January 2011 15

I can’t seem to find one anywhere. Do you have one?

I don’t have an XS400 repair manual right now. I do have the factory parts fiche diagrams which I am uploading presently (I’m in Mexico so the upstream is a bit slow). I’ll see if I can’t dig up that manual for you. I do have about 50 new manuals in queue to get uploaded but the XS400 isn’t in that mix. Give me a few days and I’ll ask around.

I live outside of Philly and am looking for someone to either help me restore or do the whole job on a 1971 Bonnie & a 1969 matchless that are in “barn” condition. I would like to get them rideable not show bikes.

Note from Reader:
Hope this response will still help the owner. There is a shop in Philadelphia called The Spare Parts Co. located at 406 Vine St (4th and Vine). They do a lot of Moto Guzzi’s and BMW’s but are fairly knowledgeable about Euro bikes. They could probably point you in the right direction if they can’t help you. Phone # is 215.922.2214.

I’ve dealt with these guys before because I wanted them to rebuild an engine for a ’78 BMW R100/7 that I have. Never got around to stripping the bike though.

Trivia fact:
If anyone has ever read the book by Melissa Holbrook Pierson (The Perfect Machine), this is the same shop that she picked up her Moto Guzzi from.

My Response:
Thanks for the post, and for the book recommendation. I’m going to give it a look!

Does your R100/7 need a complete tear down? Or just a top end? I did a conversion on an R80/7 not too long ago and bumped it up with 900 pistons. Sweet little bike

Hi Evan.

I think the R100/7 needs a top end minimum but my thinking was that if I was going to remove the engine anyway, why not see what else needs done? I was hearing this tapping noise from the right cylinder and it was really bugging me. I checked the valves and they seemed ok but I am by no means an expert on this stuff.
Unfortunately, it’s still sitting under a tarp as I’ve been spending most of my time working on an 85 Honda CB700SC. I’m having vacuum problems I think on the inline carbs and I can’t figure it out. I have a feeling the intake hoses aren’t tightened properly because they look off. I had a hell of a time getting them to meet up and tighten the clamps. Any suggestions would be welcome. I am going to take them off again anyway to do the boiling trick you wrote about.

Glad to see that you made it through the cow incident down in Mexico ok. Safe travels.

Oh and thanks for putting this site together!

Thanks for the update.

Airheads will make a tapping sound when the valves are loose. As they say, loose valves are happy valves. But if you checked them and they’re in spec then they may not be the issue (unless they’re worn out). How many miles are on the motor? What does the compression look like?. It could be a little bit of piston slap.

If you suspect your vacuum hoses they I would just replace them. You can get hose at home depot that will work. You shouldn’t actually need the clamps at all to make the hoses seal. The clamps are just so the hoses don’t fall off. What is the issue you’re having?

I’m definitely going to check out that book- Title: the Perfect Vehicle

hey bro am building that bobber out of my yamaha xs850 triple,removed the headlight gonna put a diffrent one on took the turn signals off front and backand tail light off all torn down to cut the frame.problem I am having is before I cut it up I am stumped on how to simply wire it.just want the new headlight,l.e.d.turn signals small ones,tail light…Here is the problem,took the headlight off the wholt wireing harness is routed in theregoes down to everything electrical…was wondering if I should tear those harnesses out and run new wire to everything.I am lost ,as you can see lol.was hopeing you could suggest what to do or direct me to a video or some kind of book…Damn electrical is my only problem on creating this amazing ride appreciate any help,I know you the man to help me…thanks bro…
Pete

Hi Pete – glad you’re making some headway on the bike.

If you’re just looking to trim out all the unneeded wires I generally like to carefully cut the black sheaths off of the wiring harness so all wires are exposed. Then you can easily just trace each wire by hand and snip it off.

Something like this.

Hey there
I did an oil change then after about 2 miles i reset the trip meter and now the speedometer is pegged at zero.  Did it just crap out or is there something funny about these older honda speedos that I should know?
Thanks again

You can tell very easily if the issue is the speedometer itself or the cable. Unscrew the cable from the back of the speedometer and see if the inner cable spins when you roll the bike forward. If the cable still spins, then the speedometer is the issue, if the cable doesn’t spin then it is broken and needs replacing. Old cables break regularly. It’s an easy fix.

Need to know if you can get me a gear assembaly pinion for 1982 honda ft 500? If not, do you know if another model fits this bike? Having hard time and getting bike running is dream come true. Thank you verry much.

That’s going to be a tough part to find anywhere but used. You might need to buy an entire used motor to dig one up. How bad is yours chewed up? Possibly repairable?

Hey there
I have been rehabilitating a 1982 Honda Nighthawk CB450SC.  It was having serious hesitation issues between 3-4 k rpm so I did the “radioshack washer”* carb fix to lift and stiffen the needles.  THe hesitation went away and the bike rides wonderfully accept right before I need to downshift and the bike is under load.  Under these conditions, the rpm’s will suddenly jump from 3k to around 4.5k with NO increase in power.  It is almost like the clutch is slipping.  The clutch seems sound in every other area though, it has never slipped on me otherwise.  I have only experienced this issue while riding in 25-40 degree weather because I only bought this bike in late Nov. and havent had the chance to ride it in nice weather.  This problem is relatively consistant.
I would love to hear your thoughts and suggestions.
Thanks!

*THis trick involves taking a #4 size RadioShack brand washer and installing it at the base of the carb needles inside the needle housing.  The washers are secure and lift/stiffen the needles.  THis year bike had a TSB for the needles which were inappropriately sized and caused hesitation issues on the 450.

Thanks for the washer tip!! 

For jumping RPM under load – that doesn’t make sense unless the clutch is slipping. If the bike is decelerating and the engine is under load the rpms should never jump, and if the clutch slipped in this situation the RPMs would go down. Perhaps you aren’t clarifying the issue correctly. In 4th gear with the throttle pegged under hard acceleration the clutch doesn’t slip, correct?

Correct, it does not slip.  To clarify further, it seems like the engine is getting  fuel as I accelerate then around 3-4 rpm the it stops accelerating holds constant power then gets a surge of rpm.  There is a 1-2 second delay and then more power comes on.  THanks for the reply, I am quite enjoying your blog and your pictures, especially the HDR’s.

Sounds exactly like hesitation due to poor jetting to me. You said in your first post you cured that issue completely, but sounds like you didn’t. It’s a carburetor issue for sure, jetting seems most likely since you have been adjusting things.

i was wondering im told that rejetiing my carbs on my 77 kz 650 is required cus of upgrades i made does that mean i just have to replace the jets onlty or do all other parts need replacing ex floats valve needles etc

If you put on an aftermarket exhaust or air intake then you likely need to upjet. That means only main and pilot jets. Definitely the main jets, likely the pilot jets as well (but not necessarily).