Applying template more than once on an element - xslt

Question

Im struggling a bit with the following. Given that items may contain several part and spec pairs, i want to process each pair, or apply the template to the item more than once.
Currently, each item is processed once and I'm missing the second part.
<figure>
<list>
<item>
<part>
<p>74174</p>
</part>
<spec>
<u>a1</u>
</spec>
<part>
<p>75375</p>
</part>
<spec>
<u>a4</u>
</spec>
</item>
</list>
</figure>
Stylesheet:
<xsl:if test="$a = 'abc'">
<xsl:apply-templates mode="pt" select="/figure/list/item" />
</xsl:if>
<xsl:template mode="pt" match="item[./part]">
<xsl:call-template name="ptt">
<xsl:with-param name="p"><xsl:value-of select="part/p"/>
</xsl:with-param>
<xsl:with-param name="pr">
<xsl:if test="spec/u">
<xsl:element name="pr">
<xsl:element name="rpn">
<xsl:value-of select="spec/u"/>
</xsl:element>
<xsl:element name="rtn">Alt</xsl:element>
</xsl:element>
</xsl:if>
</xsl:with-param>
</xsl:call-template>
</xsl:template>
I simplified and cropped the code a bit since it goes on and on and on..
Edit: This next one is generating my new elements based solely on the input params
<xsl:template name="ptt">
<xsl:param name="p"/>
<xsl:param name=u"/>
</xsl:template>

Answer 1

It seems that you are unwilling to show a self-contained and complete example (for your future questions, do not make it quite so hard for people to help you), so I am not sure whether the following is helpful to you.
Assuming the XML input you have shown, the stylesheet below demonstrates a way to call a named template for each pair of spec and part elements, as you requested.
It uses xsl:for-each-group (which is exclusive to XSLT 2.0, but you did not tell which version of XSLT you use) to define groups that start with a part element, resulting in the said pairs. Then, for each group, the named template ptt is invoked with p and u as parameters.
Stylesheet
<?xml version="1.0" encoding="UTF-8" ?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="2.0">
<xsl:strip-space elements="*"/>
<xsl:output method="xml" encoding="UTF-8" indent="yes"/>
<xsl:template match="item">
<xsl:for-each-group select="*" group-starting-with="part">
<xsl:call-template name="ptt">
<xsl:with-param name="p" select="current-group()[1]/p"/>
<xsl:with-param name="u" select="current-group()[2]/u"/>
</xsl:call-template>
</xsl:for-each-group>
</xsl:template>
<xsl:template name="ptt">
<xsl:param name="p"/>
<xsl:param name="u"/>
<result>
<part><xsl:value-of select="$p"/></part>
<spec><xsl:value-of select="$u"/></spec>
</result>
</xsl:template>
</xsl:transform>
XML Output
<?xml version="1.0" encoding="UTF-8"?>
<result>
<part>74174</part>
<spec>a1</spec>
</result>
<result>
<part>75375</part>
<spec>a4</spec>
</result>

Answer 2

Well with call-template and a parameter <xsl:with-param name="p"><xsl:value-of select="part/p"/></xsl:with-param> you are making it harder than it needs to be, assuming XSLT 1.0 the <xsl:with-param name="p"><xsl:value-of select="part/p"/></xsl:with-param> fills the parameter p with a text node of the string value of the first element selected by part/p. So at least use simply <xsl:with-param name="p-elements" select="part/p"/>, then the parameter value is a node-set with all p elements.
Better yet, simply use template matching and apply-templates consistently, then you don't have to struggle with call-template and with-param.
Based on your comments you could just use
<xsl:template mode="pt" match="item[part]">
<xsl:apply-templates select="part" mode="pt"/>
</xsl:template>
<xsl:template match="part" mode="pt">
<xsl:variable name="spec" select="following-sibling::*[1][self::spec]"/>
...
</xsl:template>