Topic: CB750 Wet Sump Conversion - Sumpthing

[Floshenbarnical]

Sorry for resurrecting this topic. I’m just trying to keep stuff as up-to-date as possible.
I’m currently (November 16/17/18 2023) running a Black Friday Discount on the kit.
I’ve reduced the price in the webshop so no need for fancy discount codes or anything.
Normal price is 499,- EU, now only 439,- EU which should basicly cover worldwide free shipping.

oi oi saveloy nice to see you posting here again, i just bought one as we discussed on insta.

Now I just have to figure out how to get an exhaust to fix around it. I was going to get a new one regardless because mine looks like #$%*, so it's just an extra step.

[HondaMan]

I think this is both a clever and well-designed conversion, if you want an oil-tank-less CB750. Takes some perseverance to assemble in the frame (for old guys like me), but it is made well.

[Floshenbarnical]

I think this is both a clever and well-designed conversion, if you want an oil-tank-less CB750. Takes some perseverance to assemble in the frame (for old guys like me), but it is made well.

I have to split the bottom end to solve a persistent oil seep so I was considering mounting it while the motor is upside-down on the bench, but I've seen that the motor is hard enough to get in and out of the frame already without a 50mm extension on the bottom.

Now I just have to convince someone to help me wrestle the bloody thing out of the frame.

[HondaMan]

I think this is both a clever and well-designed conversion, if you want an oil-tank-less CB750. Takes some perseverance to assemble in the frame (for old guys like me), but it is made well.

I have to split the bottom end to solve a persistent oil seep so I was considering mounting it while the motor is upside-down on the bench, but I've seen that the motor is hard enough to get in and out of the frame already without a 50mm extension on the bottom.

Now I just have to convince someone to help me wrestle the bloody thing out of the frame.

I sure don't see a way around assembling the Sump Thing onto the engine after the engine is in the frame?

[Floshenbarnical]

I think this is both a clever and well-designed conversion, if you want an oil-tank-less CB750. Takes some perseverance to assemble in the frame (for old guys like me), but it is made well.

I have to split the bottom end to solve a persistent oil seep so I was considering mounting it while the motor is upside-down on the bench, but I've seen that the motor is hard enough to get in and out of the frame already without a 50mm extension on the bottom.

Now I just have to convince someone to help me wrestle the bloody thing out of the frame.

I sure don't see a way around assembling the Sump Thing onto the engine after the engine is in the frame?

I think you're absolutely right. I had watched a video of a bloke installing it off the frame, but I think it was an instructional video for his channel and it was more convenient to film it w/ the engine out of the frame.

Do frame kits really make it much easier to get the engine in and out? Who has the best one? I know someone here on the forum sells them.

[newday777]

Scottly was the last making the frame kits after Frank (754) passed 😢
I don't know if Scott has any kits left now.
Yes the kit will allow you to install the cases and sumpthing, then install the cylinders and head after when it is in the frame.

[Floshenbarnical]

Scottly was the last making the frame kits after Frank (754) passed 😢
I don't know if Scott has any kits left now.
Yes the kit will allow you to install the cases and sumpthing, then install the cylinders and head after when it is in the frame.

I'm not splitting the cases. I was hoping the kit would make it easier to remove in one solid lump. I'm going to split the bottom end open so I can reseal it. I've got a very minor oil leak somewhere and I hate it.

[newday777]

Scottly was the last making the frame kits after Frank (754) passed 😢
I don't know if Scott has any kits left now.
Yes the kit will allow you to install the cases and sumpthing, then install the cylinders and head after when it is in the frame.

I'm not splitting the cases. I was hoping the kit would make it easier to remove in one solid lump. I'm going to split the bottom end open so I can reseal it. I've got a very minor oil leak somewhere and I hate it.

I didn't say splitting the cases.
It should give enough space for you to get the whole motor in with the sumpthing in.

[newday777]

It should give enough space for you to get the whole motor in with the sumpthing in.

I don't know this to be true. The Sumpthing is 5cm lower than stock. The frame kit allows just enough room to get the stock motor out. The extended oil pan still may not clear as the backbone is unmodified with a frame kit.

My suggestion is to plan to remove the Sumpthing each time and install it after the motor is in the frame. Order and have on hand extra oil seals. How many times do you plan to pull the motor after your "refurbishment" anyway?

You can already get the stock motor out without the frame kit. The frame kit allows the head and cylinders to come off in the frame so there is 5-6 inches extra space.

[Floshenbarnical]

Thanks for the responses everyone. I'm just going to install it while the motor is in the frame, once I've put it back in.

All I'm doing this season is trying to stop that oil leak. I'll probably throughly clean it and enamel it, but that's about it. I was going to have Hondaman take a look at the insides but I'm tight on cash so will try to get that done next year. But I will invest in some extra, good oil seals.

[HondaMan]

I've got a very minor oil leak somewhere and I hate it.

There's 2 places to check for that leak:
1. The countersprocket (chain) oiler adjuster's rubber inside the countershaft is probably a little shrunk from the years, now, so it is over-oiling. When I adjust them these days (if I don't replace the seal inside the shaft) I turn them in all the way to the stop, then backout 1/2 to 3/4 turn. Then it won't drip, and only oils above (roughly) 50 MPH, so keep an eye on the chain.
2. The Neutral Switch. Most of the bikes now have exceeded the 10-year-life epoxy used to seal the switch. While it can be re-sealed without too much work, you can also get a new one from Honda or (sometimes, they go quickly) at PartsNmore. It can just barely be installed with the engine in the frame. If you do this and need a new O-ring, PM me for one: it is size 3x18.

[Bert Jan]

Hi all,

Update about the SumpThing kit.
Production has been upped and we currently have around 20 kits in stock at any given time.

We’ve also managed to get a dealer/reseller in Ontario Canada, Sane Motion Moto. If you’re close to him it might be cheaper to get it from him.

We’re also actively searching for dealers/resellers for the USA (Preferably one west, one centre and one east) and other countries. Please don’t hessitate if you run a (web)shop and want to sell the kits!
Contact me at outsidersmotorcycles@gmail.com - MOQ for dealers is 10pc, color is up to you.

[grcamna2]

Excellent 

[HondaMan]

Hi all,

Update about the SumpThing kit.
Production has been upped and we currently have around 20 kits in stock at any given time.

We’ve also managed to get a dealer/reseller in Ontario Canada, Sane Motion Moto. If you’re close to him it might be cheaper to get it from him.

We’re also actively searching for dealers/resellers for the USA (Preferably one west, one centre and one east) and other countries. Please don’t hessitate if you run a (web)shop and want to sell the kits!
Contact me at outsidersmotorcycles@gmail.com - MOQ for dealers is 10pc, color is up to you.

That's a fine quality kit you've got going! For the show bikes I've built they have been popular and simple enough to install. I made a flat steel (1/4" thick) plate in the shape of the oil pan for protecting the engines (and frames) on the way in - it's a snug fit - and then installed the Sump Thing afterward, not hard to do. Your oil-level window is a nice touch, too.

Back in the 1970s someone was making a similar conversion to yours, but sans window. It was popular with chopper builders back then: they would drop in one of Russ Collins' 1000cc kits and then the tankless conversion, but it held so little oil then that they changed it every 1000 miles (2 quarts was all it held). Yours holds more than that, though, a good thing. AND it can be checked, a great improvement!

[Bert Jan]

That's a fine quality kit you've got going! For the show bikes I've built they have been popular and simple enough to install. I made a flat steel (1/4" thick) plate in the shape of the oil pan for protecting the engines (and frames) on the way in - it's a snug fit - and then installed the Sump Thing afterward, not hard to do. Your oil-level window is a nice touch, too.

Back in the 1970s someone was making a similar conversion to yours, but sans window. It was popular with chopper builders back then: they would drop in one of Russ Collins' 1000cc kits and then the tankless conversion, but it held so little oil then that they changed it every 1000 miles (2 quarts was all it held). Yours holds more than that, though, a good thing. AND it can be checked, a great improvement!

Thanks man! Appreciate it! It’s good to hear that the install process goes smoothly.
Good info about the previous guy who made such a unit. Any more info on that?

[Oddjob]

I am curious as to why a imperial 7/8" spanner was used in the video for tightening up the sight window, I'd have thought you would have been all metric by now, especially as you are in Europe, the home of metric. I doubt I have many imperial sizes left in my toolbox these days and I'm sure that's true of most others. Just wondering if the sight window is metric sized or imperial?

Love the kit BTW, extremely well made by the look of it.

[spotty]

I am curious as to why a imperial 7/8" spanner was used in the video for tightening up the sight window, I'd have thought you would have been all metric by now, especially as you are in Europe, the home of metric. I doubt I have many imperial sizes left in my toolbox these days and I'm sure that's true of most others. Just wondering if the sight window is metric sized or imperial?

Love the kit BTW, extremely well made by the look of it.

i gave away or threw out all my non metric stuff years ago, partly cos i don't need it cluttering up the place and partly so when my mates tell me to buy a harley i can truthfully say the only tools i've got that fit it are hammers