Topic: Replacing wheels and exhaust pipes for Honda CB750

[kyle750]

Looking closer at the exhaust this morning in the full sun and noticed 2 small holes in the Number 4 exhaust.

[newday777]

Also just to confirm.  The number 2 pipe is the second pipe starting from the left.  Number 1 is left top (with heat shield), Number 2 is left bottom, Number 3 is right bottom, Number 4 is right top (with heat shield)

Correct

[newday777]

Looking closer at the exhaust this morning in the full sun and noticed 2 small holes in the Number 4 exhaust.

You could get someone to tig weld those holes to get some life out of them.

[newday777]

If that's your #2 pipe I don't see any rust

[kyle750]

Sorry mate the photo is the Yamiya #2.  I will take a photo now of my #2 - it is shocking and ugly!

[kyle750]

Welcome to Thailand

[newday777]

Sorry mate the photo is the Yamiya #2.  I will take a photo now of my #2 - it is shocking and ugly!

👍

[kyle750]

Cleaning and polishing test this morning

Applied WD-40 to a very small area and let it work its way into the accumulated oxidation/haze and surface rust and then knocked it down with 0000 steel wool.  Oxidation and most surface rust came right out.  Wiped down and then applied a thin layer of autosol, rubbed it in, and then buffed it out.  The transformation is hard-to-believe.  When viewed up close you can see where the rust has pitted the metal but from a distance the overall look of the chrome  is nice, even, and shiney.  Far from perfect but old chromed metal will never look like new again. Still undecided if the pipes are worth saving and keeping?

5 minutes working on the back end of the Number 4 pipe

[MauiK3]

On Maui, stock spokes look very bad, very quickly. I imagine it's the same or worse there. Stainless is pretty easy to keep up and will save you lots of labor keeping them looking good.

[Stev-o]

On Maui, stock spokes look very bad, very quickly. I imagine it's the same or worse there. Stainless is pretty easy to keep up and will save you lots of labor keeping them looking good.

+1....I've always sprung for stainless spokes, worth the extra cost in my opinion

[kyle750]

Stainless spokes will certainly be less maintenance and not corrode like chromed steel spokes  but stainless spokes will not match the chromed steel wheels. I would think the duller more matte finish stainless would look odd and slightly out of place.   I could see how stainless or zinc plated spokes would work well with aluminum wheels. 

[newday777]

Stainless spokes will certainly be less maintenance and not corrode like chromed steel spokes  but stainless spokes will not match the chromed steel wheels. I would think the duller more matte finish stainless would look odd and slightly out of place.   I could see how stainless or zinc plated spokes would work well with aluminum wheels.

Original spokes are zinc plated

[kyle750]

Original spokes are zinc plated

Thanks.  I did not know the original spokes were zinc plated.  I mistakenly thought they were chrome plated steel. The spokes on my CB750 look like skewered rust kebabs

I ordered the Yamiya chrome steel spokes but I have not even started on the wheels as I am waiting for replacement fenders.   At this point it would be very easy to change and order and install zinc or stainless??

[BenelliSEI]

Cleaning and polishing test this morning

Applied WD-40 to a very small area and let it work its way into the accumulated oxidation/haze and surface rust and then knocked it down with 0000 steel wool.  Oxidation and most surface rust came right out.  Wiped down and then applied a thin layer of autosol, rubbed it in, and then buffed it out.  The transformation is hard-to-believe.  When viewed up close you can see where the rust has pitted the metal but from a distance the overall look of the chrome  is nice, even, and shiney.  Far from perfect but old chromed metal will never look like new again. Still undecided if the pipes are worth saving and keeping?

5 minutes working on the back end of the Number 4 pipe

If there are no rot holes in your pipes they are worth saving! They will look great!

[RAFster122s]

Polished zinc can develop a sheen but it oxidizes quicker than an aluminum or other common metals... Bright zinc and clear coated bright zinc holds up well until the clear coating it is give passivating it goes, then it dulls quickly.

[Don R]

 In a corrosive climate, I'd go with the Stainless spokes.
  I had a pair of 16" rear rims on Honda hubs, I needed one 2-hole hub for a restoration and took them both apart. I re-assembled a nice 16" rim re-using the stainless-steel spokes and hub from an old and badly rusted rim, they came apart, wiped clean and re-laced onto a nice 16" rim and still look like new.

[kyle750]

On my Honda CRF250L I have stock aluminum DID wheels and I believe zinc plated spokes (bright when new).  The bike is now over 12 years old living near the ocean in a hot and humid climate with over 60km riden in constant high humidity and sometimes in torrential downpours (I actually really enjoy riding in the rain).  I almost never wash the bike and the wheels still look like new but the spokes have turned to a dark grey color - not rusted but heavily oxidized.

I finished cleaning and polishing pipe #4 yesterday and I am totally shocked at the transformation.  When compared to the #3 pipe sitting right below it looks like a new pipe.  Certainly not perfect but the improvement is dramatic.

[kyle750]

I just finished cleaning the #3 pipe.  Of the 4 pipes this pipe is in the best condition.  Heavy oxidation but very little surface rust and only a few small spots of larger rust (no holes). Applied the WD-40 and it immediately cut through and dissolved the thick layer of oxidation and started working on  the rust spots.  Quick run of 0000 steel wool and the chrome is already bright and shiney and I have not even applied the metal polish yet.

I've coated the #1 pipe in WD-40 and I'm going to let it soak in a little longer before I start working on it.  This is moving along much easier and faster than I thought it would and the results are amazing!  Thanks everyone for the encouragement!

As a quick reminder for anyone who is following and is interested -  here is the bike on the 1st day of its arrival   

[kyle750]

I just received a wonderful email from Yamiya in Japan.  Very friendly and he is very interested in the project and generously offered suggestions and recommendations.  I am already a very LOYAL customer and looking forward to ordering more. If the pipe cleaning goes well I will be ordering again very soon.  I am quickly discovering that Honda  CB750 owners are very fortunate as it is a very popular bike so there are lots of readily available parts (both original and reproduction)  and different sources to restore the bikes and get them safely back on the road.   

[kyle750]

Pipe #1 has a number of smaller rust spots near the top seam on both sides.  As this is a top flat surface I am quessing moisture condensed there.  The steel wool does a great job on the surface oxidation but not on the rust spots (the rust spots are much thicker and sit slightly above the surface).  I soaked the rust spots well with WD-40 and then used a small piece of plastic formica about 2mm thick with a straight edge and gently scraped the rust spots and they popped right off.  I believe the WD-40 penetrated and loosened the rust and with the slightest scrape from plastic they were gone.  The transformation of these pipes is amazing . . .  and  I have not polished yet??

[kyle750]

Pipe #3 and #4.  WD-40 only not polished yet (you can see the reflection of my camera in both pipes)  I will be cleaning the front of the pipes tomorrow.

[newday777]

Pipe #3 and #4.  WD-40 only not polished yet (you can see the reflection of my camera in both pipes)  I will be cleaning the front of the pipes tomorrowbackside?

Nice transformation 👌

Did you pull the pipes off the bike so you could get to the backsides?

For any chrome spots that are rusted through the chrome it would be advisable to spray with high heat exhaust paint at a minimum so the rust doesn't come back right away.

Here is a number 2 pipe I repaired with a patch a couple years ago on the backside and painted after. Once back on the bike you didn't see the repair or paint unless you looked closely for it. I used sheet steel I formed over the pipe, but next time I will cut out stainless steel patches as they will polish up when done properly so they show less.

[kyle750]

Nice transformation 👌

Did you pull the pipes off the bike so you could get to the backsides?

For any chrome spots that are rusted through the chrome it would be advisable to spray with high heat exhaust paint at a minimum so the rust doesn't come back right away.

Here is a number 2 pipe I repaired with a patch a couple years ago on the backside and painted after. Once back on the bike you didn't see the repair or paint unless you looked closely for it. I used sheet steel I formed over the pipe, but next time I will cut out stainless steel patches as they will polish up when done properly so they show less.

No I did not pull the pipes off and only cleaned them in place.  The insides were a little tough to get to and I am sure I missed a few areas.  Nice repair work on your #2.   As the #2 and #3 sit  below the upper pipes most of the pipe is not visible.   Right now my pipes are still coated in WD-40 and I will inspect them again in the full sunlight tomorrow.  I am planning on painting the spots that have rusted through after removing the WD-40, cleaning the spots with paint thinner,  and painting them before polishing the rest of the pipes.

[BenelliSEI]

Take some pictures of the “rust through” areas. There are drainage holes on the underside where the head pipes connect to the muffler portion…. Keep those open.
Smaller holes, on the underside where they are not visible?

[kyle750]

After seeing how well the pipes cleaned up I went ahead and purchased the #2 Yamiya no number pipe and also 341 baffle diffusers for my 1,3, and 4 exhaust pipes.  The left heat shield was in rough condition (very scraped and rusted) but the right heat shield is in very good condition.  I purchased 1 exhaust heat shield from a seller on Ebay for $45 shipped (photo attached)

As the #2 pipe is not very visible I am hoping the Yamiya new chrome will look OK with my 50 year old chrome.  I have no idea why my #2 rusted out so badly.  My #2 pipe needs to be removed and given a proper burial in a landfill