Topic: Double 750 F2 builds

[Evening Echo]

To start with, I ended up with two bikes when I went to buy one bike to do a project with. I was looking for something in poor condition as it would guilt me to much to not do a stock restoration on something that was worth restoring. When I got the second bike into the deal I was hoping to have enough decent parts to make one complete, fairly stock bike. Now that I have broken them down, this is not really a runner. To keep one stock is oging to cost a hell of a lot more than buying a mint bike.

I've started working on the 2 bikes and have decided to do two different types of bikes. One of them is going to be a racer style with a lot of fab work and the other is going to be a more comfy cruiser deus/wrenchmonkee type of thing with less customisation.

I am going to start with the racer bike. I have the engine already in bits (don't think you want pictures of that) and following an extensive search for oversize pistons for the F2 and ordering the wrong items (for a f rather than an f2 and they are very different!) I decided to go oversize and got the 836 kit from dynoman with new valves and guides as these were badly worn and rattling around in the guides. While the engine and head are at the machine shop I decided to focus on the look that I wanted.

Having looked around for a seat hump, I didn't find one that quite suited what I wanted. I decided to go the whole hog, make a plug, cast a mold to cast my own design hump. This way if people like it it would be possible to replicate the part.

As soon as I figure out how to post some pics I'll send on a sequence that may be helpful for others going this route. It is time consuming but very satisfying, and isn't that what messing with these old or any) bikes is all about!!

[Evening Echo]

Mocking up the hump, I wanted it to be a bit longer than the commercial variety while picking up the lines of the frame and tank

[Evening Echo]

This is the rough shape finalised.

[Evening Echo]

The next few photos are making the plug. I fibreglassed the foam shape, having included a seat base. Then I used copius amounts of body filler and sanding followed by a prime and paint with some 2 pack left over form another project.

[Evening Echo]

This was then used to make a mold. I painted the plug (it had been painted black and polished many times with a car wax) with gelcoat and then coated it with a few layers of chopped strand matting and ployester resin. I found that the plug was extremely difficult to remove despite the waxing and ended up destroying it in the process but I was happy with the mold.

[Evening Echo]

This time I spoke with the guy who supplied the products to find out about a mold release agent. He told me two wax and polish the mold as before but then give it 2-3 light coats of hair spay. This is essentially a water soluble plastic layer that will enable better release of the part. It worked although not without persuasion!

Here are the pics of the seat casting.

[Evening Echo]

The tape is showing where I think I might trim it although i'm not going to cut until I have a few more decisions made. I was going to use a bit of chopped matting and resin to locate a few captive nuts under the seat area and a spacer over the mudguard bracket to allow for a very strong and discrete fastening.

The measurements worked out to the millimetre. It hugs the frame rails and I can keep the rear of the frame intact as I had hoped. I was planning to use the mudguard bracket to hold an oil tank and the end of the frame rails to mount a removable bracket with number plate and indicators.

I would love to have a few comment/views from the more wizened 750 guys on here.

[SOHC4 Cafe Racer Fan]

Excellent seat. I like it both ways. The cuts make it unique.

[Evening Echo]

Thanks, although I have to admit that it is not quite unique in profile. I really like the wrenchmonkees Gorilla Punch bike but wanted to change the lines to match up with the rear frame tube to the seatback angle, and wanted to round it over a bit. Their tank hump is quite square and it suits the tank they have on that bike. I think the WM bikes look great, talented guys, and would like to incorporate some of the styling of their display type bikes with something more usable.

I want to keep the stock tank and am thinking about matching the lines of the seat with knee cutouts. I'm not sure whether to hammer them in or cut them out and re-weld yet. I'm not good at welding (plan on doing a course in June/July) but have a friend that could do it for me.

[Goody]

The seat is looking good, I think the squarer profile will go well with the stock tank.
I'm interested to see how you progress with these as I am doing a very similar thing, I to got 2 F2's in a deal when I was after 1 and was thinking along the same lines of doing 1 as a café racer and one more 'comfy cruiser'.

[madmtnmotors]

Looking good. I've got a couple F3's that will likely follow similar paths. One mild cruiser and another more radically modified. Keep posting picts! 

[Evening Echo]

The pics will be a bit slow for a bit. I am waiting on some items before I can get going again. I have rearsets coming, should be getting the bored barrels and rebuilt head back this week. I can put the empty cases together for blasting. I have had it done with a fine crushed glass before which gives a very good base for painting. I have found this a better option than say soda blasting. You just make sure to block up all openings and clean extremely thoroughly before rebuilding.

I do have to have an oil tank fabbed to go under the seat hump. I'll probably model it in foam and get it made up in aluminium. I also want to locate the electrics back there. There is plenty of space. I'll post some more pics as progress is made.

I would really like to change out the triple trees for some ceriani style or similar, without all the bracketry. I modelled one up in solidworks to get it priced and the lowest quote was €460 (about $600US) and that was just for an upper! The one that Dime City sell is the right idea but it is too square for the look I am after. Would anyone have any good ideas other of cheaper alternatives other than chopping down what I have?

Goody- it is a nice place to be able to look at building the two styles concurrently. I've also been looking at some of the street tracker type of bikes for my second build. I'm still tossing ideas around for this one but am pretty solid on the streamlined, minmalist bike that I want for the racer.

[Evening Echo]

I got the bored barrels and head with new valve guides back today and dropped it to my media blaster. He should be done in a few days. Then paint. Everything except the covers and barrels will be satin black. The barrels will be gloss and I found this charcoal grey metallic for the rocker cover, points cover, clutch cover and round area of the alternator cover. The plan is to use the same grey on the caliper, master cylinders etc also.

The engine "before" shot.

[Evening Echo]

My painter just called and tells me that one of the intake spigots on the head is cracked with a silicone repair. I would like to try and find someone with an F2 head that is being used for parts and try and scrounge one of these spigots. I did get an old head form a local bike shop but the spigots are smaller than on the F2! This engien is proving very costly! They do bolt in but might be difficult to remove after all this time.

I wonder can anyone help? I'm going to post this is the parts wanted section also.

[MRieck]

You need to really heat the area up and use a breaker bar and the right size socket. I use Mapp gas. There is a sealant in there from the factory and it has to softened. Use teflon pasted when putting it into the head. Good luck.....it is a bit of a crap shoot.

[Evening Echo]

Thanks mike. From what I read here you are the guy who knows how to work these heads so all advice is very much appreciated. Perchance would you have one of these in your stock?

[Evening Echo]

I ended up getting a new intake spigot machined. I did find a donor head from a local shop but after removing one of the spigots I realised they are not the same size so just got one made up instead. He did a beautiful job. Now the painter can finish up, should be done in a few days.

I also go the swing arm lengthened by 2 inches. I wanted to stretch the bike marginally without drastic alterations. I will need to find shocks about an inch longer than standard to achieve the stance that I would like. The piece of wood between the back wheel and the frame gives me the approximate stance.

The update that I like most is something I haven't seen before but I'm sure it has been done. To get a bracket free upper triple I bought a lower on fleabay. I had the stem pressed out, filled the holes and machined off the lugs. It needed a bush pressed and then bored to get a clearance fit on the stem when installed as an upper. I kept the horns at the front intact to use these to mount a bracket to hold the clocks. Using a lower also effectively drops the front end by about an inch as there is no height offset on the holes. This helps with the stance without cutting the fork stanchions.

I also received some nice small clocks and beautiful tarrozzi rearsets. I will have to make up brackets to hold the rearsets as I can't find any off the shelf that fit the F2.

I am looking forward to seeing how big an impact these changes will have on the bikes handling.

I got the tanks back from the media blaster and had them primed. They are badly dented. One of them is terribly rusted internally but the other one is quite clean. I don't know yet what I will do with them. Use them, cut them, lose them.......

Photos below. I know how much we all like the pics. Sorry for the poor quality but I am working in a pretty small space with two bikes up at present.

[Evening Echo]

Small Update.

Mocked up the rearsets with some timber and got some 6mm sheet cut by laser. If anyone would like the cad file let me know. I may redo them as I am thinking the right hand side could also hold a nice little brembo master and possibly an exhaust mount. If I do redo them, I would cut out the centres as per the tarrozzi rearsets to lighten the look. The 6mm steel is strong enough to cope.

I mounted the old exhaust to try and figure out what I what to do here. The bike came with a motad that is quite beaten up. I may cut this down and Paint for now while I figure this out, want to keep it low but have not decided whether to go custom or buy one of the nice looking systems out there.

I also got the engine and a few other bits back from the painter and started rebuilding. What a B@tch to try and get the barrels back down over the big bore piston rings.... Also realised that not everything was present before I broke the engine down so will have to wait on some small bits from DSS... I hate the waiting....

I broke a stud while removing the old to replace with HD Ape rods. Had some helicoils from a previous fix so that got solved quickly at least.

I now need to decide what to do about the oil tank and try and find a physically smaller battery that will do the job. I don;t want to lost the electric start so will have to figure out what is the smallest physical size to do most of the original functions. Loads of threads on this so will need to figure it out unless anyone has a quick solution..?

[Evening Echo]

I decided to take a step back with the cafe project. I realised that for some of what I wanted to do I didn;t have the skill set and didn't want to do a half job. That and the birth of our second child put the slowburners on that project for now.

To keep me going I decided to use the rebuilt engine in a rebuild for the time being and if nothing else it would teach me a bit about the nature of these bikes.

Also, I undertook a two week evening tig welding course which I really enjoyed; that well let me get on with the cafe project in due course.

On the rebuild, I decided to use the best bits from the two bikes, debadge and repaint the plastics. Repaired the tank which was in a pretty bad state. I pulled all the bad dents and welded in patches to the old emblem fasteners. I also had the chrome engine pieces painted as they were so badly pitted. other than that everthing got a good clean and rebuild.

I finally got it out for a little run this evening, despite missing a fuel tap (I found out too late that the tank have different size bungs and I did up the wrong tank for my one petcock!) which is on it's way from Honda. The engine has the 836 wiseco pistons, valves, guides, springs, ti retainers, chains. I used a David Silver electronic ignition, the original coils, new plugs and caps. It fired the first time I pushed the button....I couldn't believe it, I don't think that ever hapened to me before!! This evening I couldn't believe how well it ran with just a bench sync on the carbs and zero tuning. I expected rough running, if at all, after installing the big bore and not doing anything with the jetting.

This is now going to be a rolling project while I do a full custom with the other bike. Ignore my temporary fuel tank (covered in a rare Honda vintage sock!) I can now decide at my leisure what to do and do it as extra funds and time are there. I think I will enjoy riding it in the meantime.

Just to dress it up a little bit I think the only thing I will do to the painted items is put on some of the old winged decals to either side of the tank. I like it to be pretty understated rather than too bling.

The first thing I will do is get the suspension sharper and I would really appreciate some ideas for significant improvement, on a budget.

Pictures below. Sorry for the poor quality, thy are taken with a phone. I saw the decal on a friends old dirt bike and really liked it.

[Evening Echo]

Well, it's been quite a while since I posted. I had almost a year of fun on the Black Bike until it was stolen right in front of my house while it looked like this........ I had just tidied up the rear end a bit and was about to do away with the big front blinkers.....and it was running just great with the hotter cam and the 836cc's

[Evening Echo]

And was recovered by the police a week later looking like this. Utter B@sterds!!!! I did get the carcass back from the insurers as they were not to know that there was close to €800 of new parts inside the engine case.....

[martin99]

Absolute fkucers. Gutted for you mate. Hope you catch up with the low-life baastards and wrap that burnt -up frame round their fkucen necks

[Evening Echo]

It's the time and effort that you put in that is the real pisser; and the satisfaction of resurrecting a basket case. The insurance money covered the hardware, I didn't have too much tied up in it; but you can't get back your time!!!! It had become my go-to bike, comfy and torquey, fine in town, great on the more open roads.

[BPellerine]

man that just sucks!bill

[Evening Echo]

Anyway,  such is life. There are scumbags all over, just as there are also great people! Very philosophical tonight!

I'll start a fresh thread with the development of the other more customised f2 (now incorporating some salvaged bits). It has been moving forward, very slowly, but forward all the same.