Project SL 175 Motocrosser

[Old Rat]

I have been collecting Bridgestones and Hodakas for some time. I have (2) Dirt Squirts, (2) Wombats, Combat Wombat, SL 250 and SL 175. I want to transform the 175 into a fast MX bike and start racing VMX with it. I'm looking for advice on what to do first to the engine and suspension to make it more competitive. Looks like there are plenty of experienced, Hodaka experts on this site with some awesome bikes. Any advise, contacts, after market suppliers, etc., you have to offer would be appreciated.

[olddogs]

I know, that sexy cylinder head on the 175 shouts "I am a serious machine" but it kinda ends with the shouting. I tried this exact same thing. I used aluminum rims from the 250 ED, the cdi off the SL250, Works rear shocks, cut off every bracket and part not essential for holding it together. It landed from jumps like a refridgerator filled with bowling balls, Thud. The engine is basically an SL250 with a smaller bore. It is 75 pounds heavier than the Combat Wombat but makes up for that by not having as much power as the Combat can with just a few modifications. Theres a guy named Rich who can modify the 175 for a reed valve and port for real power, but the weight is hard to overcome. I had 10 times the fun when I switched to racing the non reed Combat Wombat or reed valve Super Combat. Fork and shock upgrades to either of these 125s makes a lightweight fun racer. Parts are plentiful and cheap. As a duel purpose rider, the 175 is fun machine, and one great looking bike.

[olddogs]

Check Rich's Taylored Porting for hop up ideas for the SL175/250 engines.

[Old Rat]

The combat was going to be my next project after the 175 so sounds like I should rethink that. Would a SL 250 MX project bike be a better choice than the 175 or not really?

[olddogs]

Nope. The 250 engine platform and frame whether SL175/250 or ED250 is just to heavy for a decent power to weight ratio without major and costly mods. The 250 Sl is a 280 pound bike, the 175 at 268lbs. Removing 20 pounds of brackets, lights and blinkers doesnt even make a dent. The CW is 190lbs. You can use the 250 forks by changing the stem and add inch longer rear shocks to balance the stance and make the 125 a capable ride. Fork springs and shock springs can be sourced for your weight.

[matt glascock]

Six of one, half-dozen of the other. Build up your Combat Wombat and you'll have a rip-roaringly fun race bike. Alternatively, if you can get your hands on a 250ED, you have the start of a great race bike.

[thrownchain]

It should come down to the class you want to race in.

[Dale]

You might want to discuss building 175 race bikes with Hodaka specialist Ron Liddle. He has been involved with some very nice (and fast) 175SL MX builds.

[Old Rat]

Awesome! How do I get up with him?

[Dale]

Awesome! How do I get up with him?

Well, his contact info used to be posted on the Strictly Hodaka web site but I find that it is no longer available. If you are a club member, you can log into the club web page and look him up in the directory. If not, I can PM his contact info to you. I'm just not where I could do that today...

[Tether]

PM sent with Ron’s contact information
Ron has rebuilt several engines for me. Top notch work and he is just a great guy.

[Dale]

PM sent with Ron’s contact information
Ron has rebuilt several engines for me. Top notch work and he is just a great guy.

Thank you Bob!

[swcaudill]

Didn't Paul Stannard have a 175 framed race bike with a ED250 engine? I have a SL175 frame that has an ED250 engine that is a great play bike. The frame was given to me by Mike Perrett The engine has a Suzuki head (modified by Mike P.)
Sterling

[MTrat]

One of the best looking Hodakas I've ever seen is the 175 racer built up by Ron Liddle. I'm not sure who helped with the cosmetics.

[Dale]

One of the best looking Hodakas I've ever seen is the 175 racer built up by Ron Liddle. I'm not sure who helped with the cosmetics.

Mike Allen for sure. Not sure of others involvement. It is an incredible build. I wish that I had a picture to post.

[Dale]

I found this picture posted by Kelly (socalhodaka) after the 2015 Hodaka Days Scrambles. Here is Jay Lael piloting a very fast 175 SL build. I believe this to be a Ron Liddle/Mike Allen build. Someone please correct me if I am wrong on this.

Hodaka Days Scrambles 3.jpg (85.05 KiB) Viewed 6080 times

[Old Rat]

Very cool! Hope mine turns out that nice. Thanks!

[olddogs]

I would suggest you research the racing organizations and tracks in your area, including the classes available for you to compete in. Not all areas have AHRMA style tracks. When we raced VMX from 2010 thru 2016, there were 2 classes, a 125 class that ran in the same heats as the open class vintage bikes. The bikes were limited to 1976 and older vintage motorcycles and ran on the regular MX track between the modern heat races. 4 foot deep whoops, table tops and doubles jumps were around every corner. On the starting line you would be facing 212 pound mono shock YZ250s, 214 pound 250RMs, 205 pound KX250s and and endless stream of 250 and 400 Huskies. I found it much more fun to compete in the 125 class as the CW and SC Hodakas were much easier to make competitive against the other 125s of that era. If your heart is set on 175 or 250 go for it, its the smiles at the end of a race that will matter the most.

[Old Rat]

I'm going to try and build both the combat and 175 for me and my 25 year old. I've been checking out tracks for vmx. Monster Mountain in Tallahassee, Alabama is one of my home tracks. It has modern national MX and a Vintage mx tracks on their property. At one time they even had a supercross track. James Stuart used to practise and race there years ago.I race there on a regular basis doing Harescrambles which combines their 250 acre woods course and mx courses. They also sponsor national AHRMA vmx and cross-country races. Then there is SEVMX with races in my area at assorted tracks. It looks like the 175 can run in less than 200cc class they have, but regardless, it's like you said, it's the smiles and the journey that I'm looking forward to. The 175 may not be the best choice but sounds like it should be a lot of fun to build. The 125 will not be as big of a challenge and I've raced them back in the 70' as a teen and had a blast! All Hodakas are awesome bikes, no matter the model you choose.

[Old Rat]

Picture of project 175 VMX bike I'm starting with.

[Old Rat]

Starting to break it down, split the case and strip the frame.

[olddogs]

Looks like you have a decent platform to begin the journey. With a track and a class that may smooth out some of the disadvantages a 175 would give up in the open class, looks like fun in your future.

If you dont plan on a big $$ reed valve upgrade, I found the best bang for my racing bucks were in the carb and head. A 3 vane venturi divider setup in a 250 carb, and torque groves added to the head eliminated a horrible detonation and spark knock issue that plagues the Hodaka 175/250 engine once you increase the load and HP. These 2 mods were under 300 bucks and made tuning a piston port engine much easier. You can swap on a 250 cdi on with no modifications. I just found it easier and more reliable than points. The adjustable stater plate makes timing changes simple.

[Old Rat]

I was looking at the PVL ignition(458115 stator 4000 Winches Rotor 940 Backplate 94 mm?) for it. Looks like I can get one from ebay for around $360. On the Hodaka-parts site they list the 250 cdi unit for $221(I assume they are available). Which would be better to go with?

[olddogs]

I have only used the pvl systems on our 125s. They were simple to install and time. Been running them for a couple years now with zero problems. I had a number of Sl250 parts bikes so stealing the cdi units was a 20 minute job. I used to be able to pick up complete 250 engines for 50 bucks 20 years ago, so I had lots of spare engines laying around. For some reason thought you had access to the parts. Never installed a pvl on my 175.

[Old Rat]

I do have a fully restored SL250. Just didn't want to start robbing parts from it.