Suzuki RM 125a


5 replies to this topic
  • Ruro

Posted 06 June 2012 - 10:39 AM

#1

Hi ,

How can I tell the difference between the Suzuki RM125a and the b cylinder? Is there any way to measure this or is there an easy way to tell them apart?

/Ruro.

  • greg-15

Posted 07 June 2012 - 06:32 AM

#2

Hi ,

How can I tell the difference between the Suzuki RM125a and the b cylinder? Is there any way to measure this or is there an easy way to tell them apart?

The cylinders look the same but have different cylinder dimensions.

/Ruro.

In 1977 on the "B" model, Suzuki went to the 54 x 54 mm bore and stroke which gave it more and better power band. The 1976 "A" model had a 56 mm X 50 bore and stroke which was the same dimensions as the earlier TM models. The 54 X 54 mm bore and stroke dimensions have been used then on all 125 motocross bikes by Suzuki to today.

The Bore on the 1976 "A" model is 56 mm and has a bridge on the exhaust port.

I had a 1977 "b" model back in the day which ran well and was very reliable. I now have a 1976 "A" model which I am restoring now and converting into a Marty Tripes RM100 Revenge bike.

  • Ruro

Posted 07 June 2012 - 11:13 AM

#3

In 1977 on the "B" model, Suzuki went to the 54 x 54 mm bore and stroke which gave it more and better power band. The 1976 "A" model had a 56 mm X 50 bore and stroke which was the same dimensions as the earlier TM models. The 54 X 54 mm bore and stroke dimensions have been used then on all 125 motocross bikes by Suzuki to today.

The Bore on the 1976 "A" model is 56 mm and has a bridge on the exhaust port.

I had a 1977 "b" model back in the day which ran well and was very reliable. I now have a 1976 "A" model which I am restoring now and converting into a Marty Tripes RM100 Revenge bike.


Thanks Greg.

So if I understand correctly the B-cylinder does not have a bridge on the exhaust port?

Do you have a picture of your RM 100 cylinder? I possible do you know the height of the cylinder?

/ Rune :-)

  • greg-15

Posted 08 June 2012 - 07:06 AM

#4

Here is a picture of the RM125A cylinder. Notice a bridge on the exhaust port. I am 99 percent sure the 1977 125B cylinder does not have this but please check a 1977 RM125B engine diagram to make sure.

http://i1191.photobu...15/DSC04623.jpg

http://i1191.photobu...15/DSC04623.jpg

  • greg-15

Posted 08 June 2012 - 07:20 AM

#5

Hi ,

How can I tell the difference between the Suzuki RM125a and the b cylinder? Is there any way to measure this or is there an easy way to tell them apart?

/Ruro.

Here are pictures of the 1977 RM100B cylinder. This cylinder also has a bridge. This cylinder was based from the 1976 RM125A cylinder because the RM100B still had the 50 mm stroke and had the 1976 crankshaft and rod.

For information, the 1976 RM100A complete cylinder was based on the 1975 RM125M model and was totally different jug. This is probably confusing but it is important to know if your looking for the correct cylinder. Are you building an "A" or "B" model?

http://s1191.photobu...nt=DSC04625.jpg

http://s1191.photobu...nt=DSC04624.jpg

  • david33mason

Posted 23 October 2012 - 06:54 AM

#6

Hi Guys just picked up a 76 Rm100 in a pretty sorry state, do you have any good sources for parts? Any particular areas to pat attention to?
thanks in advance




 
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