1984 Honda CBX750F - A preview of an upcoming restoration
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- เผยแพร่เมื่อ 6 ก.ย. 2024
- Walk around of my 1984 CBX750F. This bike will get a full restoration this winter (2022/2023). In this video you'll see some of the issues and areas that need attention.
Im not a professional "restoration guy" its just a hobby, I'm learning as I go
We got these in NZ in this colour and in silver, we also got them with a full fairing called the CBX750 Bol D'Or. While I had a GPz750 uni trak, my friend had the CBX, so i got to ride it a lot, good bikes, I rate them higher than the VF750F cam eater of the same era.
We never got them here, this was a JDM import , quite rare on this side of the Atlantic
Hi Guys. I own one of these and know them inside out. It has almost certainly snapped the combined starter/generator chain. Very common issue. Take off the starter motor and you should be able to see the chain, nice and taut. If you cannot see the chain it's snapped. 99 out of 100 that's the cause, not the sprag clutch. The chains are long unavailable, but Tony Galea in England can make you one, and David Silver in England can supply a new tensioner, as it will be worn out. Beware, the later CB750 F2 and possibly the Nighthawk use an uprated chain, which is available, but It will not fit a CBX750F, as the crankshaft has a wider toothed drive to match the uprated chain, as does the sprag clutch. Change the cam chain whilst it's stripped as they don't last well either. Chains are available but you'll have to hunt down a new tensioner. CMS in The Netherlands usually have them. PS. You have to modify the seat with cut outs on a JDM model to fit the export type grab handle. The Japanese models were also restricted to 76bhp, not 90bhp like the export models, but below 7000rpm you can't tell. The Japanese 180kph limiter is allegedly built into the speedometer, so it's easiest to change the clocks for a Euro model which adds another 20mph to the top end if you also change the ECU and ignition to derestrict the engine. Hope this helps.
Thanks Mark, much appreciate the information and insights !! the reason I was guessing starter clutch is that when I first got it, it would start and the sprague clutch would engage about 50% of the time. After a while it would only engage 20 - 30% of the time, and now it doesnt engage at all. However Ill pull the starter etc and see whats going on with the chain etc . Thanks again for the tips !!! I really appreciate insights form a CBX750 expert !!
UPDATE: so you peaked my curiosity, and I had to pull the starter off right away. If I look WAAYYYY in there towards the left side of that case, I do see a chain. Secondly it seems the starter itself engages with the gear on the sprague directly, my issue is, that gear on the sprague will spin freely both clock-wise and counter clock-wise. Only occasionally will it lock when rotating clockwise as it should. The replacement starter clutch I have here locks immediately clockwise. my bigger concern now is, the gear on my sprague seems ever so slightly wider than the gear on the replacement (off a 91 night hawk). So when it all comes apart ill have to see if I can keep my current gears/shaft etc and just use the new sprague. Fun and games, if not ill contact David Silver Spares in the UK. my replacement (used) also came with a chain, but as you indicate, if its off a later model It will not fit.
again, thanks Mark, your insights are valuable, I may need to keep searching for the right parts here, we will see what will interchange and what wont.
@@true-moto-resto Hi. Glad to offer any help I can. Because of the common issue with snapping chains Honda uprated them, so the teeth on the later models are wider on the starter and the crankshaft to accept the wider chain. IF you can find a later crank too, it is a worthwhile upgrade, but these parts are scarce now. If it's just the clutch you must replace the chains too, they are weak, and the tensioners too. The replacement tensioners you see for sale are usually the later improved type which are a straight swap. Check the part number against the Honda parts catalog on CMS. As the crankshaft has to come out to replace the starter chain, and the camshafts to unhook the cam chain, it's such a big job you may as well replace everything you can, and hopefully you'll manage another 30k without issue. Word of caution, when stripping, watch out for the small oil dowels, one under the oil pump, one behind the gear selector case. If they fall out you will be scratching your head forever trying to suss where they came from. And do not put the cases back together until you have fitted the camshaft tensioner, which must be assembled in two parts around the chain. If you drop the fiddly securing pins you'll be stripping it down again. Best of luck! I'll keep watching the videos!
If you have a suggested method of removing the engine on a CBX750, I'd be keen to hear about it. the lack of a removable frame section makes it a bit of a pain. Ive seen people use a pole ands sling the engine on to and have 2 people lift it out, but re installing it without scratching the frame (after its painted) seems like an impossibility with that method.
@@true-moto-resto Hi. There is no easy method other than two strong men and some thick covers over the lower and front frame tubes. To give yourself vital extra clearance, before unbolting the unit, remove the lower oil pan as it will catch on the curve of the frame as the engine weight tilts forwards. The two oil feed pipes and strainer are just pressure fit into O rings, so will just pull out. Make a template for the removed bolts as they are different lengths. Likewise, with the coils off the cam cover is easily removed and gives some precious extra room. As the unit weighs over 80 kilos it's best to remove the heavy clutch unit before taking the unit out, and anything else you can unbolt as it all needs to come off anyway to split the cases. I discovered this the hard way. The second time I removed one of these units, having performed the above and removed the sump and cam cover first, was considerably easier, and both are simple to refit in situ. Best of luck.
@@marksaxton8918 Cheers Mark, yea ill remove a few things to lighten it ip and see what we can do
They arrived in Brazil as import for the first 800 units , and after they produced in large scale in factory in Brasil until they stop.
Beautiful machine and perfect sound of 4 cylinders 🇨🇦🇨🇦🇧🇷🇧🇷👏👏👏👊👊👊
Yes, I had heard they were popular in Brazil. Very rare here in Canada
I moved up from the Honda vf500 to one of these in the 80s think I paid £1.500 for it was red sprayed it all black fantastic bike at the time I weighed 10 stone 140 p and it felt light and easy to throw around am now 68 retired and I am thinking about getting one again but there's not many around in the UK
Thanks for commenting John, these never came to Canada at all, this one is a Japanese import . I think they may be more common in Australia ? Best of luck with your search, I’m sure there are a few still in the UK
Very nice! We in the USA only got the CB700SC, the CBX was way cooler. Looking forward to watching you get this one running!
Thanks Jim !
Remember when these came out, same time as Yamaha fz750 Kawasaki gpz750 (detuned version of the mighty Ninja no idea why) Suzuki gsxr750 and honda were already selling the vf750 (rumours lurked that the engine had issues) it was thought to be easier to service, lower cost option the cbx750. Must say it looks good.
Cheers Owen
Well if that a 5/10 i now feel the one i want to get to restore would be a 2/10. Most of the ones here dont even look as clean as that.
Well, maybe im a bit critical of my stuff, but, I figure if it doesnt run, and it needs a full paint job etc, it cant be better than a 5. You'll see in the series of 10 videos on its restoration just what it takes to bring it upto an 8
1. I can't believe how nuts that is that have to replace the starter clutch.
2. what do you use to have the headers/exhaust pipes for paint? VHT high temp looks alright, but it almost gives that texturey fuzzy look. Or do you send them out somewhere?
nice to see the Canadian internet hamsters could spin up enough bandwidth to upload an 8min vid in 1080p!
Hey Matt, I use Tremclad High Heat paint for the exhaust (not sure if you get that in the USA). Its a gloss finish and seems to be very durable and bakes on well after a few heart cycles. I do have one bike with a ceramic coated pipe (the CB1), it looks great too, its a Flat/Semigloss finish, but of course more expensive. The PO had that done to the bike. I used to use Duplicolour high heat "Semi Gloss" paint, but for some reason I have not seen that up here for some time. The other factor is cost, im usually on a strict budget for each bike, so ceramic coating isnt usually an option for me.
@@true-moto-resto Thanks for the response--It looks like I can get some of the Tremclad high heat shipped to Home Depot store near me for a decent price. I'd like to give that a shot just to try something a little different than the VHT I've been using to see if I like the difference.
For things like 1K or 2K color-matched (or factory specified) paints... Do you have a company put them into aerosols? I'm wondering if I can find the safety yellow RAL in a rattle can that I want to use or if I'm going to have to go the spray gun and compressor route.
@@matttriestodothings I have done both Matt, depends on if ive done just a touch up, or a full paint job. When I do a full paint job I go to the Auto Paint shop here and buy it RTS (ready to spray) in a 1 pint or 1 Quart can and use a Gun/Compressor. If its been a touch up, I have them put it in a rattle can, and then have it cleared by my painter (or me now that im doing my own paint work).
Rattle cans are very economical, usually $20-25, where as a pint of any paint is $75-100 depending on colour.