what tends to break on the HT bicycle engine?

Re: what tends to break on the HT engine?

jak stoll said:

do the cylinders just wear out, when you beat on them? or do they break rods?
I definatly hear more piston noise from mine durring warm up but not so much when its hot
I was thinking of putting an iron sleeve in one if the bottom ends are pretty bulletproof
Ive spunn the crap out of mine & it seems to be hanging tough but the rod & wristpin seem pretty wimpy
thanks for your input
take care
JAK

Click to expand...

The only thing that has broke on my 'vintage' kings motor was the cast intake. He sent me another 3 weeks after emailing him about it. In the meantime I got a chrome one from Dennis Foster. I'm now over 3200 miles, and it's still going strong. Wish I had bought 3 or 4 of his kits 4 years ago!

Re: what tends to break on the HT engine?

Owner's patience from stuff vibrating loose.

Re: what tends to break on the HT engine?

rcjunkie said:

Owner's patience from stuff vibrating loose.

Click to expand...

yeah. Patience wears thin after a couple of times of going over every bolt. But it's worth the hassle just so you don't go over the bars. Checking the bikes bolts also help.

Re: what tends to break on the HT engine?

Loctite and USA made nuts, bolts, and studs are the way to go. I also use locknuts even on the hot stuff and double nut whenever possible.

Re: what tends to break on the HT engine?

Loctite blue and red are your friends (after warranty periods). I have a bike right now that has over 500 miles and nothing has fallen off.

Re: what tends to break on the HT engine?

I've seen some scuffed cylinder (more than likely due to cold seizure) and wrist pins that were very worn. One grenaded needle bearing engine, and beyond that, any prudent operation will more than likely need only rings, maybe a new cylinder/ring/piston set.

They aren't racing engines, or anything even remotely associated with one.

Re: what tends to break on the HT engine?

how are you going to balance it ? there is only one cylinder these motors are counter wieghted to keep your reciprocating assembly wound up and give it enough velocity to push the piston back to the top of the cylinder when on your compression stroke. i have lightened the piston and pin considerably results = less vibration quicker revs. please post ideas on how your balancing it.

Re: what tends to break on the HT engine?

Hi , I too had a Kings 70 and all was well with it for many a mile until the chain broke and jambed in the front sprocket housing and broke the engine case. It was the strongest running of any of the 5 H Time engines I've had over the last 4 years. The one with the most miles on it is the Dax 65cc that has bushings . I do run it with alot of oil in the mix but it has over 2 k miles on it and still runs as strong as ever.I have learned over the years the the HT quality is poor and the engines are not to be expected to do any more than a putt putt putt around town . Not for performance in any stretch of the imagination. I'm looking for a quality engine that I can abuse and that can take it or be built up to take it. It's come to the point now with my bikes that I tend to go slow and putt around cause I'm tired of braking the things and or going sailing over the bars. Tom in WV

Re: what tends to break on the HT engine?

Yep, the King (not powerking) engine was by far the most powerful and most reliable HT engine I ever owned. I used one with a 44 tooth sprocket to climb mountains that a 65cc HT can't conquer with a 50 toot sprocket.

Re: what tends to break on the HT engine?

First of all the lower end on all of the dissasembled chinese HT engines have not been Bushing even if the top end is they are HA HA UNCAGED NEEDLE Bearing sets that appear to be a bearing short and are not stainless. For one if you want this machine to be buildable this rapture of vibration causing slap is going to need to be tightened up by replacing the needles with the correct sizes(of course) stainless needle bearings, maybe they are case hardened and actually that sound more right than stainless on needles SOrry. But the lengths are different sizes on the same lower end. This alone causes abnormal twisting of the rod at 1000 miles if a text book break in was'nt done. I do agree that they are a 10k engine but don't expect it inspect it if you care! Any of the name branders out there you can expect a good 4500-10k with top end rings and ristpin and bushing replacements at 3000 miles.

I have 5k on mine. So I put new rings in it and it runs awesome. had a little blowby but it wasnt audible. Inspected the upper and lower connecting rod bsh and bearing looked good normal wear. probably another Id say 2500 then Ill put some new rings in it. I could get 8500+ plus out of this Engine.

Oh as far as the lower end it is pretty dependable. Roller bearings shouldnt be lubed by 2 stroke oil so that'ed b eyour time limiting on these as for the 30 mile rule. so the double side sealed roller 6200?? Or 6400?? maybe just might be what your looking for for your mains.

Oh as for porting Id be widening your transition ports and as for the port timing Id lift up the exhaust also widening, The intake volume not to exceed the area block taken out of youaverage exhaust to transition port on the intake and due to our manifold (unless you switch to a honda xr75 carb) in dia. the volume will be duration instead of sample @ rate Thus lowering your intake port 3/16" on mine any way. Then not starving it of burnable gases Id go with a tuned pipe and bore your jet to 70-74 # and run the needle as high as you can yet slightly rich say 28 is what ive ran for 4800 miles. Oh the time you can run them is also limited without the expansion chamber another reason for the volume sizes and timing they use to keep the engine predictably reliable.