Vintage Dirt Bike Q & A

you got to get that gas tank problem fixed your going to continue to have trouble. there are tank coatings avalible that don't cost to much. kreem is one brand and eastwood sells some. i've used kreem several times with good lasting results, but i have had other people tell me they had problems ! if your going to use a tank coating you must get the tank as clean as possible NO OILS ! good luck. the clark tanks are nice i would like one for my xl200r they are a little spendy though. i can go about 150 mi. on my stock tank thats about far enough on an xl200r. if i need to go more miles i can stap a gallon can on the back. one more thing if you want to make it steet legal at some time a plastic tank may not pass i know in oregon they are a no no.

My dad thinks i should kreem it to. I dont think i'll ever make this one street legal, probably sell it first. If when we get done fixing the petcock, and it still gets clogged, i think i'll go ahead and buy the Clarke or maybe buy this one if it goes for under $150
http://cgi.ebay.com/ebaymotors/HONDA-MR ... ccessories

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Jess,

The 1362X is a universal-fit tank, so it took more effort to mount than the direct-replacement tank on my CR. I drilled a hole through the frame gussets below the steering head for the front through-bolt, then made up a small steel strap from the rear tank mount down to the threaded frame hole under the seat/tank junction (I didn't want a rubber-band rear mount). It took about 2 hours to put in, taking my time.

I also tried mounting it an "easier" way... long story short, I put a small hole in the tank near the front mount, repaired it with Plastic Weld (holding fine for many months now), and ended up getting a spare tank at dealer cost from Clarke just in case. If you decide you can use a new-in-box black 1362X, let me know.

I ended up beating back the rust problem in my original tank, only to end up with a leak around the petcock. The plastic tank has been great.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

hmm you wana PM me how much you will sell it for?

Jess

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

jleeb, this stuff is great & will do several tanks. Our NAPA store carries it. Red Kote
http://www.4secondsflat.com/Fuel_Tank_Sealer.html

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77 MR175, 89 HD Sportster
74 CR125, 00 Kawasaki ZG1000
79 XR185, 56 Cushman Eagle
03 XR650L, 79 Vespa P200E
72 Vespa Super150,
74 HD Z90

Well i got some 1/8" brass tubing yesterday for the petcock snorkel, put it on this morning and filled 'er up with 50/1 and started pushin' in third gear, and then popped the clutch... it will pop of and run for about 20 seconds then die. and will do this just about every time i try any suggestions?

Jess

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Well I know it's been a long time, but I'm back... We built a shop, so now I have a place to work on the MR. I can't get the bike to start, due to no spark... I was wondering if anybody could tell me how many volts DC, are supposed to be coming out of the rectifier? I'm getting 6 - 6.5 AC out of the magneto. and about 4 DC after the rectifier, and nothing after the coil...

Thanks again, Jesse

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Jesse,

When you bought the bike, it was running, correct? What has changed in the ignition system since then? Anything with the kill switch or wiring? I assume you've tried a new plug...

The stator source coil should put out over 200VAC peak-to-peak, in a short spike that most meters cannot read accurately.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Ray,

Yes it was running when I bought it, although it had fuel problems (fixed). no change to the wiring as far as I know. there is no kill switch on the bike. I will be getting new plugs this afternoon, as the Honda shop isn't open on mondays

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Another question. When we test the continuity of the wires coming out of the left crankcase, they ground?? does this mean we have a short somewhere?

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Jesse,


Both stator coils ground to the motor case. You should be able to get a resistance reading from the black/yellow wire to the case, though - at least it will tell you if the source coil is shorted or open.

If you think the rectifier is bad, you can disconnect it and connect the black/yellow and (I believe ) black/white leads together to bypass it - there's another ground wire you can leave connected if you want.

The bike originally had a kill switch. I'd be curious what happened to it, especially since you have no spark.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

Well still not getting a spark, I looked at your wiring diagram on another thread, and found out the black with white stripe, and the green wire coming out at the top of the wiring harness should be wired together, b/c I have no kill switch.... Is this right? Also I'm getting resistance through my spark plug cap. bad cap?

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

That wiring diagram has the kill switch positions labeled backwards, so the black/white wire would remain disconnected with no kill switch. By the way, I would highly recommend the use of a kill switch.

I'm not sure if the MR175 plug cap is a resistor cap, but it might be; if so, it could read anything from 1,000 ohms up to 10,000 ohms (I think about 5,000 ohms would be the most likely). I'm not a big fan of resistor caps on these older ignitions as they reduce power to the gap, and the resistors have been known to fail too.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric

We're pretty certain it's the coil... the plug cap is getting 4300 ohms... is bike bandit cheapest place to buy a new coil?

Thanks for all the help

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-----1975 Honda MR175--------------------------------------1972 Suzuki T500 Titan------------------2003 Honda 250 Rebel

Yamaha XS850
Triumph Bonneville 650

Jesse,

Wow, the coil is still available as OEM - another part kept alive by the 80's FL250 Pilot. I think Babbitt's Online is about $6 cheaper than BikeBandit, and you could always order it through any Honda dealer if you needed it quickly.

Ray

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'74 CR125M (175cc), '75 MR175, '82 RM250Z, '08 YZ250F, '14 Zero FX electric, '14 Zero MX electric, '18 Alta MXR electric