Needing opinions on a new head.

[new2scootin]

I was pulling the plug today for an after WOT run read on my 2011 Toa Toa with a 47mm BBK, UNI dilter and jetted 85 main and 35 idle. All else is stock. Long story short I stripped out the plug thread in the head. Now I need a new stock head as I want to stick to the stock head for it's compression over a 47mm head. Does anyone have any suggestions on one I should get that won't cost me an arm and a leg. Keep in mind I only paid $100 for the scooter

[PirateLabs]

Just install a heli-coil or other thread insert and keep the head. Total cost about $5.00.

Bill

[jeff84]

idk where you find helicoil kits for 5 bucks. last time I bought one it was about 20 and I had to buy an odd sized individual drill bit. still cheaper than buying a new head though. also if you go that route use red/high temp thread locker on the insert.

[new2scootin]

I priced a helicoil for my head and it was $40 for the kit. Cheaper to buy a cheap head

[ratdog]

I looked over at scooterdomain and a whole head assembled with valves I’ds like $36.95. I’d just get that instead of doing a heilcoil.

[PirateLabs]

www.ebay.com/p/Helicoil-Thread-Repair-M10-X-1-Drill-and-Tap-12-Inserts-Fine-Thread/633652822?iid=381747894513&chn=ps

Here is the size for a 49cc (I am pretty sure) and the price works out to be $2 for each insert. This is a kit and you get the drill and tap as well for $25.00 but, since I grew up in the machining business, all I ever needed was a single insert and not the kit as we already had their taps and any size drill I needed. If it were me and I had any mileage at all on that head, for $35 I would buy a new head and get nice fresh, clean valves. Just be sure to replace the gasket and use a torque wrench on the bolts.

Bill

[humanshield]

BTDT
Stripped out a Znen head a year or so ago. Tried to repair the threads. (Spent $50 on inserts and taps etc)
It failed soon after. Went to the next size up...no go. Bought a new head $65 problem solved.

Get another head. The inserts are so small they aren't as reliable as they can be on regular sized spark plugs and steel heads. Sometimes they work....but who wants sometimes?  Could be I just didn't get it right.  Who knows.

Check your compression. If it's too high, you'll be getting another motor before long. (from my experience)

As always....YMMV

PS, I think I have some correct size inserts I could sell

[new2scootin]

New head should be here today with a Glixal A9 cam. Cant wait for the mail to run

[new2scootin]

Ok so the head came in today and it has a overall smaller combustion chamber than the one that came with my 47mm BBK and the stock one I took off in the first place. I ordered a new 49cc head and It has what looks to be a stock combustion chamber ( the same hemi-spherical chamber as both stock and the 47mm BBK ) but with little to no taper going around the actual hemi-spherical chamber itself resulting in a smaller overall chamber once the piston is at TDC. The one I got in today only has maybe 1/8 inch of taper around the combustion chamber while the stock and BBK heads have 1/4 inch or more of taper going into the hemi-spherical chamber. Anyway I havent had a chance ro do compression tests but it def runs a lot stronger in the low to mid range. I didnt get to install my A9 cam since it got delayed during shipment. Cant wait to out that thing in there.

[ratdog]

Hate to say it, but I’m kinda glad your doing the cam as a separate step. That wat we can see of the cam is doing you any good. I would love you to do a couple tests before you do the cam. Something more then just “feels stronger”. The tests I use are 0-25 (time). 0 to 1/2 mile (time and speed) and ofcourse max top speed but on the same stretch of road both before and after.

I’m doing almost the same thing. The big bore kit that I bought came with a head with oversized valves. Well I don’t think she is all that she can be so I’m trying a “big bore” head with normal valves. OK, I’ll be honest, I put the bike back together and just happened to be going the same way, at the same time, as my buddy that a put a big bore kit in his bike. Well his bike pulls mine a good two bike lengths in about the first 60 feet of a drag race. After that, I start catching up, and after a half miles I’m doing 37mph to his 36 mph.

Of course, mine is not broken in yet, and I haven’t done any plugchops to get the mixture perfect, but still my ego is very bruised that he finally beat me. That, of course is only a temp problem, so I just had to get a “stock valve” head with a 50 mm chamber to try.

I have built engines for customers that had bigger valves but no port work that actually hurt preformance. Thes did make a great base for one of my famous porting jobs!

[new2scootin]

Aug 6, 2018 21:14:44 GMT -5 ratdog said:

Hate to say it, but I’m kinda glad your doing the cam as a separate step. That wat we can see of the cam is doing you any good. I would love you to do a couple tests before you do the cam. Something more then just “feels stronger”. The tests I use are 0-25 (time). 0 to 1/2 mile (time and speed) and ofcourse max top speed but on the same stretch of road both before and after.

I’m doing almost the same thing. The big bore kit that I bought came with a head with oversized valves. Well I don’t think she is all that she can be so I’m trying a “big bore” head with normal valves. OK, I’ll be honest, I put the bike back together and just happened to be going the same way, at the same time, as my buddy that a put a big bore kit in his bike. Well his bike pulls mine a good two bike lengths in about the first 60 feet of a drag race. After that, I start catching up, and after a half miles I’m doing 37mph to his 36 mph.

Of course, mine is not broken in yet, and I haven’t done any plugchops to get the mixture perfect, but still my ego is very bruised that he finally beat me. That, of course is only a temp problem, so I just had to get a “stock valve” head with a 50 mm chamber to try.

I have built engines for customers that had bigger valves but no port work that actually hurt preformance. Thes did make a great base for one of my famous porting jobs!

Well I just put in the A9 cam and broke my gates belt and my back up in less than a half mile of riding. I think the belt was actually going all the way off the variator and rubbing the starter gear and ripping the belt apart. I didnt get a chance to put in heavier weights to try and drop my rpms some. All I know it that with the stock 39mm head and a 47mm BBK with a Glixal A9 cam she has PLENTY of low end and middle range power and torque.

[new2scootin]

Aug 6, 2018 21:14:44 GMT -5 ratdog said:

Hate to say it, but I’m kinda glad your doing the cam as a separate step. That wat we can see of the cam is doing you any good. I would love you to do a couple tests before you do the cam. Something more then just “feels stronger”. The tests I use are 0-25 (time). 0 to 1/2 mile (time and speed) and ofcourse max top speed but on the same stretch of road both before and after.

I’m doing almost the same thing. The big bore kit that I bought came with a head with oversized valves. Well I don’t think she is all that she can be so I’m trying a “big bore” head with normal valves. OK, I’ll be honest, I put the bike back together and just happened to be going the same way, at the same time, as my buddy that a put a big bore kit in his bike. Well his bike pulls mine a good two bike lengths in about the first 60 feet of a drag race. After that, I start catching up, and after a half miles I’m doing 37mph to his 36 mph.

Of course, mine is not broken in yet, and I haven’t done any plugchops to get the mixture perfect, but still my ego is very bruised that he finally beat me. That, of course is only a temp problem, so I just had to get a “stock valve” head with a 50 mm chamber to try.

I have built engines for customers that had bigger valves but no port work that actually hurt preformance. Thes did make a great base for one of my famous porting jobs!

So with 47mm BBK and the new stock head with some minor porting and port matching and stock cam my top speed is 38mph. My 0-30mph time was 16.17sec.

After the A9 cam install my top speed is 42mph and I feel that I'm running out of gears not motor. My new 0-30mph time was 12.48 sec. I can cruise 36-38 mph at 3/4 throttle instead of WOT. I would say the Glixal A9 cam I got was well worth the $12 I paid for it. I think I can get better times out of it tho as I'm running really rich and I need to tune my variator as well. So I have Jets and sliders on the way. But long story short the cam makes a pretty good jump in mid to higher rpm torque.

[ratdog]

That’s great news, and I think it is useful because you are comparing just the new cam to old cam. Just wondering, how many RPM are you turning at 42 mph? I’m getting about 5 mph more after the A9, but I’m up at 8500 rpm. I’m thinking I might change the final drive to bring those RPM down a little. Thank you for sharing the results!