1980 Honda XR250, Back on the Boards

[OJ]

Hey guys. Took a break off the boards, sold my CB378 because I needed cash to finish my trailer sauna, but realized I needed a bike to wrench on. FFWD to last week, I found a 1980 Honda XR250 locally on kijiji and when I went to pick it up, turned out the seller had another bike in pieces. So now I'm a new owner of two 1980 Honda XR250's. One is pretty much complete, with surprisingly clean camshaft journals, but I am still waiting for a new cam chain as the old one is stretched and I figured I'll install a new one before putting it back together.

Not sure how active I'll be here, but I want to get the bike running to hit some trails and dirt/gravel roads. This will not be one of those ave inspiring fabrication masterpiece stories.

 

[adventurco]

Welcome back bud. Looks like a good buy, the inside of that head looks brand spanking new. Carry on.

 

[Hurco550]

I want to get the bike running to hit some trails and dirt/gravel roads. This will not be one of those ave inspiring fabrication masterpiece stories.

Welcome back! And that's ok. I for one really enjoy seeing pics of where these bikes take people just as much as seeing the bike being built sometimes! Top end looks great!

 

[OJ]

Got the new cam chain installled last night. The old chain was kinda weird with lots of stiff links. Anyway, she didn’t start as there’s no spark. Did meter everything all the way to the coil and everything seems to be OK but ther’s no spark. New coil didn’t fix it, but there might be issues with the resistor cap that I need to replace.

Or a question at this point. What kind of voltage is healthy when I kick it over. I metered from the generator and pulser and then where wires plug into the coil.

The wiring job on this bike is not the cleanest, so I might end up redoing the harness.

 

[OJ]

Well dammit! All the continuity seems to meter to the spec, but I’m still missing spark. When giving a good kick, my meter can’t get the spike coming out of the CDI, but highest I managed to meter was 9-10V. The coils meters per spec, wire is new, resistor cap is new and plug is new. So what kind of black magic is going on here?

 

[OJ]

New ”development” here. Lesson 1, never ever trust the existing wiring if there’s issues. My wiring was messed up, but got it fixed. So now I get good 35-40V from CDI just using my hand to kick. My old coils are NFG, but I installed a new emgo coil on. This Emgo coil has bang on primary, but secondary is only 4.9 kilo ohm. I get virtually no power from the coil so I think it’s safe to say this Emgo thing is no good for this bike. Can anybody kindly point me to a vendor where I could find 6V, 0.2-0.8 ohm primary and 8-15 kilo ohm secondary coil?

 

[irk miller]

You should be running an AC coil on this bike, not a DC coil. Are you sure you have the right coil?

 

[OJ]

I think the emgo coil is DC. It’s an emgo 24-71536 coil that is supposed to work on XR and CR, but are newer models DC? I guess I need to find an AC coil somewhere.

 

[irk miller]

There's no battery and power to the lights are run directly off the alternator. That's the white/yellow wire in your handlebar switch. That's usually indicative, especially with dirt bikes, of an AC system. But, as you say, fitment claims to be correct for your bike.

 

[OJ]

Back from the lake, and buddy had a spare AC coil with close-ish spec so I’ll get to give another try tomorrow. Having an old motorcycle enthusiast friend across the street has some benefits.

 

[OJ]

Not the most exciting thread here, but the new coil did not improve the situation. I did meter at the resistor cap and do get only 40-45V, so obviously not enough to spark. I’ve checked everything else at least twice, so I may have to order a new coil. I did find OEM coil for this one, and even while pricey, might be the easiest way to go.

 

[OJ]

F YEAH! She’s alive!

Not sure what happened, I changed nothing, but when I kicked it ”one more time” I got a big fat blue spark. So tank on, couple of kicks and she sprung to life. Of course it’s not all smooth sailing as the shifter seal spits oil.

 

[OJ]

Feel like a kid again ripping up and down the backlane. I feel sorry for my neighbors as I built a trailer sauna in the spring, it’s now parked on my backyard, and now I’m tormenting the neighborhood with another old bike. My weirdo/hipster/hippie score is not improving

 

[Brodie]

Good to hear. Might be a loose connection somewhere.

 

[OJ]

Managed to get a ride in last night before it got too dark. Bike runs OK, but there is a minor oil leak at the valve cover and bike ran bit lean choking when opening the throttle from slower speed and backfiring a little. So nothing too severe. It’s fast enough that I didn’t have balls/skill to run through the gears on the trails. Of course I didn’t take photos as I was in a bit of a rush before it got dark.

I’m not 100% confident with the air filter/box fit. It’s almost like it’s too short and not angled enough to reach the carb. Would suck to get a leak on the trails and get something sucked in. Is there any pod filters that would work well on this or is it the old ”stock filter is the only way to go”?

 

[Brodie]

You could get a pod to work. But as always on an off-road machine the stock airbox is the way to go. Nothing stopping you from using a higher quality filter in their though. Stock box should have a high intake to help prevent water or dust being sucked in.