1990 750 Sport Rebuild

[dtm79]

Nice to see the work getting on .. calipers look good. Have to say bit envious of the weather you seem to have .. Uk wise its bloody cold and threatening more snow ...going outside to start repairs on workshop roof (in the cold). Decided after reading the various posts to leave the sport I have original ... it seems to have spent most of its life out of the weather and is as far as I can judge 100% down to the toolkit ... Only thing lets it down is the finish on the engine which is losing its paint plus the bar grips. Keep Going & All the Best. dale

[jcslocum]

Be careful when replacing structural bolts with stailless as they are not as strong and can/will break under load. I would NOT replace caliper bolts with anything but the exact replacement...

For soda blasting, I will be making this rig.:

http://www.aircooledtech.com/tools-on-t ... a_blaster/

[jpitz31]

Nice to see the work getting on .. calipers look good. Have to say bit envious of the weather you seem to have .. Uk wise its bloody cold and threatening more snow ...going outside to start repairs on workshop roof (in the cold). Decided after reading the various posts to leave the sport I have original ... it seems to have spent most of its life out of the weather and is as far as I can judge 100% down to the toolkit ... Only thing lets it down is the finish on the engine which is losing its paint plus the bar grips. Keep Going & All the Best. dale

Thanks Dale, Yes I hear the weather this winter in the UK is down right awful. Snow and very cold. My Sport was the same, The engine and metal bits were just down right cruddy. I could not take it anymore. I figured since I was having all of the problems with the bike I might as well tear it down and do it right.

Cheers

Joe

[jpitz31]

Be careful when replacing structural bolts with stailless as they are not as strong and can/will break under load. I would NOT replace caliper bolts with anything but the exact replacement...

For soda blasting, I will be making this rig.:

http://www.aircooledtech.com/tools-on-t ... a_blaster/

Yes Jon, If I replace the caliper mounting bolts I will keep them steel. Very cool soda blaster, Keep the nozzle size as small as possible. You want the soda to really blast out of the nozzle or it has little effect on the blasting.

After the good results my son and I have been having we more than likely will build a better rig.

Thanks

Joe

[dtm79]

Hi Joe ... Where you getting your bar grips from .... Decided just to leave my 750 as it is including wheels and tyres... first time I rode it I didn't check the tyre pressures ... hell of a ride with a flat front tho !

dale

[jcslocum]

You want the soda to really blast out of the nozzle or it has little effect on the blasting.

After the good results my son and I have been having we more than likely will build a better rig.

Maybe some of the industrial sized soda? The Arm and Hammer baking soda may be too fine?

[jpitz31]

Hi Joe ... Where you getting your bar grips from .... Decided just to leave my 750 as it is including wheels and tyres... first time I rode it I didn't check the tyre pressures ... hell of a ride with a flat front tho !

dale

Dale, I have not gotten that far yet. I am still trying to find a replacement plastic throttle. I am eying the new throttles on Bevel Heaven, but I will try to find the replacement plastic throttle first.

Cheers

Joe

[jpitz31]

You want the soda to really blast out of the nozzle or it has little effect on the blasting.

After the good results my son and I have been having we more than likely will build a better rig.

Maybe some of the industrial sized soda? The Arm and Hammer baking soda may be too fine?

Jon,

There may be a difference in size, But Harbor Freight only sells a big bag for $39.00, Way too much for what I need.
I have not checked on the web because I hate to pay shipping on baking soda

Arm and Hammer worked just fine for me. I am doing some more experiments with a different setup. I will keep you posted.

Thanks

Joe

[jpitz31]

Well I spent the last week-end powder coating and painting various parts. I have discovered a few tricks to powder coating. Pre-heat the parts that you want to powder coat. Then as you spray the powder on to the part it starts to melt and adhere to the part much quicker.

Since I am using the Harbor Freight inexpensive gun there are a few tricks with the application as well. Clean the gun after several applications. It appears that powder starts to build up in the tube as you are spraying parts. Then when you tilt the gun down to change the angle, trapped powder falls out of the tube on to your part and leaves an uneven surface. By using compressed air to blow out the gun every few applications the powder does build up in the gun.

The hardest parts to spray are the parts that have many sides or angles to them. As you spray these parts the powder then builds up on the parts unevenly and can leave what looks like orange peel on your surface.

When spraying powder it is really hard to tell if your part is evenly covered. After the part is cured and removed from the oven it now becomes really apparent of the areas that you have missed.

I have found that if you lightly sand the parts with 320 grit sand paper and wipe down the part with acetone you can now re-coat the part and get very good results. But you must re-coat the entire part. If you only do one section the rest of the part will have a nasty look of over spray.

The same goes for orange peel. Powder coating is very sensitive to powder thickness. If you apply too much in one area and not enough in another will cause the part to orange peel like and the thickness changes will be very noticeable. The best solution is to sand, wipe down and re-spray the entire part.

I also have noticed that the powder from Harbor Freight is not as good as Powder by the Pound. The Harbor Freight powder orange peels much easier than the other powder.

Here are some images of the finished parts.

Here is a shot of the swing arm chain adjustment caps, axle plates and fairing brackets. The gold powder coat is from Powder by the pound and goes on really nicely.



Here is a shot of the instrument cluster bracket, clutch master cylinder and a few brackets.

The master cylinder was a pain to shoot because of the size and many angles.



Here are the exhaust header sections.

These were not powder coated. They were painted with POR15 High Temp paint and cured in the oven at 400 degrees F.



Same goes for the exhaust pipe ends. POR15



Next week, more work on polishing the swing arm and rear sets.

Thanks

Joe

[jcslocum]

That stuff looks great!!!

You have given me the courage to think about getting a powder coating rig and so this too. No more rattle can on the parts. Maybe.... I have to find an over first.

[jpitz31]

Thanks Jon,

I got my oven for free on Craigslist. My biggest expense was wiring in the 220 out in the garage. But with the plug now I can dream about the plasma cutter and tig welder.

Joe

[persempre907]

Very nice results and it seems not so hard to do.
Thanks for sharing.
Ciao

[jpitz31]

Thanks Francesco

Joe

[jpitz31]

Well it is raining again this week-end, so no painting or powder coating.

My compressor died last week-end so I am also down for this reason. I ordered new parts and hopefully I can be back in business next week-end.

We are making good progress with buffing, It really helps to have a son who recently graduated from UCSD with a degree in Computer Science, who can't get a job. I have put him to work doing all of the dirty cleaning and some of the buffing.

I am going to have the frame powder coated by a local shop, It would be too much to build a larger oven, cheaper to pay the $200.00 for frame.

I am almost ready to start in on the engine. I am going to leave the body fairings for the last project.

Here is a shot of the buffed chrome.

It is not perfect and I do not plan on removing every little nick to make a complete mirror finish. I could easily drop a few hundred more hours in buffing.



Thanks

Joe

[jpitz31]

Well, with the compressor down this week-end we decided to start in on the engine.

We pulled the heads and cylinders. Pulled the clutch pack, removed the clutch housing. Pulled the alternator cover and removed the starter.

We then disassembled the heads, labeling parts and placing them in plastic bags for the machine shop.

I used a trick in removing the opening and closing rocker arms. When I use to do a valve adjustment on my 748, you had to pull the cams. I used a small body dent slide hammer to remove the cams.

I discovered that I could to the same when removing the opening and closer rocker arm shafts.

Here are some shots from this week-ends work:



Right hand side of the engine.




Left hand side of the engine



Cylinders and heads



Using the slide hammer to remove the rocker arm shafts

Joe