dlnoss

Is it running on both cylinders? Running good when not idling? It's not spitting any coolant out the exhaust? If you raised the compression, each hit can be a little more pronounced at idle.

There are differing opinions for sure. I sell 1/2", 3/4", and 1" reed spacers to one builder who builds some pretty mean drag motors, but I don't make any claims about them.

I must sell them WAY to cheap!!

I'm not sure I'm understanding. Is it happening with the 19cc domes or the 18cc domes or both?

Do your cylinders still have the longer studs for the Pro Design head or the shorter stock studs?

It won't hurt it to not have it advanced. Advancing the timing can increase the tendency to detonate as will increasing compression.

Normal price is $65 for domes and $16 for an oring set

I have them. With the HQ discount it would be $72.90 plus shipping for domes and an oring set. Someone might have some used domes for less. -David

Yamabond will work fine or clear RTV. Try just tightening them first. You don't have to remove the head to remove the fitting.

I use sealer on the fitting bolt threads to prevent coolant from leaking through the threads and to keep the screws from vibrating loose but: If it is leaking there first check that the two socket head screws are tight. If they are tight and it's still leaking, remove them, coat the threads with silicone sealer and then reinstall them. If you go as far as to remove and reinstall the fitting, check and make sure that there isn't a burr on the hole keeping the fitting from fitting up against the head flush.

I've had good experiences with Moto-Man and Ronnies.

21's would probably be better. Is a shop doing the porting?

Most of the time you can run premium pump gas with 21cc domes. In your profile it looks like you are ported running advanced timing. What is your elevation and your compression with the 22cc domes? -David

If your engine is stock except for what you mentioned and you want to run pump gas, I'd go with 21cc domes. If you want to run a mix or straight race gas, you could go with 20cc or 19cc domes. I usually don't recommend anything smaller than 19cc at sea level without a welded crank.

If you don't mind the down time, you can send the head to me and I'll check it to see if it's been modified. It would give you a starting place. If you were going to do this, it would be good to check the compression before removing the head.

17cc domes are REAL small for sea level, a stock crank, and anything but race gas. Are you ported? The Yamaha shop may want to do a total rebuild for you.

If you are having an engine builder do your porting, they would be the best person to recommend a dome for how they are porting it. If your engine builder has custom recommendations, let me know. -David

I have them. Check out http://www.nossmachine.com/yamaha_banshee_parts.htm -David

I guess you are running a base spacer plate. You are welcome to call if you want. There are lots of things to consider like what compression you want, what it is now, if your cylinders were ported when you did the stroker, what your deck height is, etc.. -David

The best dome also depends on how your stroker is set up and the porting. Is your head 'stock' now or modified?

There are a bunch of guys here that have cool jobs. Engineers, technicians, business owners, a BlackHawk Pilot (Proquad101 hasn't responded to this topic yet), lobster boat owners. It's a cool group. When you look through the replies to this topic you gotta wonder what the people who are trying to shut down 2-strokes and quads in general do for a living. Most of them probably do nothing except whine about those of us that actually have a life.

Yea, it would be fun to get paid for tearing stuff up.

I ship to both. PM your address to me and I'll figure shipping. -David

I've shipped several heads to Australia. JMC Racing has ordered heads from me before. I don't know if he has any left in stock.

I've done a lot of things like systems engineer (mainframe), skydiver pilot, aerospace design and manufacturing, non-destructive testing, and others things. Now I have a CNC manufacturing shop. I work and live on 23 acres in Oklahoma. I design and manufacture machined parts for Quads, Dirtbikes, some aerospace and oil/gas related stuff.