Vintage Dirt Racing on a 350 Honda Twin

[Pantah]

Originally Posted by LC Garage

Wow, it's been almost two months since I've posted on my own thread! It's been a real whirlwind lately with the MK1 prep (see OregonCoast's thread) and prior to that the Desert 100. As most of you know, we just returned from Baja, after successfully pitting Paul's '72 SL350 against other bikes new and old. The final result was first in class, eighth overall in bikes and the adventure of a lifetime!

The team in Cabo;



Hard to believe my involvement and eventual participation in this all began not long ago with a good friend (my buddy Don) dropping off my old SL350 and saying it was mine, as long as I promised to ride it in vintage races. One thing led to another, and now I'm at home, still decompressing from Mexico and trying to comprehend and appreciate it all. Wow!

As I write this, what I am struck by is how great it has been the last year or so to meet so many new friends and enjoy these great adventures, that all somehow relate back to our mutual love and appreciation for motorcycles. I am truly blessed and thankful, and glad for all of you who have participated, whether at the track, in the shop or just following along here at ADV.

I have not made plans too far in the future, but I do know we are going to rebuild my old twin for the Chehalis Vintage Nationals (as soon as I figure out where my motor is, I think it's in Spokane with Lady Bug! ) and the wife and I are definitely planning on taking the RV up to Odessa next Spring for D100, but not sure yet what I'm going to ride??

Today I started to clean out the shop, it was looking like a cyclone had blown thru, layers of parts and tools everywhere! After that I repaired the fuel pump on the John Deere so I can begin catching up on mowing, and finished the day servicing and washing the Shadow 750, so the wife and I can take a ride tomorrow. In June we are taking the Shadow over to the Hells Canyon Rally just for a good cruise.

Thanks for following along!

I enjoyed your adventure thoroughly. My son was on #5 so I tried to follow as many as I could, but especially the two Honda twins. Congrats to everybody who built and brought that baby home in style.

-P

[LC Garage]

Originally Posted by Pantah

I enjoyed your adventure thoroughly. My son was on #5 so I tried to follow as many as I could, but especially the two Honda twins. Congrats to everybody who built and brought that baby home in style.

-P

Your son is Gus? Didn't he finish the race with a broken wrist?? Pretty gutsy and a class win to boot!

[Loud Al]

Originally Posted by LC Garage

I have not made plans too far in the future, but I do know we are going to rebuild my old twin for the Chehalis Vintage Nationals (as soon as I figure out where my motor is, I think it's in Spokane with Lady Bug! )

It is sitting in my garage

[LC Garage]

Originally Posted by Loud Al

It is sitting in my garage

OK, cool! I'm sure you will want me to get it out of there ASAP, will talk to you this week and work it out. Thanks!

[LC Garage]

Went for a country cruise today with my wife and best friend Jan, all back roads, 5 hours of riding, 180 miles and lunch in Astoria. A really nice day for a slow putt.

Bike and wife all shined up for a cruise;



At Astoria's Sunday Market;

[oregoncoast]

It looks like it was a great day for you two!! Laura and I also enjoyed ourselves today, walking the beach and cleaning the garage so I can fit the bike back in there!

[LC Garage]

It seems like a long long time since I've actually worked on the old twin and have still been catching up on months of honey-do's and projects. Before launching into the SL350 update, here's a brief recap of our latest adventures;

A few weeks ago, with Luke and Jan's help the Austin Healey was finally driven for the first time since bringing it home almost two years ago. Carbs rebuilt, tuned up, new brake hoses and several minor repairs here & there, and she ran better than expected and sounded exactly like a sports car ought to! Next up for that project is a new water pump, cooling hoses and fan belt. After that we are taking it to a detailer for a clean and polish.

Here is a pic right before we took it off the jackstands and drove it;



The next weekend we put 850 miles on our Shadow, riding to Hells Canyon and back for the "other" Hells Canyon Rally (not Lady Bug's event), despite a very cold and wet ride over, we were rewarded with decent weather there and great weather on the return trip home. Here is the bike at Hells Canyon Inn, just a few miles from the Idaho border;



Upon returning home and after completing a few more items on my domestic list, I announced that if we were going to make it to Chehalis VMX Nationals this year, we would need to devote some time to the old twin, so this weekend we actually started in on SL350 T98 2.0. Part of the plan for this year was to lighten the bike as much as possible, the other was to add some much needed power. I have been doing a lot of reading about the old 350's (as well as getting advice from Mr Fast) and was somewhat hopeful that the big bore kit in the old parts bike I brought home last year (reputed to be my original Powroll "400" kit installed in that motor back in 1985) was (A) Still in good condition and useable and (B) 67.5 mm, as from what I've learned this is the largest bore possible without sleeving and is also AHRMA legal.

Here is the old parts bike, ready for tear down;



Motor out and ready for disassembly;



First look inside, hmmmm, appears nice and clean;



Next layer, still clean;



Still looking good, no apparent damage yet;



Would I get lucky on the bore size? Yep!



Hardly a mark on the pistons and cylinders, the only problem found was one of the wrist pin clips was missing the curled ends, but could not determine when that happened and there are no markings to indicate it had broken off when running;



"Powroll"



Camshaft (two views), numbers on cam are 0 &1 and 8 & 11;





So now the search starts for piston rings & gaskets (hoping Bore-Tech can help on these), a variety of smaller pieces and identifying the cam and head. The ports in the head appear to be stock (aside from minor flash clean-up ) and the intake bores are approx 29.8 mm. If anyone has info on cam and head identification, I'd appreciate any guidance possible.

Once parts are on the way, next step is to clean, prep and paint the frame (powder coating is out for version 2.0, not enough time or money right now) and going through the many boxes of parts looking for the best pieces and grinding, drilling and otherwise lightening anything possible before reassembly. It should be a busy July!

[Ladybug0048]

Nice to see you are working on your SL350.....

Now about your choice of Hells Canyon events to attend With that bike you chose the right one, it wouldn't have fit in with all the adv bikes.



Good luck in Chehalis.

[Mr Fast]

Didn't realize you were into old British cars. I've got a real nice TR-3A & Jrs. got a TR-250. Looking at that motor of the SL it looks really good. With the Powroll conversion I don't imagine it's got a stock cam. Any idea what it is?

[LC Garage]

[QUOTE=Ladybug0048;18992429]Nice to see you are working on your SL350.....

Now about your choice of Hells Canyon events to attend With that bike you chose the right one, it wouldn't have fit in with all the adv bikes.


Maybe we should put adventure tires on the shadow??

[LC Garage]

[QUOTE With the Powroll conversion I don't imagine it's got a stock cam. Any idea what it is?[/QUOTE]

I was hoping you (or one of the other CB350 aficiandos) would know!

[Mr Fast]

Originally Posted by LC Garage

[QUOTE With the Powroll conversion I don't imagine it's got a stock cam. Any idea what it is?

I was hoping you (or one of the other CB350 aficiandos) would know! [/QUOTE]

Go to megacycles website. They list the different cams with lift, duration, etc.

[LC Garage]

While waiting to find the various pieces needed to build the motor, I decided to get a jump on the chassis and spent about 3 hours today, cutting, drilling and grinding. The net weight savings as a result of all that work? Maybe a pound, maybe less...

Before;


After;


Every mount, flange or bracket was ground, reduced or minimized and 22 more holes were drilled. The triple clamp also got a good massage. One more evening of grinding and sanding and then a few coats of paint and it will be ready for reassembly. I will be pulling the swingarm and steering bearings to service (or replace) as needed. Every piece that goes back on the bike will be reduced as much as possible. Nothing can stop me but fear or common sense!

[Loud Al]

You better weigh that paint before you put it on the frame, you don't want to undo all your hard work

[LC Garage]

Originally Posted by Loud Al

You better weigh that paint before you put it on the frame, you don't want to undo all your hard work