the interstate once you finally got up to speed but it felt really weak; and by the time we got off to turn around and head back, our bike died at the light.. never to be restarted.

10.9 miles for the day; but we didn’t even get to leave the official starting line.

I had been really concerned with our safety, not wanting the top-end to lock up or anything. I posted a thread on the SOHC/4 Bikes forum, asking about what would happened if a motor with bad cam journals ran until it didn’t – and the answers I got is exactly what happened. Between super-low compression and worn cam journals, the motor just didn’t have it anymore. So it goes.

Results:
Doofs Wreck Machine’s 1981 CM400E, bought for $250, did 1,678 miles, and was the winner.

Nashville Motorcycle Collective’s Kawi 250 Ninja, bought for $380, did 1,584 miles.

Team Rust’s 1977 Kawi KZ400 “Klinger”, bought for $400, did 691 miles and locked up the motor while blasting down the interstate at 5am with no headlight. Way to keep the shiny-side up y’all!

The Screwdrivers’ Honda Elite 150, bought for $250, did 1,064 miles.

Ram Jam (us) bought our 1976 Honda Xl250, along with a parts bike, for $300. Sold $140 worth of parts, final tally $459 spent. Zero miles. We gave this trophy to ourselves because it had an XL250 on the top.

@Spanner1 doing some judging

Other event photos here
https://www.flickr.com/photos/hancockadvertising/sets/72157644088001460/] [url]https://www.flickr.com/photos/hancockadvertising/sets/72157644088001460/[/url]

DustyRags · « **Reply #117 on:** May 06, 2014, 11:07:16 AM »

Oh no! Black flagged in the warmup!

Still, a great story, and now I really want to try the same thing out here. Gonna be harder in the Bay Area... $500 bikes don't tend to move much around here.

mcswny · « **Reply #118 on:** May 06, 2014, 11:09:13 AM »

Yeah still definitely fun to follow though.

Love the concept, same as above though, almost impossible in Brooklyn.

You going to keep and rebuild it?

News:

Author Topic: The $500 Challenge (Read 19834 times)