Ok guys, don't laugh too hard but I have a legitimate question. A co-worker who rides a Honda TRX-250R recently inherited a 1988 Zilla. Modifications to it include a cool head, Paul Turner pipe, PWK 39 carb, & no air box lid. Porting & internal engine work is unknown. He cannot successfully kick start it so he says he always has to pull start it. He also says he likes the way the big zilla rides when he cruises around but that the power scares him so he just rides the Honda. I rode it & soon found out the 3rd gear is not holding as it slips back to 2nd under hard throttle. My question is that since the engine has to come apart for a tranny rebuild, is there anything that can be done to de-tune a zilla for the beginning rider or wife / gf?

Besides fixing the trans issues, my ideas include getting the W-C-R pro mod package for the gears, billet aluminum thrust washers, fix the squish but re-chamber the head (or double head gaskets) to lower the compression, and put an air box lid on. I see no reason for him to get rid of the pipe but what about power valve adjustments? TM-34 carb? What are your ideas?

I'm thinking a mid 40 hp build would work and could be tuned up as rider skill & confidence increases.

It has a coolhead, so have the dome squished correctly and cut for lower compression. This should ease starting and enable him to use 93 octane.

People that pull start their **** is embarrassing. I see it all the time in the parking lot at the dunes. It just shows your lack of care and knowledge of your machine. 

I would get it fixed and running correctly, get him in the sand so some of the power is soaked up and he will adjust very quickly to the 500. You could always throw an fmf pipe on to knock down the power a notch. And tell him he could always just keep his thumb out of it a little. 

Thanks for the replies. I'm probably gonna help him with some of the wrenching on this bike. I'm sure that the Sand Stars he has will be forgiving in the sand. But for a typical zilla, it is alot quicker than his TRX-250 (stock with an FMF & open element air filter). I know we are all searching for ways to go faster & quicker so no one ever tries to slow a 500 down. The reason I was asking is because how many of us have a friend that is new to performance quads & get a good deal on a zilla before they are ready for one? Or some of us that have a significant other that wants or has a 500 but don't need it to go racing with the guys.

I really think that dropping a 250 in is your best bet.
It probably wouldn't take any modifications at all.
Makes it a lot easier to start and there's probably 20 guys here that'll trade a running 250 engine for a 500 that needs transmission work.
Just think about how easy it would be to work on...


Other than that, dropping the compression would be the first thing to do in de-tuning a zilla, followed by a smaller carb.

A lession on how to kick start a big bore single cylinder may be all he needs.  Does it appear that the top end is in good condition.  A worn out engine will be difficult to kick start and will always pull start easily.  A fresh top end with a carb that is set up correctly is the key to most starting problems. 

Check the air gap on the plulser coil on the stator.  It should be in the .015" to .030" range.  Lowering the compression alot may help if he is a 98 pound weakling and will make the engine a little lazy.  Putting the air box lid on will soften up the midrange and top end power. 

Do like they did with the 80s.

Keep the thumb throttle on, drill out the housing and put in a set screw, it will limit the amount of throttle they can use but since it is a 2 stroke it could limit the riders ability to make adjustments with the throttle as they ride and observe changes in the motor at different RPMs.