Ace 90 engne locked up

[swimmer_spe]

My father's 67 Ace 90 engine is locked up. He did not tell me how it happened.

This means a rebuild will happen sooner than I expected.

Since I do not know if I am replacing major components like a piston or jug, or worse, I am waiting till I tear it apart before I come up with a list of parts to replace.
Should I just replace the bearings and seals and rings regardless? I am already there. Anything else that is worth replacing since I am at that point?

[taber hodaka]

What is the history? Did it lock up just lately? Has it been rebuilt before. How long has it sat? How many miles? If the rings, piston and bore are clean and within tolerance?? I would rather a old tight quality bearing over a new cheap one. ----Clarence

[swimmer_spe]

What is the history? Did it lock up just lately? Has it been rebuilt before. How long has it sat? How many miles? If the rings, piston and bore are clean and within tolerance?? I would rather a old tight quality bearing over a new cheap one. ----Clarence

My father owned it from new.
It has had a new piston and jug before.

It has sat about 7 years, not running, but stored inside a garage. Mileage? Ha Ha Ha! With the stores of where he went with it, 10s of thousands....

I would hate to put it back together, ride it foor a year and blow a bearing when I could have replaced it and got longer out of the rebuild.

[Bullfrog]

. . . um, there is no guarantee the old bearing was a thing of beauty when it went in, and the ageing didn't improve it. (and no reason to put in a "new cheap one") Yup, new bearings and seals while you are in there.
Ed

[taber hodaka]

I worry that someone would put in a bearing like listed on ebay for $1.04 delivered. I would suggest American, Japan, or german Ect. I have seen some that are a very poor quality. Also only in my opinion seals really can harden and need replaced. Clarence

[thrownchain]

Paul sells an overhaul kit which has all the bearings, bushings, seals, and gaskets you need to update your motor. If the motor is set up from setting, a quick hone and new rings may get it going again.

[swimmer_spe]

I worry that someone would put in a bearing like listed on ebay for $1.04 delivered. I would suggest American, Japan, or german Ect. I have seen some that are a very poor quality. Also only in my opinion seals really can harden and need replaced. Clarence

I won't be buying my parts from Ebay.

[swimmer_spe]

Paul sells an overhaul kit which has all the bearings, bushings, seals, and gaskets you need to update your motor. If the motor is set up from setting, a quick hone and new rings may get it going again.

That is the kit I plan on getting, plus whatever else is needed to fix the engine from being locked up.

[Hydraulic Jack]

If it was running the last time it was parked, and now it is locked up, which I assume to mean you have tried the kick starter but the engine won't turn over, it is most likely simple corrosion that has caused it to lock. The bore is iron, and the piston aluminum. These two metals don't coexist well over time. However, it doesn't take much to cause the engine to not turn over, and while I would not force the issue with the kick starter, I would not hesitate to use a wrench on the crank nut to see if it won't wiggle loose after being exposed to some PB Blaster down the spark plug hole. If reasonable pressure doesn't break it free, take it apart. If you get it free and it runs, overhaul is up to you, but still a good idea.

Assuming you split the cases, replace all seals no matter how they appear or feel. Even if they were just done a year ago, if you split the cases, that's the time to replace seals.

Bearing quality varies with country of origin. I would not use Chinese parts of any sort. Japanese bearings have shown to be highest quality these days. I have yet to see a German bearing, but have seen Czech Republic bearings. Actually, these are not a problem since much of old German manufacturing wandered over the border into Czechoslovakia in much the same way American manufacturing has migrated to Mexico. I don't know what source Strictly Hodaka uses for its seals and bearings, and I would ask first before buying a kit. Anything from eBay is buyer's risk.

While you are going over parts, check the ignition parts for pitted points or broken wire insulation. We tend to ignore wiring, but it gets brittle over years of sitting around, and magneto wiring lives in a harsh environment.

Be sure to clean the carb. Take it completely apart, verify the passages pass air, remove debris and sludge. If you have a dunk tank of carb cleaner, remove all rubber parts and soak well. Replace the air filter. Check tires and tubes for cracks and signs of ozone damage. Clean and lube the chain. Lube the control cables. Grease the steering bearings. Clean the brake shoes..... you get the picture. If you sat for seven years, would you go straight out on the football field to play, or would you warm up a bit first?

[viclioce]

I've not heard such bad reports about things from China. What is it about things they make which leads you to believe they are prone to premature failure? Just curious. Welcoming any opinions & experiences. Victor

[thrownchain]

And as long as it's open check the clutch plates, springs and bushing. Anything that is a "wear" part needs to be checked.

[Bill2001]

Chinese bearings have a long-time rep of being iffy. Do a google on "Chinese ball bearings vs german" for more info. Best advice is don't risk it.

[swimmer_spe]

My father heard a "crunch" as he was trying to start it.

[taber hodaka]

Victor I am not saying all things from china. But I have some experience with their bearings and maybe they were just substandard. I had to take them back out once when they were still new. They were looser than if they were eating dirt or that I had 5,000 miles on the engine. Try them Victor 10 bearings delivered for $10.40 is a lot of bearings for cheap. ---Clarence

[dirty_rat]

The "Crunch" he heard could be from a worn kick retainer. When the kick starter retainer (which is inside the engine) gets worn, it causes the kick starter to slip/skip and causes a awful "crunch" noise. And, because it slips, the engine doesn't turn over.

As for things from China, just remember, the engines in the smaller BMW's are now made in China. Just food for thought.

[Bill2001]

When I redo my engine the stamped sheet metal roller retainer will be replaced with the aftermarket machined one. If the kickstart fails, I don't know if the bike can be bump started with an inop kicker.

Chinese parts can be hit and miss with
??? QC

[Bullfrog]

Yes, the bike can be bump started when it has a failing kick start system.
Ed

[Hydraulic Jack]

I would hope it could,be bump started. Otherwise I don't know how I restarted my engine so many times in races without finding neutral.

[MTRob]

When I bought my 3 94 Wombats I tried to kick them over. two would turn over one wouldn't so I plulled the plug shot good oil down the cylinder and waited a day or two then kicked it over it broke lose and had pretty good compression. I was impressed. But whats in side will need work. Maybe another projet for Taber If I get my first one back
MTRob