Author Topic: Need help in deciding bike build (Read 3491 times)

Jaroldoe10 · « **on:** April 16, 2020, 02:47:21 PM »

Hello all, hopefully someone can help me before i get myself bound up in a bike build. Let me start off by saying that I am mechanically inclined, have worked on engines before but still have lots to learn. I pick up fast so if you write something here I will research it to get a better understanding and apply it. OK, so I'm looking to build a sohc CB750 chopper. will be purchasing a rolling frame, wiring done myself (unless cheap enough to buy) going to buy an engine and work on it. Time is not an issue, money either, although I don't really want to put 6 or seven grand into it. I guess it doesn't really matter as I want to buy, and work on, each piece one at a time. was going to buy the engine first. i want it to be kickstart, and super easy to work on... so the specific questions would be... Which engine model and year should I go for? should I buy a complete engine or piece together (ie. top end, then bottom end, then carbs, etc. etc) anything up to this point that I should be aware about? if I do buy one piece at a time do the top ends interchange with the bottoms for the most part or do I need to find and exact year/model? I have a thousand more questions to ask but ill leave it there for now. please guys any help is appreciated as I'm excited to start this project... one last one, where would anyone suggest to find new and/or used parts for these motors? lol one more. is the CB750 the best viable option or should I consider others? speed is not a huge factor as much as reliability and ease to work on. thank you

bryanj · « **Reply #1 on:** April 16, 2020, 02:49:45 PM »

If 750 some things dont interchange so complete motor then rebuild as necessary is better way imho.

754 · « **Reply #2 on:** April 16, 2020, 02:52:19 PM »

If you are thinking very fat tire on rear get a 77 or 78 motor.. ..

jakec · « **Reply #3 on:** April 16, 2020, 03:54:11 PM »

it depends on what kind of chopper you're building but I like 500/550 choppers better because the engine is smaller than the 750 so you get more empty space in the frame. if that's what you're going for. The 350, 400, and 550's are just tight little engines and the 750 looks #$%*ing huge in comparison imo.

If I ever grow a pair and build one I would go for this style. I won't put a name to it cause I don't want to argue haha.

https://rawhidecycles.com/products/lucille

jakec · « **Reply #4 on:** April 16, 2020, 03:55:50 PM »

compare that with this build by the same place (still a sick build) and look how big the engine is.

Stev-o · « **Reply #5 on:** April 16, 2020, 05:04:26 PM »

HAve you found a rolling frame that you are going to buy? If no, it may be best to buy a complete bike that needs a restoration, than you will have the majority of parts and restore it as you see fit [I did this with my CR750]

Not this one, but similar price, would be a good value.

https://minneapolis.craigslist.org/ank/mcy/d/honda-cb750-chopper/7103979399.html

Start shopping!

BTW - Honda made over 600,000 [yes six hunder thousand] SOHC 750's, so parts are plentyful and reasonable priced. Most of us here have many spares we sell to other members for very reasonable prices, I have been given parts free and have given some out.

754 · « **Reply #6 on:** April 16, 2020, 05:27:22 PM »

Jake, high mounting a tank, looks like more space around the motor, so your pic is off a bit.
750 motors are cleaner looking, and when you can see more if your motor in a custom frame it matters, and you can build them much bigger than a 500.. and there is way more parts for them..

seanbarney41 · « **Reply #7 on:** April 16, 2020, 05:44:04 PM »

sohc4's are all very similar mechanically...how small are your fingers? I have pretty fat fingers so I find the 750's easiest to work on. I would have to hire a small japanese woman mechanic to work on a 350 lol. Actually, I don't recommend trying to rebuild these engines. They were so damn well built from the factory and there are still plenty of engines that don't need a rebuild. Chances are your first attempt will be less than totally successful.
Lots of places to make very expensive mistakes when you could have already been riding a solid survivor...

Jaroldoe10 · « **Reply #8 on:** April 17, 2020, 05:03:32 AM »

Gents, this is all great advice. Thank you all. I considers the 500 because I agree with the size and look but I've seen around it's not great for a passenger. Let me know if that sounds about right. I think that is a great idea to buy one complete and have everything available. Can't find anything around me I'm Massachusetts. Tried CL... No luck. As to the small Asian lady.... I don't have any of those in my tool box so I might want to consider the 750 lol. I seen a few rollers on the internet around 3000. Was hoping to build the motor up then but the roller. It's true, I do want to ride it but I also don't want to be stranded because I didn't do the rebuild, or have oil drooling from the motor. I'll consider these things and if anyone else has any information to add please do. Thanks again guys, it's not often you get someone to share their knowledge with you. Appreciate it

bryanj · « **Reply #9 on:** April 17, 2020, 05:12:45 AM »

One big advantage of 500/550 is you dont need an oil tank

Stev-o · « **Reply #10 on:** April 17, 2020, 06:54:11 AM »

Quote from: Jaroldoe10 on April 17, 2020, 05:03:32 AM

Can't find anything around me I'm Massachusetts.

Your going to broaden your search, do you really expect to find exactly what you are looking for in MA since it is not really a popular model?

https://www.ebay.com/itm/2019-Honda-Chopper-Cb750/153805417317?hash=item23cf846b65:g:PKwAAOSwM81eKG4~

BTW - have you ever ridden a choppa?!

Jaroldoe10 · « **Reply #11 on:** April 17, 2020, 12:06:25 PM »

Never ever ride a chopper. Been looking around the internet as well. Not coming up with anything less than 1000 that doesn't have major issues. A guy about 30 miles from me just sold his entire bike for 100 bucks. Blah. Any idea if a "seized motor" is a good idea to buy and rebuild?

754 · « **Reply #12 on:** April 17, 2020, 12:49:11 PM »

It depends, it may unseize and run fine, it may need a cylinder pistols and head.
You don't know til you open it up. Stuff with the plugs out trends to be bad.
Arm yourself with a cylinder light, and always check the area in front of front sprocket.

jakec · « **Reply #13 on:** April 17, 2020, 02:41:45 PM »

the thing stopping me from building one is not know how to weld or do machine work and also not having the tools for it. If you can do that or were ready to commit to do it, I'd start with a fresh frame and just buy a 550 motor off ebay and rebuild it. You could get a rough bike and take the engine out and that may be cheaper than starting from scratch on just an engine. But then you're stuck with the other 75% of the bike you don't need. Or if you want to start with a built bike, at least find a bike on a frame from reputable builder. They do pop up pretty frequently (I post them here whenever I see them, just ask frank). Personally I've found all the built bikes out there to be ugly and the springer/girder front ends they're on are probably clapped out anyways. Just look at the two posted in this thread for evidence. There also seems to be only long bikes. (you still didn't say what kind of build you want).

Greyhound · « **Reply #14 on:** April 17, 2020, 11:11:18 PM »

Maybe I’m crazy, but I always thought of choppers as twins, not fours. Something just seems odd about a four cylinder chopper, just saying.

spotty · « **Reply #15 on:** April 18, 2020, 04:00:08 AM »

If you're looking for something a bit shorter and lower than a trad style chopper, check out 'digger' style stuff, just as cool but less common these days

Jaroldoe10 · « **Reply #16 on:** April 18, 2020, 07:48:24 AM »

Quote from: jakec on April 17, 2020, 02:41:45 PM

the thing stopping me from building one is not know how to weld or do machine work and also not having the tools for it. If you can do that or were ready to commit to do it, I'd start with a fresh frame and just buy a 550 motor off ebay and rebuild it. You could get a rough bike and take the engine out and that may be cheaper than starting from scratch on just an engine. But then you're stuck with the other 75% of the bike you don't need. Or if you want to start with a built bike, at least find a bike on a frame from reputable builder. They do pop up pretty frequently (I post them here whenever I see them, just ask frank). Personally I've found all the built bikes out there to be ugly and the springer/girder front ends they're on are probably clapped out anyways. Just look at the two posted in this thread for evidence. There also seems to be only long bikes. (you still didn't say what kind of build you want).

not quite sure what you mean for "build". if you mean what engine, I'm still trying to decide between a 500 and a 750. looking for easy maintenance and reliability. dont need a ton of power but do require the option to support another person. 500's seem more common and also look more fitting in the frame.

http://www.cycleonemanufacturing.com/hondacustommotorcycleframes.html

these frames look like a good option and are cheap enough. torn between buying a roller or piecing it together a part at a time. the advantage of doing it gradually is that I can save weekly and buy as I go which wont break my piggy bank to quickly. i probably could afford to buy a lot at once but I was hoping for the experience of learning as I go along. mind you this project is projected to go for a few years. I want gain the experience while building something awesome. any thoughts? im tipping toward the 500. someone save me from myself if its a bad idea. i got one in my cart for 200$ bucks runs. don't know what to do here

jakec · « **Reply #17 on:** April 18, 2020, 08:18:24 AM »

500 or 550? Just do it. But get a 550. Not a 500

when I ask what kind of build I mean do you want a long bike, stretched and rake frame, or do you want a digger, low flat long bikes (hate these haha). Or a bobber, basically just a hardtail frame with ape hangers?

Personally I think the frisco style chopper is the most popular & best looking, and there are still a million ways to do that. some people like to do moderate rake and a long front end to make the bike tall. if you look at the red bike I posted the bottom rail of the frame is about 2-3* off parallel from the ground. Personally I also like the telescoping front ends, cleaner and safer than a springer I think. And you could use honda wheels and forks, making it easier to source. There was a guy here recently that had a chopper and I think he used a small displacement wheel like a 125 or something so he had a really tiny drum brake up there.

jakec · « **Reply #18 on:** April 18, 2020, 09:32:26 AM »

This is kind of an OK start although he needs to reduce the price by about 75%.

https://www.facebook.com/marketplace/item/2869486909776357/

Jaroldoe10 · « **Reply #19 on:** April 19, 2020, 11:44:41 PM »

I really like the look of the red bike. So I'm guessing that's a..... What build? Probably would help if I could put a name to it. Thanks for that. Still unsure about the engine. Are 550 easier to work on them 750s? Harder or easier to find? I'm looking for reliability ease to work on and availability. Also, any ideas on frames? I want to make a purchase soon but do not want to be hasty . I don't mind taking time to go through the engine. I want it to be clean looking and rebuilt for reliability. I'd like to have the frame look like the picture you sent. Any suggestions as to which motor, what year and what I should be looking out for? IE. Certain years that the motor is less desirable for whatever reason. Like, for instance, I heard the later cb750 carbs are less desirable then the earlier ones. Any advice guys I need it. I want to be disassembling an engine sooner than later. Also any suggestions on the best manual to buy for working on them? I appreciate any input. You guys have been around these bikes and know a great deal. I've only messes with an xs 400 which I chopped and welded a hardtop onto and fabricated a wiring harness for. Until it got robbed 3 years ago... Quite a shame. Thanks again

jakec · « **Reply #20 on:** April 20, 2020, 09:46:45 AM »

I rode my 550 with a passenger and our combined weight was about 300 lbs. And it was fine. I weight 175 lbs. If you weigh over 200 then maybe the 550 will feel slow? I don't know. If you agree with me about the look of the engine then I would say go for it. I think the looks are important.

I've only had one 550 and it hasn't had any problems for me. I'm not an expert on them. But there are two issues that people mention here, 1. weeping oil at head (can be fixed at rebuild) and 2. early models cam shaft wallow (never seen it happen but can be fixed by swapping later top end on if you have an early engine)

The 550 clutch actuator is better designed than the 500.

regarding the frame and styling you should just read the article linked. the seat post isn't dropped like in the frame you linked. I'm pretty sure paughco makes a 550 frame? Where the top tube comes straight down from the neck to the rear axle. That's the look you want. If you got a vintage frame you could shop for a plunger frame, that's my favorite.

If you want to get started ASAP then just buy a motor since they're available, and shop for a frame. When you buy the motor just look and make sure all the fins are there, no broken or damaged side cases, no massively #$%*ed up screws, etc. If you want a nice polished motor when you're done but your cam cover has gouges in it from someone trying to remove a stuck tach drive screw, then you would need to repair the cover or get a new one.

Jaroldoe10 · « **Reply #21 on:** April 20, 2020, 02:36:02 PM »

Yes I agree, the look is really nice. I don't need a whole lot of speed, in fact if I can ever get my fiance on it in the first place would be a task in itself. Really just want it to cruise around. I feel like bikes already have a ton of power to begin with. I'm a little over 200 myself and my lady is maybe a little over 100 so I do t think it would be horrible. Again slow rides through the country is key for this build anyhow. So getting back to the frame, and actually everything else for that matter, what would you suggest for the forks, forward controls, electrical, braking etc etc. Should I just worry about getting the engine and working on it or is it a good idea to focus on future moves? Thanks. I'm probably going to rebuild the top end. Anything pressing I should look to replace instead of reusing like the valves cam pistons. Or should I just get a rebuild kit and clean it up. Looking into options right now as to how to clean it well without taking to a shop. Thx again Jakec and the rest of you guys

Bankerdanny · « **Reply #22 on:** April 20, 2020, 03:07:13 PM »

If the smaller engine is appealing, then as Jake said, go 550, not 500, and look for a 77 or 78 550 motor. The 550 has a improved gearbox and clutch setup compared to the 500 and the 77/78 550 models had an upgraded rocker cover that fixed a part that is subject to excess wear on the earlier bikes and isn't really repairable.

Jaroldoe10 · « **Reply #23 on:** April 20, 2020, 03:33:49 PM »

Awesome! Thx bankerdanny. That is super helpful. That's the kind of info I was looking for when it comes to choosing the engine. I will aim toward the 77-78 era 550. Any information on the carb system that is useful or any will do?

Jaroldoe10 · « **Reply #24 on:** April 22, 2020, 08:46:42 PM »

Hey guys, I just came across this bike. It turns over but doesn't run. It's a complete bike been sitting since 74... What do you think. Is it a good buy? Guy wants 1650 for it.

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Author Topic: Need help in deciding bike build (Read 3491 times)