Owned a 900SS back in 1979/80... Lovely Bike..sounded great when opened up, sounded great when engine over running, induction roar from damn great Dellortos ....whats not to like...Motorcycle Heaven.....People test ride them now and say 'you have to get used to a new way of riding'... Hell! we already knew, we were of the time.... Japanese bikes of the day couldn't hold a candle to a Duke 900SS or a Guzzi 850 Le Mans for that matter..

WOW.. great video..! I did this in 1986 to my 900 SS Desmo with tools loaned from Ducati of Sunnyvale. That was a great learning experience.!!

Excellent informative video. And no greasy fingers on my part! Thanks.

Thank you for making this video. I bought a 750 GT engine in a box and would love to build it myself, information is the key I guess. Once again, thank you

Thank you for making THE ONLY video on this! Would love to know the dimensions of your fixture.

Very god video! But I would soak the gasket in oil. I use a plastiq strap to lock the spring instead of the factory tool.

A very well done video, thank you! But I'm confused, how can you determine the correct play of the closer shims if the bearing cover of the camshaft is not in place and the camshaft is only guided on one side? Was it just left open for the video?

@tdkeyes1

3 жыл бұрын

Good eye and you are correct. Both cam support blocks need to be in place to properly shim the valves.

I was always confused about the early L twin's. Is it correct that the 750 GT, 860 GT, and the later 900 SD and SSD were valve spring heads and that only the 750 SS and 900 SS versions were Desmos?

@tdkeyes1

3 жыл бұрын

The 750 GT and Sports and 860 GT and GTS are spring heads. All SS and Darmah and SSD models are desmo. Of course, all have bevel drive cams.

A timely video; time to get my 81 MHR back on the road after 27 years of looking pretty in the garage. I'm very interested in where to buy valve shim kits. Is there a kit that contains a range of top hats, half rings and the other parts?

On the other hand, bevel twins do that sometimes, but not for as long a period as yours. My 1976 GTS started smoking heavily from one pipe after I had the bike in for service. I didn't know that this was somewhat common, so I stopped and adjusted the carbs and after that there was no smoking for 40,000 km.

If radial engines have such bevel driven overhead cams, single camshaft on one supercharged intake valve and knocking the rocker arms to open 2 exhaust valves, and water cooled to reduce gear backlash, how much HP boost could we gain against the WWII radials?

@tdkeyes1

4 жыл бұрын

You should have a look at the Rolls Royce Merlin engine. In-line V-12, water cooled, supercharged, bevel gear driven overhead cams.

@zooplanton

4 жыл бұрын

@@tdkeyes1 So compared to its air-cooled pushrod radial contemporaries, it achieved 4:3 power advantage. Merlin actually has a little bit better power to weight ratio. So if the compression ratio could be doubled to that of modern car engines, if the rpms could be doubled, the performance could have a greater boost.

@tdkeyes1

4 жыл бұрын

@@zooplanton If only. Water cooling is far superior to air cooling especially with multi cylinder engines. Imagine the cooling and sealing issues with a 27 cylinder radial. Compression on these engines is really dependent on boost levels and available octane. With modern injection technology, computerized engine controls and modern manufacturing tech one could produce significantly more power.

I really like the setup jig , is the other bearing for setting up a bevel single ? I am going to have to replicate that for my workshop , Cheers mate.

@williamjohonson5459

4 жыл бұрын

I should have watched the rest of the film , it's now obvious 😉

@tdkeyes1

4 жыл бұрын

@@williamjohonson5459 When I made it up I had both twins and widecase singles so that was what I had on hand to measure.

@williamjohonson5459

4 жыл бұрын

@@tdkeyes1 it's such a great tool , I build a lot of N/C & W/C singles so if I work out all the pcd's I should be able to use it for all models , well next on the bench is a 24H which has the same spacing as a 175 , I think ! Cheers

Servicing a 74 gt750 motor...had to replace camshaft bevel gears with a new matched set. How do you determine the amount of shims to use behind the cam bevel gear?

@tdkeyes1

5 жыл бұрын

A new matched set would be shimmed the same as the originals. The new gears should have the factory grind marks on them. With the cam in the head and the gear placed on it, bring the cam gear and the bevel shaft together to where the proving grind should lap, then measure the gap between the gear and the cam. This will give you a good starting point for shimming. Do the same with the bevel shaft, measuring it's gap, between it and the bearing it rides in. This should get you close and then it becomes a question of fine tuning the shimming, watching the off-set between the two gears at the proving grind. Hope this is a clear answer.

@ptzpntbll

5 жыл бұрын

@@tdkeyes1 i have timing marks but no proving grind. This set came new from "back to classics" out of the netherlands. Great website for parts but maybe not factory?

@tdkeyes1

5 жыл бұрын

@@ptzpntbll That certainly makes it a bit more difficult, but not impossible. You will need to get some of the yellow paste used for setting up differentials. Follow the setup procedure as you normally would. Once you get the gearset shimmed in place, apply the yellow paste and check the pattern. You will probably be close but you'll need to fine tune it, to get it right may take awhile. There are a number of videos on setting up differentials on youtube. The procedure would be similar.

Great video, thanks! Do you have plans available to make a jig like that please?

@tdkeyes1

5 жыл бұрын

I had but there is not enough interest to make it worth doing.

@brnsrgn

4 жыл бұрын

@@tdkeyes1 I'm interested

@cyberspooky

4 жыл бұрын

I’m interested

@zumwild

4 жыл бұрын

@@tdkeyes1 Me too, I'm interested.

hi - great video - do you have the dimensions for the jig you made - starting a rebuild and it would be a big help to make one. cheers

@tdkeyes1

5 жыл бұрын

Unfortunately I don't. I paid a machine shop to dimension the bare head's hole centers for both twins and a wide case single, with the intent of perhaps selling a few jigs. Be aware that the twins heads have differing cam drive off-sets. All I ever got was the one drilled & tapped alloy plate before they closed shop and disappeared.

@GTRtonyd

5 жыл бұрын

Thanks. Great idea. I will try to copy it

This is good timing, I have a chance to own a MHR. its been well rebuilt rebore new pistons new updated oil pump, but it has started to smoke after about 100 miles. Any thoughts? I heard a rumour of a batch of bad pistons?

@tdkeyes1

7 жыл бұрын

The smoking could be caused by a number of things. Who did the rebuild and how extensive was it? Is it smoking from both cylinders or just one? Odd that it started smoking after 100 miles. That would lead me to think something failed. It is most likely an issue with either valve guides or piston rings. Who had a batch of bad pistons and what exactly does that mean?

@burtjohnson7298

7 жыл бұрын

tdkeyes1 high thanks for the reply, could you mail me at magnahelic@gmail.com I dont want to name names just on a rumour. Thanks again

Why no oil during this demo?

@tdkeyes1

5 жыл бұрын

Hello Alvaro, I use a light spray oil, JB-80, when putting these together. I may wipe them clean when checking clearances but I always oil them up when I done handling them. I do not recommend using WD-40 as it is really not a lubricant.

Hello can you build me one of your jigs???? Robert

@tdkeyes1

Жыл бұрын

Unfortunately the machine shop that I paid to build the machining file so I could reproduce this went out of business without giving me the file.

@boredmalcontent

2 ай бұрын

I could build you one

NO assembly lube who needs it?

@tdkeyes1

4 жыл бұрын

I use a light oil when fitting everything together. When it's all done I'll flood all the moving parts with motor oil and top up the crankcase and prime it by spinning it without the plugs in it.