Topic: CB750 Wet Sump Conversion - Sumpthing

[newday777]

That is a great update !

[Ellz10]

***Update*** Solved ***


So I did end up sending out just the main unit back to BJ to be exchanged. Ended up only costing $66 - I made sure to checkmark that it was a returned item to avoid fees and taxes. Took about 3.5 weeks to get there. However, when I did see that it had arrived, it didn't arrive at his shop, it was dropped off at a collection point (never heard of this). So I emailed him and let him so where it was and he said he knew and that he'd go pick it up. Fast forward an hour or so and come to find out they're telling him that he needs to pay €161 to collect it. They tried saying it wasn't a returned good when I even have my copy of customs paperwork that I filled out when I sent it stating that it was. So obviously he declined, which I would have to, and proceeded to tell me something I DID NOT expect. He said he was going to go ahead and just send me a new unit for all the troubles and everything else. I was and still am blown away by this gesture of goodwill, honestly. You really don't find or meet people that have that level of respect and integrity these days. And like I told him, I will definitely be doing business again in the future. That dude is awesome and has my respect. So if anyone has doubts about his business, him personally or how he treats his customers, let this be a testament to that.

I appreciate that great update  Very good news that the person stands behind his product and has that type of integrity.
I'm interested in hearing how it goes with the replacement. 

It arrived yesterday, only took almost 2.5 weeks this time (really fast!) And boy let me tell ya, this thing is BEAUTIFUL! Super shiny, no debris and absolutely magnificent. I'm even more stoked now to watch it function!

That is a great update !

Absolutely. It's sad that we live in a world these days where these types of people are so far and few between, but it let's me know not to give up hope - there are still genuinely good people!

[gschuld]

Excellent.  I’ve been impressed by Bert Jan myself.

George

[wannabridin]

Wow!  What a great update!!  Can't wait to see more pics!!

[Bert Jan]

Since this topic seems to be an important reference for those interested in the kit, i'd figured i'd post the 4 product video's here as well.

Intro

What's in the box

Tools you'll need

In the workshop

[Ellz10]

I just received my sump thing. It looks like a great quality part. Just a couple of things...there are no instructions in the installation manual for priming the pump as it would be very difficult to prime using the typical "pump in a bucket of oil" method. Second, the area in the sump thing that has been machined away to allow clearance for the drive gear on the pump looks a little small...like maybe the gear could contact the sump thing if the gear walks out a little. Thoughts anyone?

I followed the instructions you can download from the sumpthing website to attach the oil pump to the sumpthing.

You NEED to prime the pump again, and it is difficult because now the oil pump is attached and built around the sumpthing.

I took the whole assembly, bought a tub just big enough to fit the whole assembly and bought 5 quarts of oil to completely sumbmerge the whole thing. Primed it as you normally would by spinning the gear, then installed on the bike. (its a messy job, have lots of towels handy) After installation wipe off the oil on the outside with some brake cleaner.

Then I poured 3 quarts of the oil through a valve cover to fill the sumpthing, and saved the extra 2 quarts of oil for a future oil change.

Just run it. It is a quality piece, I havent had any reason to believe the gear was hitting any part of the sump

One thing I have also found: on most of these pumps the thin paper gasket in between the pump and its baseplate has broken down and doesn't seal real well. This reduces the pickup suction by a surprising amount! Once it gets wetted and oil is keeping it wet, it will have suction, but not as much as if you swap out the thin gasket for the new one.

I concur with this, 100%. I used the paper thin gasket provided and it leaked before the bike was even started. I went ahead and ordered 2 Cometic oil pan gaskets. Installing today, shouldn't have any more problems.

Also, re-priming the pump today - its gunna be SO much messy fun.. NOT!  🤣

[Ellz10]

Solved!

Took apart, re-primed the pump and got pressure after a nice long crank with the starter. Just takes a bit longer.

FYI, I have even better pressure with the sumpthing!

How long did you crank the starter for continuously?

[Bert Jan]

I just received my sump thing. It looks like a great quality part. Just a couple of things...there are no instructions in the installation manual for priming the pump as it would be very difficult to prime using the typical "pump in a bucket of oil" method. Second, the area in the sump thing that has been machined away to allow clearance for the drive gear on the pump looks a little small...like maybe the gear could contact the sump thing if the gear walks out a little. Thoughts anyone?

I followed the instructions you can download from the sumpthing website to attach the oil pump to the sumpthing.

You NEED to prime the pump again, and it is difficult because now the oil pump is attached and built around the sumpthing.

I took the whole assembly, bought a tub just big enough to fit the whole assembly and bought 5 quarts of oil to completely sumbmerge the whole thing. Primed it as you normally would by spinning the gear, then installed on the bike. (its a messy job, have lots of towels handy) After installation wipe off the oil on the outside with some brake cleaner.

Then I poured 3 quarts of the oil through a valve cover to fill the sumpthing, and saved the extra 2 quarts of oil for a future oil change.

Just run it. It is a quality piece, I havent had any reason to believe the gear was hitting any part of the sump

One thing I have also found: on most of these pumps the thin paper gasket in between the pump and its baseplate has broken down and doesn't seal real well. This reduces the pickup suction by a surprising amount! Once it gets wetted and oil is keeping it wet, it will have suction, but not as much as if you swap out the thin gasket for the new one.

I concur with this, 100%. I used the paper thin gasket provided and it leaked before the bike was even started. I went ahead and ordered 2 Cometic oil pan gaskets. Installing today, shouldn't have any more problems.

Also, re-priming the pump today - its gunna be SO much messy fun.. NOT!  🤣

What gasket leaked and why? Please explain as good as possible. I’m constantly trying to improve the kit and the information from you guys helps loads. Thanks!

[Bert Jan]

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.

[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.

[calj737]

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?

[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.

[calj737]

Yes, I did mean to say the head from the stick motor is removable with the frame kit. Every 750 motor I’ve pulled assembled was awfully tight with the stick oil pan on. As I said, I’m not sure a kit will allow sufficient room to pull the assembled motor with the Sumpthing. Probably a question for Bert…

[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.