how can i gets more RPM in my yamaha

[John (Taylor) Gabrowski]

Doing all this is a steep learning curve that is no small feat. I learned because others took the time to mentor me, teach me. I made it a point of being their good student and a good listener. I was not afraid to get down to what I learned and did it so carefully knowing I would be observed by my teachers. Money was not plentiful being a student when it came to making mistakes myself that could potentially ruin things. From all that I managed to cook only one engine, only one piston in it, being a little overzealous with the top carb's high speed jet needle tunning it on a Merc 55H stock racer back in the middle 1970s.

First thing you need to become is a good student and then find your mentor amongst others who will guide you because you are there to listen, learn and be helpful and thankfull for the privilege being taken on by that mentor.

Listen to old TV shows like Kung Fu? That was the only TV show I can recall that taught some common sense with a fictional story line.

[Roy Hodges]

Listen to old TV shows like Kung Fu? That was the only TV show I can recall that taught some common sense with a fictional story line.
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That's right, grasshopper !

[pr-550yamahadriver]

Are you think I 'm a NEWBIE but i am double galician champio PR-550 AND 4 OF THE WORLD IN 2007 MY FATHER IS 2nd OF EUROPE AND THE CATEGORY OF OUR TEAM IS CONSIDERED ONE OF THE BEST PERFORMANCE IN THE NORTH OF SPAIN

BUT THE PROBLEM IS WE DON´T KNOW OF PERFORMANCE ELECTRONIC PART....

BUT THANKS EVERYBODY

[John (Taylor) Gabrowski]

The last time I saw anything from Vigo was its part as a location a U-Boat was going in the movie I have in my library called "Das Boot".

When it comes to electronics on these engines there are just so many good ignition systems out there. Some very simple that carry every manner of flywheel weight. I am prone by background to getting rid of excess weight to get quicker spin up. On these older technology Mercury 4s you can get rid of everything to just a low ounce weight core, belt drive it with battery CD ignition with next to no drag and very problem free so you tend to stick to it or in the alternative a belt drive, very low drag high output mechanical magneto at some 20+KV. Keeping things simple and plentiful renders reliable ignitions.

The only thing I don't ever see is the "open" pipes systems of there in Europe we are use to around here for deflector/crossflow engines. It gives them an Indy or Formula One racecar sound all their own as 2 strokes that make for racing excitiment you just don't get out of expansion chamber exhausts. Kind of makes the particpant deaf on the long run though!

[pr-550yamahadriver]

A Really Nice Shot

[Miss BK]

[QUOTE=quty06;64557]can u show us with pict(s). QUOTE]


I wish I had pictures of all of this, but I don't. That one photo in my avatar is one of the few I have of the boat at all.

During my last year of racing, one person was doing the majority of the "radical" work on my Yamaha (Jimmy Johnson) - but there were 2 or 3 others that were experimenting with these 30hp motors too. Glenn Schaid and Rick Hoffman to name a few.

They all were pretty tight lipped about what they were doing.

One time when going to our usual "test" lake, I accidentally came upon several of these guys hammering on the lower pan of one of the Mod C racers. As soon as they saw me walking up they swarmed me, saying, "YOU WILL NOT TELL A SOUL WHAT YOU JUST SAW!!!!"

I laughed, because all I saw was someone with a hammer, smacking the lower pan. What did they think I'd do?...run off and tell our competition; "They are making new modifications - he's hitting his cowling with a hammer!" LOL

But it did make me feel good that they had assumed I was that mechanically savvy!

Only later did I learn they were actually adapting the motor with 50hp carbs and they needed to break a hole into the lower pan to make these bigger carbs fit. (I didn't even notice the big carbs at all!!!)

I only saw that special tuner one or two times - I saw four flat pieces of metal, hand welded together into a box, tapered at the end.

One time, the weld on the tuner didn't hold, the tuner slipped down without anyone knowing what happened. I ended up having a VERY miserable 5 hours at the Parker mini enduro and the following Havasu mini race, running 65mph instead of the usual 75-80mph. I didn't find out what was wrong until after getting run over a week later at Havasu.

A friend looked inside the tower and saw the broken weld.

That was the last time I saw that motor. My injuries meant I'd be out for at least a year. I sold the motor to the builder, mostly because he didn't want his engine secrets being sold (and discovered) by his competitors.

I think my old builder may be a member here on BRF --- Ron may know how to get in touch with him....

Sorry I couldn't help more....

[quty06]

Thanks Miss BK,
here a pic, guys same moda with u

[pr-550yamahadriver]

thanks for the info but i can´t use all of then because the UIM rules are very strics but grace mille XD

[tsrt]

I bought that last super mod c from ron, its run 78mph on my gps before i melt the piston. This motor really amazing, it is an art of engineering

[tsrt]

Miss BK ,

I need help on timing setting, my mechanic wrongly set the timing thinking same timing with stock and melt the piston