Topics

1975 CB550F in near mint condition!

My son took his RD to the local car/bike show, he was the only non-cruiser there, but caught more interest than all the rest!

I'm looking for possible causes why a basket case DS7 isn't getting fuel into the combustion chambers.

The carbs are cleaned and seem to check out fine, the floats are adjusted, bowls are full, pilot jet checked for obstructions, and I raised the needle all the way up just to help get fuel moving.

Compression isn't great at just over 100psi, but should be enough to push air around.

The plugs are bone dry after kicking it over. 

When placing my hand(s) over the exhaust (no pipes on yet) and back of the carb it actually feels like more air is being exhausted rear-ward through the carbs than forward out of the exhaust.  I also get a little fuel spatter on the hand behind the carb, and none out of the exhaust.

This bike is a mess, the PO was a severe hack and gave up halfway through destroying this thing. 

He said he put in some new(er?) pistons (no boring was done it sounds like), so I am thinking he possibly installed some incorrect  pistons that are blocking the transfer ports?  That's the only reason I can think of for this, but please advise if you've got a different idea!

The elusive zero main jet!

I enjoy working on RD's, but it's a luxury to have a push-button bike to ride as well.  I couldn't pass this 300 up, only 15.x hours on the clock.

https://m.facebook.com/marketplace/item/441768410141477/?referralSurface=messenger_lightspeed_banner

I have informed it that's it an R5, but he informed me in return that he was an RD expert!

I can't find a 90/90-18 RoadRider in stock anywhere, but I can find a 2.75x18 Streetrunner, has anyone used one of those?  Or should I go with the Bridgestone BT45?

Building my sons bike he wants to run SS lines and went to both them up last night, I discovered I had the wrong banjo bolt (should be 10x1.0 for caliper), and I found in th tech section that I need to remove the flare or olive fitting inside the caliper to allow room for the banjo bolt.

Question is, how do I remove that fitting inside the caliper?   I may be as easy as pulling on it, but figured I'd ask before I make more work for myself.

This is a video the previous owner had posted.  I'm not crazy about the tracker styling I don't think but it looks to make plenty of power (PO had it dyno'd at 86rwhp). 

https://chicago.craigslist.org/wcl/mcy/d/dekalb-1987-yamaha-ysr-50/7013805397.html

https://chicago.craigslist.org/sox/mcy/d/hammond-yamaha-dt-50-parts-motor/7004117804.html

I am trying to use a Yamaha Radian swingarm on an RD400 frame for a scrambler-type build.  It mounts fine up front and would have a lot of room for a Knobby-ish tire, but.....   The issue i have is that it has chain adjusters that are internal and they won't allow for the threaded portion of the brake caliper bracket insert to pass through the swingarm and be bolted from the outside like a stock 400 swingarm does.  I could cut that threaded insert shorter and it would all fit, and still run the brake arm to keep the caliper bracket from spinning, but would that be ok?

I just ordered a Vapor Honing Technologies vapor blaster.  Is anyone else here using one of these?  It should be great for carbs, fork lowers, engine cases, side covers, his, etc.  The only drawback is a 3-4 week wait for the build time!

So, I picked up what's titled as a 73 rd250, and it has a drum front end.  Did all 250s have drums, and if not when did they switch to disc?
Thanks

If anyone needs an rd60 seat, can't imagine you stumble across them for sale often:

https://minneapolis.craigslist.org/ank/mpo/d/cambridge-motorcycle-seat-rd60-yamaha/6870094115.html

https://minneapolis.craigslist.org/hnp/mcy/d/le-center-vintage-yamaha-rd350/6862445555.html