Ace 90 mystery machine

[Jakefoo]

Hey all, i picked up this beauty a few months ago. The gentleman i bought it from was in Idaho. He bought it from a fella in Oregon. Its now with me in Washington. Frame tag puts it a 1965 Ace 90. Im just looking for some veteran Hodaka opinons and thoughts.
It ran really well till it didnt. I kept fouling plugs and noticed the head gasket leaking. So then the fun began. I wanted to tear into the day i bought it to figure out what i had. But it was running so good i couldnt break the "if its not broke dont fix it rule." Heres what i have.
It looks like an Ace 90 cylinder thats been bored out a couple times. A&A head without a part number. The 2 that i have found online had a part number stamped where mine says "blank." Mikuni vm24. 115 main jet and 30 pilot jet. The intake manifold looks homemade. Swingarm has been extended, homemade pipe maybe, and the tank is off a Yamaha. Both tires are 3.00x18.
Im guessing why im fouling plugs is from the head gasket leak. The gasket was copper. I have a new aluminum one im going to try.
Sorry for the long winded post. Please chime in if you have any info or advice.
Thanks everyone.

[viclioce]

Wow! Cool find! Looks like it was raced!

From what I can see in the piston pic, that looks like an .080 overbore piston. 80 thousandths is the biggest piston they ever made! So there’s no more boring that cylinder.

I would check with Terry Larson st Hodaka-Parts.com & see if he has a smaller bore cylinder with which you can replace it. There are also Ace 90 parts available from Bruce Young, if Terry doesn’t have what you need. But Terry can also supply you with the needed piston, rings & top end kit for the cylinder as well. So I would start with Terry first.

Definitely looks like the fuel tank is an old Yamaha tank. The Ace 90 used a chrome tank which looks like this, with a red gas cap. Also, the 90’s originally had 17” rims. So those are replacements.

Lots can be done! I took a much worse condition Ace 90 and turned it into a nice looking & running dirt bike! Yours is much further along than mine was!

[Bruce Young]

Great find, that head is an A & A head, built by company that was in the SF bay area in the old day,s It built all kinds of racing parts for all brands of M/c, one of the owners and operators of the company was a would famous rider Chris Carter, whom later went on to be a top notch mx,er for factory Yamaha, and part owner in now Motion Pro, now retired and great ambassador for Vintage bikes he pops up all over the world riding him great machines, I am proud to say we are long times friends within Dist 36, Northern Calif. .Those heads for a Hodaka, are not seen so much these days. Thanks Great looking bike and please keep it just as you found it but after you get it running and have a fun time riding it. If you need help with getting it running , Please call and if we can,t help we will find someone whom can, Bruce Hodakapartsidaho.com 1--208--571--2823, probably something simple.

[taber hodaka]

I think it is a 30 over piston?? Clarence ................ beautiful bike!

[matt glascock]

Absolutely awesome flat tracker time capsule. Superb. I wouldn't change a thing. I wouldn't even start it though without a complete overhaul including all new seals and bearings and an upgraded kick roller retainer. As tempting as it is to run it as is until it isn't, some serious mischief can occur that could potentially wreck the motor. What an awesome bike. Congratulations. Get an official workshop manual and you're half way there. Indispensable.

[Jakefoo]

Thanks for the responses and advice. Yeah i love it. Im glad you guys like it as well. I'll keep it together and take good care of it. Ive applied for the title which takes about 3 years.
Before the head gasket went it ran great. First kick and idled fine. Pretty peppy too.
Im super happy to own it. Ive had numerous Yamaha and hondas and was currently working on a model 92 when i found this beauty. By far, the coolest bike ive ever owned.

[Stever]

VERY cool bike.
What Matt said for sure, including new main bearings and seals. And a leaking main seal on the clutch side could be the source of your plug fouling.

-Stever