New Motor Break-in

[rpage11]

I'm going to break in a new motor on a 250 GS-6 that Chicago Jerry rebuilt for me tomorrow and would like some recommendations/feedback on 2 stroke oil mix, etc.

I have been running it briefly with Amsoil at 80 to 1 with 91 octane.  I have Red Line racing oil and Golden Spector at home on the shelf.

Any recommendations on oil, mixtures and general break in procedures?

Also can I add new mixture to what's in the tank without draining the tank or should I start fresh with all new?

Thanks

Skip Page
Tucson, AZ
//www.robertpagearchitect.com

[skiracer]

I don't think you need to change the oil ratio.  I think what is more important, is that you warm the engine up, and let it cool back down several times.  This will help seat the rings. If you are going to change the make of oil and the ratio, then you should drain the gas tank..............  Have fun!

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[skiracer]

If you are really concerned about it, I would change the jetting before I changed the oil ratio.  Maybe run the pilot and main one size richer for a short period of time.....

1976 MC 5 Original Owner
1982 Suzuki PE 175
1976 Penton 175 XC
1985 20' Hi Point trailer

[454MRW]

I run golden spectro and 93 octane gas mixed at 32.1 and for break-in procedure light acceleration runs for approximately 10 to 15 minutes getting a little more aggressive during each run followed by a cool down period in between each session. After the 3rd session in which fairly hard acceleration and deceleration runs are performed the bike should be cooled until dead cold, and the cylinder head retorqued, and engine mount bolts and other fasteners also checked at that time. After that you should be good to go for competition. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

[firstturn]

I vote for Mike Winters for the job.  His advice is excellent especially for the KTM engine.

Ron Carbaugh

[Larry Perkins]

Ditto.  Mike is on it!

Larry P

[rpage11]

Did it just like Mike said.  Shut it down after 3 runs, which was hard to do.  I really wanted to go out one more time. The top end was wicked fast the last run, but what is really coming on is the low end pull.  Rear tire buried in sand and pull my 225 lbs out in 2/3rd.  
I think Mike wants to see me take the pipe off one more time to get to the head.  Going to try to get it re-torqued tonight so I can go to the track tomorrow.  Rumor has it there's going to be a vintage group out. Thanks Mike

Skip Page
Tucson, AZ
//www.robertpagearchitect.com

[rpage11]

I'm running a 13/52 sprockets and got going about 55-60 mph in 5th gear before I ran out of track and there was still more before 6th.

Skip Page
Tucson, AZ
//www.robertpagearchitect.com

[454MRW]

The Motocross guys will generally gear it down with a larger rear sprocket to avoid the possibility of hitting neutral and launch the bike in second gear. Also I would change the transmission fluid since it should now be ready to race once you tighten the head down, which you might be able to do just by taking the front of the pipe loose and not have to remove it completely. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

[chicagojerry]

i'm glad to hear that that motor is so potent. it has a reed valve on it so i learned a little more abot drilling the pistons on that one too. god luck. chi jer

[rpage11]

You did a nice job Jerry.





Skip Page
Tucson, AZ
//www.robertpagearchitect.com

[rpage11]

quote:Originally posted by 454MRW

The Motocross guys will generally gear it down with a larger rear sprocket to avoid the possibility of hitting neutral and launch the bike in second gear. Also I would change the transmission fluid since it should now be ready to race once you tighten the head down, which you might be able to do just by taking the front of the pipe loose and not have to remove it completely. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1978-1979 MX-6 175 & 250 KTM's
1976-78 125-400 RM's & 79 PE250 Suzuki & 2012 DR650
2007 CR125R Honda
1977 MC250 Maico

That's spot on Mike.  It was 2nd to third shifts that missed.  I'll need a new chain if I go to a 57 tooth.  I don't need 70 mph+.  I'd rather have low end and this engine never had any before Jerry worked on it.  57 tooth??

Skip Page
Tucson, AZ
//www.robertpagearchitect.com

[StephenRead]

Skip the bike looks great.  I'm rebuilding a 75 Hare Scrambler Enduro.  Where did you get the new rear Enduro fender and taillight assembly ? Thanks for any guidance.

[KJDonovan]

Stephen,

DC plastics sells the GS fenders and Paul at Moto Guzzino has the CEV tail lamp assemblies. http://guzzino.stores.yahoo.net/cev92sptalic.html

Thanks,

Kevin